siunitx 2 (23may10)

git-svn-id: svn://tug.org/texlive/trunk@18439 c570f23f-e606-0410-a88d-b1316a301751

32 files changed, 18958 insertions, 18552 deletions

diff --git a/Master/texmf-dist/doc/latex/siunitx/README b/Master/texmf-dist/doc/latex/siunitx/README
index 927521fd0ce..a924ef805d7 100644
--- a/Master/texmf-dist/doc/latex/siunitx/README
+++ b/Master/texmf-dist/doc/latex/siunitx/README
@@ -21,9 +21,40 @@ syntax.  The package includes automated processing of numbers
 and units, and the ability to control tabular alignment of
 numbers.
 
-A number of LaTeX packages have been developed in the past for
-formatting units: SIunits, sistyle, unitsdef, units, fancyunits
-and fancynum.  Support for users of all of these packages is
-available as emulation modules in siunitx.  In addition, siunitx
-can carry out many of the functions of the dcolumn, rccol and
-numprint packages
+Installation
+------------
+
+The package is supplied in dtx format and as a pre-extracted zip
+file, siunitx.tds.zip. The later is most convenient for most
+users: simply unzip this in your local texmf directory and run
+texhash to update the database of file locations. If you want to
+unpack the dtx yourself, running 'tex siunitx.dtx' will extract
+the package whereas 'latex siunitx.dtx will extract it and also
+typeset the documentation.
+
+The package requires LaTeX3 support as provided in the expl3
+and xpackages bundles. Both of these are available on CTAN
+(http://www.ctan.org/) as ready-to-install zip files. Suitable
+versions are available in MiKTeX 2.8 and TeX Live 2009
+(updating the relevant packages online may be necessary).
+LaTeX3, and so siunitx, requires the e-TeX extensions: these
+are available on all modern TeX systems.
+
+Typesetting the documentation requires a number of packages in
+addition to those needed to use the package. This is mainly
+because of the number of demonstration items included in the
+text. To compile the documentation without error, you will
+need the packages:
+ - amsmath
+ - booktabs
+ - caption
+ - cleveref
+ - csquotes
+ - datatool
+ - helvet
+ - mathpazo
+ - listings
+ - pgfplots
+ - xcolor
+The xfrac package is also loaded if available, but is not
+required to typeset the documentation.
diff --git a/Master/texmf-dist/doc/latex/siunitx/siunitx-bug.tex b/Master/texmf-dist/doc/latex/siunitx/siunitx-bug.tex
deleted file mode 100644
index 5dc24b321b4..00000000000
--- a/Master/texmf-dist/doc/latex/siunitx/siunitx-bug.tex
+++ /dev/null
@@ -1,13 +0,0 @@
-\listfiles
-\documentclass{article}
-\usepackage{siunitx}
-\sisetup{debug}
-\begin{document}
-This is the bug test-case document for the \textsf{siunitx}
-package.\\
-Please put your demonstration here, and e-mail to the package
-author.
-\begin{center}
-  \texttt{joseph.wright@morningstar2.co.uk}
-\end{center}
-\end{document}
diff --git a/Master/texmf-dist/doc/latex/siunitx/siunitx.pdf b/Master/texmf-dist/doc/latex/siunitx/siunitx.pdf
index d4361d5c920..d5ceb91d94c 100644
--- a/Master/texmf-dist/doc/latex/siunitx/siunitx.pdf
+++ b/Master/texmf-dist/doc/latex/siunitx/siunitx.pdf
diff --git a/Master/texmf-dist/source/latex/siunitx/siunitx.dtx b/Master/texmf-dist/source/latex/siunitx/siunitx.dtx
index 96b2cfd1d9b..7d26d6aa9b3 100644
--- a/Master/texmf-dist/source/latex/siunitx/siunitx.dtx
+++ b/Master/texmf-dist/source/latex/siunitx/siunitx.dtx
@@ -1,6 +1,5 @@
 % \iffalse meta-comment
-% !TEX program  = pdflatex
-% !TEX encoding = iso-8859-1
+% !TeX program = pdfLaTeX
 %<*internal>
 \iffalse
 %</internal>
@@ -28,12 +27,43 @@ syntax.  The package includes automated processing of numbers
 and units, and the ability to control tabular alignment of
 numbers.
 
-A number of LaTeX packages have been developed in the past for
-formatting units: SIunits, sistyle, unitsdef, units, fancyunits 
-and fancynum.  Support for users of all of these packages is 
-available as emulation modules in siunitx.  In addition, siunitx
-can carry out many of the functions of the dcolumn, rccol and 
-numprint packages
+Installation
+------------
+
+The package is supplied in dtx format and as a pre-extracted zip
+file, siunitx.tds.zip. The later is most convenient for most 
+users: simply unzip this in your local texmf directory and run 
+texhash to update the database of file locations. If you want to
+unpack the dtx yourself, running 'tex siunitx.dtx' will extract
+the package whereas 'latex siunitx.dtx will extract it and also 
+typeset the documentation.
+
+The package requires LaTeX3 support as provided in the expl3 
+and xpackages bundles. Both of these are available on CTAN
+(http://www.ctan.org/) as ready-to-install zip files. Suitable
+versions are available in MiKTeX 2.8 and TeX Live 2009 
+(updating the relevant packages online may be necessary). 
+LaTeX3, and so siunitx, requires the e-TeX extensions: these 
+are available on all modern TeX systems.
+
+Typesetting the documentation requires a number of packages in
+addition to those needed to use the package. This is mainly 
+because of the number of demonstration items included in the 
+text. To compile the documentation without error, you will 
+need the packages:
+ - amsmath
+ - booktabs
+ - caption
+ - cleveref
+ - csquotes
+ - datatool
+ - helvet
+ - mathpazo
+ - listings
+ - pgfplots
+ - xcolor
+The xfrac package is also loaded if available, but is not 
+required to typeset the documentation.
 %</readme>
 %<*internal>
 \fi
@@ -73,11 +103,8 @@ This work is "maintained" (as per LPPL maintenance status) by
 
 This work consists of the file  siunitx.dtx
           and the derived files siunitx.pdf,
-                                siunitx.sty
-                                siunitx.bib,
-                                siunitx.ins,
-                                siunitx-bug.tex and
-                                various .cfg files.
+                                siunitx.sty and
+                                siunitx.ins.
 
 \endpostamble
 \usedir{tex/latex/siunitx}
@@ -85,40 +112,15 @@ This work consists of the file  siunitx.dtx
   \file{\jobname.sty}{\from{\jobname.dtx}{package}}
 }
 \usedir{tex/latex/siunitx/config}
-\generate{\file{si-SIunits.cfg}{\from{\jobname.dtx}{SIunits}}
-          \file{si-sistyle.cfg}{\from{\jobname.dtx}{sistyle}}
-          \file{si-unitsdef.cfg}{\from{\jobname.dtx}{unitsdef}}
-          \file{si-units.cfg}{\from{\jobname.dtx}{units}}
-          \file{si-hepunits.cfg}{\from{\jobname.dtx}{hepunits}}
-          \file{si-fancynum.cfg}{\from{\jobname.dtx}{fancynum}}
-          \file{si-fancyunits.cfg}{\from{\jobname.dtx}{fancyunits}}
-}
-\generate{\file{si-prefix.cfg}{\from{\jobname.dtx}{prefix}}
-          \file{si-named.cfg}{\from{\jobname.dtx}{named}}
-          \file{si-prefixed.cfg}{\from{\jobname.dtx}{prefixed}}
-          \file{si-addn.cfg}{\from{\jobname.dtx}{addn}}
-          \file{si-accepted.cfg}{\from{\jobname.dtx}{accepted}}
-          \file{si-physical.cfg}{\from{\jobname.dtx}{physical}}
-          \file{si-abbr.cfg}{\from{\jobname.dtx}{abbr}}
-}
-\generate{\file{si-synchem.cfg}{\from{\jobname.dtx}{synchem}}
-          \file{si-hep.cfg}{\from{\jobname.dtx}{hep}}
-          \file{si-astro.cfg}{\from{\jobname.dtx}{astro}}
-          \file{si-geophys.cfg}{\from{\jobname.dtx}{geophys}}
-          \file{si-chemeng.cfg}{\from{\jobname.dtx}{chemeng}}
-          \file{si-binary.cfg}{\from{\jobname.dtx}{binary}}
-}
-\generate{\file{si-UK.cfg}{\from{\jobname.dtx}{UK}}
-          \file{si-USA.cfg}{\from{\jobname.dtx}{USA}}
-          \file{si-DE.cfg}{\from{\jobname.dtx}{DE}}
-          \file{si-ZA.cfg}{\from{\jobname.dtx}{ZA}}
+\generate{  
+  \file{siunitx-abbreviations.cfg}
+    {\from{\jobname.dtx}{config,abbreviations}}
+  \file{siunitx-binary.cfg}{\from{\jobname.dtx}{config,binary}}
+  \file{siunitx-version-1.cfg}{\from{\jobname.dtx}{config,version-1}}
 }
 %</install>
 %<install>\endbatchfile
 %<*internal>
-\generate{
-  \file{jawltxdoc.sty}{\from{\jobname.dtx}{jawltxdoc}}
-}
 \usedir{source/latex/siunitx}
 \generate{
   \file{\jobname.ins}{\from{\jobname.dtx}{install}}
@@ -126,8 +128,6 @@ This work consists of the file  siunitx.dtx
 \nopreamble\nopostamble
 \usedir{doc/latex/siunitx}
 \generate{
-  \file{\jobname-bug.tex}{\from{\jobname.dtx}{bug}}
-  \file{\jobname.bib}{\from{\jobname.dtx}{refs}}
   \file{README.txt}{\from{\jobname.dtx}{readme}}
 }
 \ifx\fmtname\nameofplainTeX
@@ -136,60 +136,274 @@ This work consists of the file  siunitx.dtx
   \expandafter\endgroup
 \fi
 %</internal>
+%<*driver|package>
+\RequirePackage{expl3}
+%</driver|package>
 %<*driver>
-%\fi
-%\iffalse
-\PassOptionsToClass{a4paper}{article}
-\documentclass[german,english,UKenglish]{ltxdoc}
-\EnableCrossrefs
-\CodelineIndex
-\RecordChanges 
-\usepackage[final]{graphicx}
-\IfFileExists{xfrac.sty}{\usepackage{xfrac}}{}
-\usepackage{jawltxdoc}
-\usepackage{textcomp,tikz,pgfplots,tocloft,datatool}
-\usepackage[latin1]{inputenc}
+\documentclass[full]{l3doc}
+
+\usepackage{amsmath,booktabs,caption,csquotes,datatool,helvet,pgfplots}
+\usepackage{siunitx,xcolor,xtab}
+\IfFileExists{xfrac.sty}
+  {\usepackage{xfrac}}
+  {%
+    \PackageWarningNoLine{siunitx}
+      {%
+        xfrac unavailable: \string\sfrac\space fraction \MessageBreak
+        will have wrong appearance%
+      }
+  }
+\ProvideDocumentCommand\sfrac{mm}{\frac{#1}{#2}}
+\usepackage[capitalise]{cleveref}
+\usepackage[final]{listings}
+\usepackage[osf]{mathpazo}
+
+% Silence annoying fp package messages
+\FPmessagesfalse
+
+\pgfplotsset{compat = newest}
+
 \sisetup{
-  eVcorra=0.1ex,
-  unitsep=cdot,
-  alsoload={synchem,hep,binary,astro,geophys,chemeng},
-  loctolang={UK:UKenglish,DE:german}}
-\setlength{\cftsubsecnumwidth}{2.5em}
+  load-configurations = 
+    {
+      abbreviations,
+      binary,
+    }
+}
+\DeclareSIPrePower\quartic{4}
+\DeclareSIPostPower\tothefourth{4}
+\DeclareSIQualifier\polymer{pol}
+\DeclareSIQualifier\catalyst{cat}
+%\DisableImplementation
 \begin{document}
   \DocInput{\jobname.dtx}
 \end{document}
 %</driver>
 % \fi
+% 
+%\makeatletter
+%
+%^^A Some short cuts for the tables
+%\NewDocumentCommand\DescribePrefix{m}{^^A
+%  \expandafter\SpecialUsageIndex\expandafter{\csname #1\endcsname}^^A
+%    #1 & \cs{#1} & \expandafter\si\expandafter{\csname #1\endcsname} 
+%}
+%\NewDocumentCommand\DescribeUnit{m}{^^A
+%  \expandafter\SpecialUsageIndex\expandafter{\csname #1\endcsname}^^A
+%  #1 &
+%  \cs{#1} &
+%  \expandafter\si\expandafter{\csname #1\endcsname}
+%}
+%\NewDocumentCommand\DescribeNamedUnit{mm}{^^A
+%  \expandafter\SpecialUsageIndex\expandafter{\csname #2\endcsname}^^A
+%  #1 &
+%  \cs{#2} &
+%  \expandafter\si\expandafter{\csname #2\endcsname}
+%}
+%
+%^^A For creating examples with nice highlighting of code, and so
+%^^A on; based on the system used in the listings source (lstsample).
+%\lst@RequireAspects{writefile}
+%\newsavebox{\LaTeXdemo@box}
+%\lstnewenvironment{LaTeXdemo}[1][code and example]
+%  {^^A
+%    \global\let\lst@intname\@empty
+%    \expandafter\let\expandafter\LaTeXdemo@end
+%      \csname LaTeXdemo@#1@end\endcsname
+%    \@nameuse{LaTeXdemo@#1}^^A
+%  }
+%  {\LaTeXdemo@end}
+%\newcommand*\LaTeXdemo@new[3]{^^A
+%  \expandafter\newcommand\expandafter*\expandafter
+%    {\csname LaTeXdemo@#1\endcsname}{#2}^^A
+%  \expandafter\newcommand\expandafter*\expandafter
+%    {\csname LaTeXdemo@#1@end\endcsname}{#3}^^A
+%}
+%\newcommand*\LaTeXdemo@common{^^A
+%  \setkeys{lst}
+%    {
+%      basicstyle   = \small\ttfamily,
+%      basewidth    = 0.51em,
+%      gobble       = 3,
+%      keywordstyle = \color{blue},
+%      language     = [LaTeX]{TeX},
+%      moretexcs    = 
+%        {
+%          ampere,
+%          ang,
+%          angstrom,
+%          becquerel,
+%          bit,
+%          bottomrule,
+%          byte,
+%          candela,
+%          centi,
+%          color,
+%          coulomb,
+%          cubed,
+%          cubic,
+%          deci,
+%          decibel,
+%          degree,
+%          degreeCelsius,
+%          DeclareBinaryPrefix,
+%          DeclareRobustCommand,
+%          DeclareSIPostPower,
+%          DeclareSIPrefix,
+%          DeclareSIPrePower,
+%          DeclareSIQualifier,
+%          DeclareSIUnit,
+%          DeclareSIUnitWithOptions,
+%          DTLdisplaydb,
+%          DTLforeach,
+%          DTLiffirstrow,
+%          DTLmul,
+%          DTLnewdb,
+%          DTLnewdbentry,
+%          DTLnewrow,
+%          farad,
+%          gram,
+%          gray,
+%          henry,
+%          hour,
+%          Hz,
+%          joule,
+%          kelvin,
+%          kibi,
+%          kilo,
+%          kilogram,
+%          litre,
+%          lumen,
+%          lux,
+%          mathnormal,
+%          metre,
+%          mebi,
+%          micro,
+%          midrule,
+%          milli,
+%          mole,
+%          num,
+%          numlist,
+%          numrange,
+%          of,
+%          pascal,
+%          per,
+%          percent,
+%          protected,
+%          radian,
+%          raiseto,
+%          robustify,
+%          second,
+%          SendSettingsToPgf,
+%          si,
+%          SI,
+%          sievert,
+%          SIlist,
+%          SIrange,
+%          sisetup,
+%          SIUnitSymbolDegree,
+%          square,
+%          squared,
+%          tesla,
+%          texorpdfstring,
+%          text,
+%          toprule,
+%          tothe,
+%          volt
+%        }
+%    }^^A 
+%}
+%\newcommand*\LaTeXdemo@input{^^A
+%  \MakePercentComment
+%  \catcode`\^^M=10\relax
+%  \small
+%  \begingroup
+%    \setkeys{lst}
+%      {
+%        SelectCharTable=\lst@ReplaceInput{\^\^I}{\lst@ProcessTabulator}
+%      }^^A
+%    \leavevmode 
+%      \input{\jobname.tmp}^^A
+%  \endgroup
+%  \MakePercentIgnore
+%}
+%\LaTeXdemo@new{code and example}
+%  {^^A
+%    \setbox\LaTeXdemo@box=\hbox\bgroup
+%      \lst@BeginAlsoWriteFile{\jobname.tmp}^^A
+%      \LaTeXdemo@common
+%  }
+%  {^^A
+%      \lst@EndWriteFile
+%    \egroup
+%    \begin{center}
+%      \ifdim\wd\LaTeXdemo@box>0.48\linewidth\relax
+%        \hbox to\linewidth{\box\LaTeXdemo@box\hss}^^A
+%          \begin{minipage}{\linewidth}
+%            \LaTeXdemo@input
+%          \end{minipage}
+%      \else
+%        \begin{minipage}{0.48\linewidth}
+%          \LaTeXdemo@input
+%        \end{minipage}
+%        \hfill
+%        \begin{minipage}{0.48\linewidth}
+%          \hbox to\linewidth{\box\LaTeXdemo@box\hss}^^A
+%        \end{minipage}
+%      \fi
+%    \end{center}
+%  }
+%\LaTeXdemo@new{code and float}{^^A
+%  \lst@BeginAlsoWriteFile{siunitx.tmp}^^A
+%  \LaTeXdemo@common
+%}{^^A
+%  \lst@EndWriteFile
+%  \LaTeXdemo@input
+%}
+%\LaTeXdemo@new{code only}
+%  {\LaTeXdemo@common}{}
+%  
+%^^A Turning of the marginpar warnings is a bit awkward.
+%^^A It is achieved by temporarily disabling \@latex@warning@no@line
+%\let\latex@addmarginpar\@addmarginpar
+%\let\latex@warning@no@line\@latex@warning@no@line
+%\def\@addmarginpar{^^A
+%  \let\@latex@warning@no@line\@gobble
+%  \latex@addmarginpar
+%  \let\@latex@warning@no@line\latex@warning@no@line
+%}
+%
+%\ProvideDocumentCommand\opt{m}{\texttt{#1}}
+%
+%\makeatother
 %
 %\GetFileInfo{\jobname.sty}
-%
-%\changes{v1.0}{2008/06/12}{First official release}
-%
-%\setkeys{lst}{language=[LaTeX]{TeX},moretexcs={sisetup,num,ang,SI,
-%  si,newunit,newpower,newprefix,metre,candela,kelvin,ampere,eV,
-%  second,mole,per,kilogram,Square,squared,cubed,cubic,kilo,centi,
-%  gram,tothe,toprule,midrule,bottomrule,newton,micro,joule,mega,
-%  raiseto,deci,mathnormal,numprint,electronvolt,selectlanguage,
-%  kibi,byte,molar,Molar,mmHg,mebi,torr,parsec,lightyear,clight,
-%  eVperc,addplot,color,milli,cm,Hz,kg,DeclareRobustCommand,
-%  pascal,dalton,addtolocale,DTLnewdb,DTLnewrow,DTLnewdbentry,
-%  DTLforeach,DTLiffirstrow,DTLmul,newqualifier,hour,renewunit,
-%  degree,numrange,SIrange}}
-%
-%\title{\currpkg\ --- A comprehensive (SI) units package^^A
-%  \thanks{This file describes version \fileversion, last revised
-%    \filedate.}}
-%\author{Joseph Wright^^A
-%  \thanks{E-mail: joseph.wright@morningstar2.co.uk}}
+% 
+%\title{^^A
+%  \textsf{siunitx} --- A comprehensive (SI) units package\thanks{^^A
+%    This file describes \fileversion, last revised \filedate.^^A
+%  }^^A
+%}
+%\author{^^A
+%  Joseph Wright\thanks{E-mail: joseph.wright@morningstar2.co.uk}^^A
+%}
 %\date{Released \filedate}
 %
 %\maketitle
 %
-%\newcommand*{\SIunits}{\pkg{SIunits}\xspace}
-%\newcommand*{\SIstyle}{\pkg{SIstyle}\xspace}
-%\newcommand*{\unitsdef}{\pkg{unitsdef}\xspace}
-%\newcommand*{\units}{\pkg{units}\xspace}
-%\newcommand*{\numprint}{\pkg{numprint}\xspace}
+%\changes{v0.6}{2008/02/18}{First public testing release (as \pkg{si})}
+%\changes{v1.0}{2008/06/15}{First official release}
+%\changes{v1.1}{2008/09/28}{Package extended to a greater range of unit
+%  types}
+%\changes{v1.2}{2009/01/22}{Correct handling for ranges of numbers 
+%  added}
+%\changes{v1.3}{2009/09/20}{Better definition for micro symbol}
+%\changes{v1.4}{2010/01/16}{Detect entire document in non-serif font}
+%\changes{v2.0}{2010/05/23}{Complete re-write of package to add many new
+%  features}
+%\changes{v2.0}{2010/05/23}{Introduced \cs{numlist} and \cs{SIlist}
+%  functions}
+%  
 %\begin{abstract}
 % Typesetting values with units requires care to ensure that the
 % combined mathematical meaning of the value plus unit combination is
@@ -198,2778 +412,2906 @@ This work consists of the file  siunitx.dtx
 % different countries and publishers have differing conventions on
 % the exact appearance of numbers (and units).
 %
-% The \currpkg provides a set of tools for authors to typeset numbers
-% and units in a consistent way.  The package has an extended set of
-% configuration options which make it possible to follow varying
-% typographic conventions with the same input syntax.  The package
-% includes automated processing of numbers and units, and the ability
-% to control tabular alignment of numbers.
-%
-% A number of \LaTeX\ packages have been developed in the past for
-% formatting units: \SIunits, \SIstyle, \unitsdef, \units,
-% \pkg{fancyunits} and \pkg{fancynum}. Support for users of all of
-% these packages is available as emulation modules in \currpkg.
-% In addition, \currpkg can carry out many of the functions of the
-% \pkg{dcolumn}, \pkg{rccol} and \numprint packages.
+% The \pkg{siunitx} package provides a set of tools for authors
+% to typeset numbers and units in a consistent way.  The package has an
+% extended set of configuration options which make it possible to 
+% follow varying typographic conventions with the same input syntax.  
+% The package includes automated processing of numbers and units, and
+% the ability to control tabular alignment of numbers.
 %\end{abstract}
 %
-%\begin{multicols}{2}
-%  \tableofcontents
-%\end{multicols}
+%\tableofcontents
+%
+%\begin{documentation}
+%
+%\section{Introduction}
 %
-%\clearpage
-%\part{Introduction}
 % The correct application of units of measurement is very important
 % in technical applications.  For this reason, carefully-crafted
 % definitions of a coherent units system have been laid down by the
-% \latin{Conf\'erence G\'en\'erale des Poids et
-% Mesures}\footnote{General Conference on Weights and Measures.}
-% (CGPM): this has resulted in the \latin{Syst\`eme International
-% d'Unit\'es}\footnote{International System of Units.} (SI).  At the
-% same time, typographic conventions for correctly displaying both
-% numbers and units exist to ensure that no loss of meaning occurs in
-% printed matter.
-%
-% \currpkg aims to provide a unified method for \LaTeX\ users to
+% \emph{Conf\'erence G\'en\'erale des Poids et
+% Mesures} (CGPM): this has resulted in the \emph{Syst\`eme 
+% International d'Unit\'es} (SI).  At the same time, typographic 
+% conventions for correctly displaying both numbers and units exist to
+% ensure that no loss of meaning occurs in printed matter.
+%
+% \pkg{siunitx} aims to provide a unified method for LaTeX users to
 % typeset units and values correctly and easily.  The design
-% philosophy of \currpkg is to follow the agreed rules by default,
-% but to allow variation through option settings.  In this way,
-% users can use \currpkg to follow the requirements of publishers,
-% co-authors, universities, \etc without needing to alter the input
-% at all.
-%
-% \currpkg is intended as a complete replacement for \SIunits,
-% \SIstyle, \unitsdef, \units, \pkg{fancyunits} and
-% \pkg{fancynum}. As such, emulation modes are provided for all of
-% these packages.  Where possible, conventions from the existing
-% solutions have been used here.  For example, the macros \cs{num},
-% \cs{ang} and \cs{SI} act in a very similar fashion to those in
-% existing packages.
-%
-%\clearpage
-%\part{Using the \currpkg package}
-%
-%\section{For the impatient}
-% \currpkg provides the user macros:
+% philosophy of \pkg{siunitx} is to follow the agreed rules by 
+% default, but to allow variation through option settings.  In this way,
+% users can use \pkg{siunitx} to follow the requirements of 
+% publishers, co-authors, universities, \emph{etc}.~without needing to 
+% alter the input at all.
+% 
+%\section{Installation}
+%
+% The package is supplied in \file{dtx} format and as a pre-extracted
+% zip file, \file{\jobname.tds.zip}. The later is most convenient for
+% most users: simply unzip this in your local texmf directory and
+% run \texttt{texhash} to update the database of file locations. If
+% you want to unpack the \file{dtx} yourself, running 
+% \texttt{tex \jobname.dtx} will extract the package whereas
+% \texttt{latex \jobname.dtx} will extract it and also typeset the
+% documentation.
+%
+% The package requires LaTeX3 support as provided in the 
+% \pkg{expl3} and \pkg{xpackages} bundles. Both of these are available
+% on \href{http://www.ctan.org}{\textsc{ctan}} as ready-to-install
+% zip files. Suitable versions are available in MiKTeX 2.8 and
+% TeX Live 2009 (updating the relevant packages online may be
+% necessary). LaTeX3, and so \pkg{siunitx}, requires the e-TeX 
+% extensions: these are available on all modern TeX systems.
+% 
+% Typesetting the documentation requires a number of packages in
+% addition to those needed to use the package. This is mainly 
+% because of the number of demonstration items included in the text. To
+% compile the documentation without error, you will need the packages:
+%\begin{itemize} 
+% \item \pkg{amsmath}
+% \item \pkg{booktabs}
+% \item \pkg{caption}
+% \item \pkg{cleveref}
+% \item \pkg{csquotes}
+% \item \pkg{helvet}
+% \item \pkg{mathpazo}
+% \item \pkg{listings}
+% \item \pkg{pgfplots}
+% \item \pkg{xcolor}
+%\end{itemize}
+% The \pkg{xfrac} package is also loaded if available, but is not 
+% required to typeset the documentation.
+% 
+%\section{\pkg{siunitx} for the impatient}
+%
+% The package provides the user macros:
 %\begin{itemize}
-%  \item \cs{SI}\oarg{options}\marg{value}\oarg{pre-unit}\marg{unit}
-%  \item \cs{si}\oarg{options}\marg{unit}
 %  \item \cs{num}\oarg{options}\marg{number}
+%  \item \cs{si}\oarg{options}\marg{unit}
+%  \item \cs{SI}\oarg{options}\marg{value}\oarg{pre-unit}\marg{unit}
+%  \item \cs{numlist}\oarg{options}\marg{numbers}
+%  \item \cs{numrange}\oarg{options}\marg{numbers}\marg{number2}
+%  \item \cs{SIlist}\oarg{options}\marg{numbers}\marg{unit}
+%  \item \cs{SIrange}\oarg{options}\marg{number1}\marg{number2}^^A
+%    \marg{unit}
 %  \item \cs{ang}\oarg{options}\marg{angle}
 %  \item \cs{sisetup}\marg{options}
 %\end{itemize}
-% plus the |S| and |s| column types for decimal alignments and units
-% in tables.  These macros are designed for typesetting units and
-% values with control of appearance and with intelligent processing.
-%
-% By default, all text is typeset in the current upright, serif maths
-% font.  This can be changed by setting the appropriate package
-% options: \opt{obeyall} will use the current font for typesetting.
-%
-% The package includes a ``unit processor'', which allows the use of
-% named units or literal values.  Named units are processed to
-% correctly include powers.
-%\begin{LaTeXexample}
-%  \SI{10}{\gram}\\
-%  \SI{23.4}{g.cm^3}\\
-%  \num{1e34}\\
-%  \ang{1;2;3}\\
-%  \emph{\SI{16,7}{\metre\per\second}}\\
-%  \textbf{\SI{30e3}{\Hz}}\\
-%  \SI{1.2 x 3.56 x 9.2}{\milli\metre}\\
-%  \sisetup{obeyall}
-%  \textbf{\SI{-4.5}{\cm}}\\
-%  \si{\joule\per\mole\per\kelvin}\\
-%  \si[per=frac]{\joule\per\mole\per\kelvin}\\
-%  \num[dp=4]{1.23456}\\
-%  \num[dp=4]{9.8}\\
-%  \begin{tabular}{S[tabformat=3.2]}
+% plus the \texttt{S} and \texttt{s} column types for decimal 
+% alignments and units in tables.  These macros are designed for 
+% typesetting units and values with control of appearance and with 
+% intelligent processing.
+% 
+% Numbers are processed with understanding of exponents, complex numbers
+% and multiplication.
+%\begin{LaTeXdemo}
+%  \num{12345,67890} \\
+%  \num{1+-2i}       \\
+%  \num{.3e45}       \\
+%  \num{1.654 x 2.34 x 3.430}
+%\end{LaTeXdemo} 
+%
+% The unit  system can interpret units given as text to be used directly
+% or as macro-based units. In the later case, different formatting is
+% possible.
+%\begin{LaTeXdemo}
+%  \si{kg.m.s^{-1}}                \\
+%  \si{\kilogram\metre\per\second} \\
+%  \si[per-mode=symbol]
+%    {\kilogram\metre\per\second}  \\
+%  \si[per-mode=symbol]
+%    {\kilogram\metre\per\ampere\per\second}      
+%\end{LaTeXdemo}
+%
+% Simple lists and ranges of numbers can be handled.
+%\begin{LaTeXdemo}
+%  \numlist{10;20;30}                    \\
+%  \SIlist{0.13;0.67;0.80}{\milli\metre} \\
+%  \numrange{10}{20}                     \\
+%  \SIrange{0.13}{0.67}{\milli\metre}
+%\end{LaTeXdemo}
+% 
+% By default, all text is typeset in the current upright, serif math
+% font.  This can be changed by setting the appropriate options: 
+% "\sisetup{detect-all}" will use the current font for typesetting.
+% 
+%\section{Using the \pkg{siunitx} package}
+%
+%\subsection{Loading the package}
+%
+% The package should be loaded in the usual LaTeX2e way.
+%\begin{LaTeXdemo}[code only]
+%  \usepackage{siunitx}
+%\end{LaTeXdemo} 
+% The key--value options described later in this document can be used
+% when loading the package, for example
+%\begin{LaTeXdemo}[code only]
+%  \usepackage[load-configuration = version-1]{siunitx}
+%\end{LaTeXdemo} 
+% to use options from version 1 of the package.
+%
+%\subsection{Numbers}
+%
+%\DescribeMacro{\num}
+%\begin{syntax}
+%  \cs{num}\oarg{options}\marg{number}
+%\end{syntax}
+% Numbers are automatically formatted by the \cs{num} macro.  This
+% takes one optional argument, \meta{options}, and one mandatory one,
+% \meta{number}.  The contents of \meta{number} are automatically 
+% formatted.  The formatter removes \enquote{hard} spaces 
+% (\cs{,} and "~"), automatically identifies exponents (by default 
+% marked using \texttt{e}, \texttt{E}, \texttt{d} or \texttt{D}) and 
+% adds the appropriate spacing of large numbers.  With the standard
+% settings a leading zero is added before a decimal marker, if needed: 
+% both \enquote{\texttt{.}} and \enquote{\texttt{,}} are recognised as 
+% decimal markers.
+%\begin{LaTeXdemo}
+%  \num{123}     \\
+%  \num{1234}    \\
+%  \num{12345}   \\
+%  \num{0.123}   \\
+%  \num{0,1234}  \\
+%  \num{.12345}  \\
+%  \num{3.45d-4} \\
+%  \num{-e10}
+%\end{LaTeXdemo}
+% Note that numbers are parsed before typesetting, which does 
+% have a performance overhead (only obvious with very large amounts
+% of numerical input). The parser understands a range of input syntaxes,
+% as demonstrated above.
+% 
+%\DescribeMacro{\numlist}
+%\begin{syntax}
+%  \cs{numlist}\oarg{options}\marg{numbers}
+%\end{syntax}
+% Lists of numbers may be processed using the \cs{numlist} function.
+% Each \meta{number} is given within the list of \meta{numbers} within
+% a brace pair, as the list can have a flexible length.
+%\begin{LaTeXdemo}
+%  \numlist{10;30;50;70}
+%\end{LaTeXdemo}
+%
+%\DescribeMacro{\numrange}
+%\begin{syntax}
+%  \cs{numrange}\oarg{options}\marg{number1}\marg{number2}
+%\end{syntax}
+% Simple ranges of numbers can be handled using the \cs{numrange}
+% function. This acts in the same way as \cs{num}, but inserts a 
+% phrase or other text between the two entries. 
+%\begin{LaTeXdemo}
+%  \numrange{10}{30}
+%\end{LaTeXdemo}
+%
+%\DescribeMacro{\ang}
+%\begin{syntax}
+%  \cs{ang}\oarg{options}\marg{angle}
+%\end{syntax}
+% Angles can be typeset using the \cs{ang} command.  The
+% \meta{angle} can be given either as a decimal number or as a
+% semi-colon separated list of degrees, minutes and seconds, which 
+% is called \enquote{arc format} in this document. The numbers which 
+% make up an angle are processed using the same system as other numbers.
+%\begin{LaTeXdemo}
+%  \ang{10}    \\
+%  \ang{12.3}  \\
+%  \ang{4,5}   \\
+%  \ang{1;2;3} \\
+%  \ang{;;1}   \\
+%  \ang{+10;;} \\
+%  \ang{-0;1;}
+%\end{LaTeXdemo}
+%
+%\subsection{Units}
+%
+%\DescribeMacro{\si}
+%\begin{syntax}
+%  \cs{si}\oarg{options}\marg{unit}
+%\end{syntax}
+% The symbol for a unit can be typeset using the \cs{si} macro: this 
+% provides full control over output format for the unit. Like the
+% \cs{num} macro, \cs{si} takes  one optional and one mandatory 
+% argument. The unit formatting system can accept two types of input. 
+% When the \meta{unit} contains literal items (for example letters or
+% numbers) then \pkg{siunitx} converts \texttt{.} and "~" into
+% inter-unit separators and correctly positions sub- and superscripts
+% specified using "_" and "^". The formatting methods will work with
+% both math and text mode.
+%\begin{LaTeXdemo}
+%  \si{kg.m/s^2} \\
+%  \si{g_{polymer}~mol_{cat}.s^{-1}}
+%\end{LaTeXdemo}
+% The second operation mode for the \cs{si} macro is an 
+% \enquote{interpreted} system, Here, each unit, SI multiple prefix and 
+% power is given a macro name.  These are entered in a method very 
+% similar to the reading of the unit name in English.
+%\begin{LaTeXdemo}
+%  \si{\kilo\gram\metre\per\square\second} \\
+%  \si{\gram\per\cubic\centi\metre}        \\
+%  \si{\square\volt\cubic\lumen\per\farad} \\
+%  \si{\metre\squared\per\gray\cubic\lux}  \\
+%  \si{\henry\second}                      
+%\end{LaTeXdemo}
+% On its own, this is less convenient than the direct method, although
+% it does use meaning rather than appearance for input. However, the
+% package allows you to define new unit macros; a large number of
+% pre-defined abbreviations are also supplied.  More importantly, by
+% defining macros for units, instead of literal values, new
+% functionality is made available.  By altering the settings used by the
+% package, the same input can yield a variety of different output 
+% formats. For example, the \cs{per} macro can give reciprocal powers,
+% slashes or be used to construct units as fractions.
+%
+%\DescribeMacro{\SI}
+%\begin{syntax}
+%  \cs{SI}\oarg{options}\marg{number}\oarg{preunit}\marg{unit}
+%\end{syntax}
+% Very often, numbers and values are given together. Mathematically, 
+% these form a single entity, and should be separated by a non-breaking
+% space. The \cs{SI} macro combines the functionality of \cs{num} and
+% \cs{si}, and makes this both possible and easy. The \meta{number} and 
+% \meta{unit} arguments work exactly like those for the \cs{num} and 
+% \cs{si} macros, respectively. \meta{preunit} is a unit to be typeset 
+% \emph{before} the numerical value (most likely to be a currency).
+%\begin{LaTeXdemo}
+%  \SI[mode=text]{1.23}{J.mol^{-1}.K^{-1}}          \\
+%  \SI{.23e7}{\candela}                             \\
+%  \SI[per-mode=symbol]{1.99}[\$]{\per\kilogram}    \\
+%  \SI[per-mode=fraction]{1,345}{\coulomb\per\mole}
+%\end{LaTeXdemo}
+%
+% It is possible to set up the unit macros to be available outside of
+% the \cs{SI} and \cs{si} functions. This is not the standard behaviour
+% as there is the risk of name clashes (for example, \cs{bar} is used
+% by other packages, and several packages define \cs{degree}). Full
+% details of using \enquote{stand alone} units are found in 
+% \cref{sec:units:creating}.
+% 
+%\DescribeMacro{\SIlist}
+%\begin{syntax}
+%  \cs{SIlist}\oarg{options}\marg{numbers}\marg{unit} 
+%\end{syntax}
+% Lists of numbers with units can be handled using the \cs{SIlist}
+% function. The behaviour of this function is similar to \cs{numlist},
+% but with the addition of a unit to each number.
+%\begin{LaTeXdemo}
+%  \SIlist{10;30;45}{\metre}
+%\end{LaTeXdemo}
+% 
+%\DescribeMacro{\SIrange}
+%\begin{syntax}
+%  \cs{SIrange}\oarg{options}\marg{number1}\marg{number2}\marg{unit} 
+%\end{syntax}
+% Ranges of numbers with units can be handled using the \cs{SIrange}
+% function. The behaviour of this function is similar to \cs{numrange},
+% but with the addition of a unit to each number.
+%\begin{LaTeXdemo}
+%  \SIrange{10}{30}{\metre}
+%\end{LaTeXdemo}
+%
+%\subsection{The unit macros}
+%
+% The package always defines the basic set of SI units with macro names.
+% This includes the base SI units, the derived units with special names
+% and the prefixes. A small number of powers are also given pre-defined
+% names. Full details of units in the SI are available 
+% on-line~\cite{BIPM}.
+% 
+%\DescribeMacro{\meter}
+% The seven base SI units are always defined 
+% (\cref{tab:unit:base}). In addition, the macro \cs{meter} is
+% available as an alias for \cs{metre}, for users of US spellings.
+% The full details of the base units are given in the SI 
+% Brochure~\cite{SI:2.1}.
+%\begin{table}
+%  \caption{SI base units.}
+%  \label{tab:unit:base}
+%  \centering
+%  \begin{tabular}{lll}
 %    \toprule
-%    {Heading}\\
+%     Unit & Macro & Symbol \\
 %    \midrule
-%    1.3 \\
-%    134.2 \\
-%    3.56 \\
-%    74,7 \\
+%      \DescribeUnit{ampere}   \\
+%      \DescribeUnit{candela}  \\
+%      \DescribeUnit{kelvin}   \\
+%      \DescribeUnit{kilogram} \\ 
+%      \DescribeUnit{metre}    \\
+%      \DescribeUnit{mole}     \\
+%      \DescribeUnit{second}   \\ 
 %    \bottomrule
 %  \end{tabular}
-%\end{LaTeXexample}
-%
-%\section{Requirements}
-% \currpkg requires a reasonably up to date \TeX\ system.  The
-% package requires \eTeX-extensions, which should be available on
-% most systems.\footnote{If you have an old \LaTeX\, try
-% ``\texttt{elatex}'' rather than ``\texttt{latex}''.}  The following
-% packages are also needed:
-%\begin{itemize}
-%  \item \pkg{array} and \pkg{xspace}: from the \pkg{tools} bundle,
-%    which should be available to everyone;
-%  \item \pkg{xkeyval}: this processes the option handling, and needs
-%    to be at least v2.5;
-%  \item \pkg{amstext}: from the \AMS\TeX\ support bundle (the
-%    \AMS\ fonts are also needed to provide the default upright
-%    \si{\micro}).
-%\end{itemize}
-% Hopefully most people using the package will have access to all of
-% those items.
-%
-% To use the \opt{fraction=sfrac} option, the \pkg{xfrac} package is
-% needed.  This needs various experimental \LaTeX3 packages.  As a
-% result, \currpkg does not load \pkg{xfrac}.  If you want to use
-% \opt{fraction=sfrac}, \emph{you} need to load \pkg{xfrac} in your
-% preamble before \currpkg.\footnote{This document has been compiled
-% in this way.  You have to load \pkg{xfrac} first as otherwise very
-% nasty things happen with \pkg{xkeyval}.  MiK\TeX\ users should note
-% that the packaged versions of \pkg{expl3}, \pkg{template} and
-% \pkg{xparse} will not work with \pkg{xfrac}: download copies from
-% \textsc{ctan}!} If the package is not loaded, \opt{fraction=sfrac}
-% falls back on a \pkg{nicefrac}-like method.  The interested user
-% should look at the \pkg{xfrac} documentation for reasons this might
-% not be ideal.\footnote{On the other hand, some fractional units
-% will look really bad with \cs{sfrac}.  Use this option with
-% caution.}
-%
-%\section{Loading the package}
-% \currpkg is loaded by the usual \LaTeX\ method.
-%\begin{LaTeXexample}[noexample]
-%  \usepackage[<options>]{siunitx}
-%\end{LaTeXexample}
-% As is shown in the example, the package can be loaded with one or
-% more options, using the key--value system.  The full range of
-% package options are described in Section~\ref{sec:options}; some
-% options are described in the along with the appropriate user
-% macros.  Most of the user macros accept the same key--value
-% settings as an optional argument.
-%
-%\section{Numbers}
-%\DescribeMacro{\num}
-% Numbers are automatically formatted by the \cs{num} macro.  This
-% takes one optional and one mandatory argument:
-% \cs{num}\oarg{options}\marg{number}.  The contents of \meta{number}
-% are automatically formatted, in a similar method to that used by
-% \numprint.  The formatter removes ``hard'' spaces (\cs{,} and |~|),
-% automatically identifies exponents (by default marked using |e| or
-% |d|) and adds the appropriate spacing of large numbers.  A leading
-% zero is added before a decimal marker, if needed: both ``|.|'' and
-% ``|,|'' are recognised as decimal marker.
-%\begin{LaTeXexample}
-%  \num{1}    \num{123}     \num{1234}  \num{12345}\\
-%  \num{0.1}  \num{0.123}   \num{0,1234} \num{.12345}\\
-%  \num{1e10} \num{3.45d-4} \num{-e10}
-%\end{LaTeXexample}
-% Various error-checking systems are built into the package, so that
-% if \meta{number} does not contain any numeric characters, a warning
-% is issued.  Isolated signs are also detected.  The package
-% recognises |(| and |)| as ``extra'' characters, which can be used
-% to indicate the error in a number.\footnote{This is common in
-% chemical crystallography, for example.}  The \opt{seperr} causes
-% this data to be given as a separate error value.  If the number
-% also contains an exponent, then brackets are re-added after the
-% separation to ensure that meaning is not lost.
-%\begin{LaTeXexample}
-%  $\num{1.234(5)} = \num[seperr]{1.234(5)}$\\
-%  $\num{1.234(5)e6} = \num[seperr]{1.234(5)e6}$
-%\end{LaTeXexample}
-% The same applies to the unit and value macro \cs{SI}, described
-% later, for example the rest mass of an electron \cite{IUPAC}:
-%\begin{LaTeXexample}
-%   $ m_{\mathrm{e}}
-%     = \SI{9.1093897(54)e-31}{\kg} $\\
-%   $ m_{\mathrm{e}}
-%     = \SI[seperr]{9.1093897(54)e-31}{\kg} $
-%\end{LaTeXexample}
-%
-% A number of effects are available as options.  These are fully
-% explained in Section~\ref{sec:options}.  Some of the more useful
-% options are illustrated here.  By default, the output of the
-% package is typeset in maths mode.  However, the use of the current
-% text font can be forced.\footnote{This document is typeset using
-% lowercase numbers in text mode, which emphasises the effect here.}
-%\begin{LaTeXexample}
-%  \num{1234567890} \num[mode=text]{1234567890}
-%\end{LaTeXexample}
-% \currpkg can automatically add zeros and signs to numbers.  This
-% can be altered as desired.
-%\begin{LaTeXexample}
-%  \num{1.}  \num[padnumber=all]{1.}\\
-%  \num{2}   \num[addsign=all]{2}\\
-%  \num{3e4} \num[addsign=mant]{3e4} \num[addsign=all]{3e4}\\
-%  \num{.5}  \num[padnumber=none]{.5}
-%\end{LaTeXexample}
-% The separation of digits can be turned on and off, and the output
-% changed.
-%\begin{LaTeXexample}
-%  \num{1234}  \num[sepfour=true]{1234}\\
-%  \num{12345} \num[digitsep=comma]{12345}\\
-%  \num[digitsep=none]{12345}
-%\end{LaTeXexample}
-% The formatting of exponents is also customisable.
-%\begin{LaTeXexample}
-%  \num{1e10} \num[expproduct=cdot]{1e10}\\
-%  \num{2e20} \num[expbase=5]{2e20}\\
-%  \num{3e30} \num[expproduct=tighttimes]{3e30}
-%\end{LaTeXexample}
-%
-% \currpkg can automatically add colour to negative numbers, which is
-% often useful for highlighting purposes.  This is turned on with the
-% \opt{colourneg} option; the colour used is set by \opt{negcolour}.
-% Both of these are available with the US spellings: \opt{colorneg}
-% and \opt{negcolor}.
-%\begin{LaTeXexample}
-%  \num{-1}\\
-%  \sisetup{colourneg} \num{-2}\\
-%  \num{3e-3}\\
-%  \num[negcolour=blue]{-4}
-%\end{LaTeXexample}
-%
-% \currpkg can automatically zero-fill and round to a fixed number of
-% decimal places.  This is controlled by two options \opt{fixdp} and
-% \opt{dp}.  The later is an integer which specifies how many places
-% to fix to; setting this option automatically sets \opt{fixdp} to
-% \opt{true}.  The place-fixing system will only alter pure numbers: for
-% example, any error component will result in the input being left
-% unchanged.
-%\begin{LaTeXexample}
-%  \num{1.23456}\\
-%  \sisetup{dp=2}
-%  \num{1.23456}\\
-%  \num{9.8}\\
-%  \num{-10.432}\\
-%  \num{44.3221(2)}
-%\end{LaTeXexample}
-%
-%\section{Tabular material}
-%\subsection{Aligning numbers}
-% Centring numbers in tabular content is handled by a new column
-% type, the |S| column.  This is based closely on the \pkg{dcolumn}
-% method for centring numbers in columns, but adds the functionality
-% of the \cs{num} macro.\footnote{The approach used is actually a
-% combination of \pkg{dcolumn} for centring the material and
-% \numprint for processing it.  It will therefore give rather
-% different results than the \texttt{n} and \texttt{N} column types
-% in \numprint.}
-%
-% By default, the decimal marker of the number is placed at the
-% centre of the column, which then resizes to accommodate the width
-% of the contents (\ref{tab:default}).  This behaviour is set by the
-% \opt{tabnumalign=centredecimal} option.  By setting the
-% \opt{tabnumalign} option to \opt{centre}, the centre of the space
-% reserved for the number is placed at the centre of the column.  The
-% space reserved is stored in \opt{tabformat}, which is of the form
-% \texttt{\meta{before}\meta{dec}\meta{after}}, where \meta{before}
-% is the number of characters before the decimal marker and
-% \meta{after} is the number after. Thus in the example,
-% \opt{tabformat=2.4} provides space for two digits before the
-% decimal marker and four after.  \opt{tabnumalign} can also be set
-% to \opt{left} and \opt{right}, with the expected results.
-%\begin{LaTeXexample}[float]
+%\end{table}
+%
+%\DescribeMacro{\celsius}
+% The SI also lists a number of units which have special names and 
+% symbols \cite{SI:2.2.2}: these are listed in 
+% \cref{tab:unit:derived}. As a short-cut for the degree Celsius,
+% the unit \cs{celsius} is defined equivalent to \cs{degreeCelsius} .
+%\begin{table}
+%  \caption{Coherent derived units in the SI with special names and 
+%    symbols.}
+%  \label{tab:unit:derived}
+%  \centering
+%  \begin{tabular}{lll>{\qquad}lll}
+%    \toprule
+%      Unit & Macro & Symbol & Unit & Macro & Symbol \\
+%    \midrule
+%      \DescribeUnit{becquerel} &
+%      \DescribeUnit{newton}    \\ 
+%      \DescribeNamedUnit{degree Celsius}{degreeCelsius} &
+%      \DescribeUnit{ohm}       \\
+%      \DescribeUnit{coulomb}   &
+%      \DescribeUnit{pascal}    \\
+%      \DescribeUnit{farad}     &
+%      \DescribeUnit{radian}    \\
+%      \DescribeUnit{gray}      &
+%      \DescribeUnit{siemens}   \\
+%      \DescribeUnit{hertz}     &
+%      \DescribeUnit{sievert}   \\
+%      \DescribeUnit{henry}     &
+%      \DescribeUnit{steradian} \\
+%      \DescribeUnit{joule}     &
+%      \DescribeUnit{tesla}     \\
+%      \DescribeUnit{katal}     &
+%      \DescribeUnit{volt}      \\
+%      \DescribeUnit{lumen}     &
+%      \DescribeUnit{watt}      \\
+%      \DescribeUnit{lux}       &
+%      \DescribeUnit{weber}     \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+% In addition to the official SI units, \pkg{siunitx} also provides
+% macros for a number of units which are accepted for use in the SI
+% although they are not SI units. \cref{tab:unit:accepted} lists 
+% the \enquote{accepted} units \cite{SI:4.1.T6}. Some units are 
+% fundamental physical quantities, and these are non-SI but can be used 
+% within the SI (\cref{tab:unit:physical}, \cite{SI:4.1.T7}). 
+% There are also a set of non-SI units which are used in certain 
+% defined circumstances (\cref{tab:unit:other}), although they are 
+% not necessarily official sanctioned \cite{SI:4.1.T8}.
+%\begin{table}
+%  \caption{Non-SI units accepted for use with the 
+%    International System of Units.}
+%  \label{tab:unit:accepted}
+%  \centering
+%  \begin{tabular}{lll}
+%    \toprule
+%      Unit & Macro & Symbol \\
+%    \midrule
+%      \DescribeUnit{day}     \\
+%      \DescribeUnit{degree}  \\
+%      \DescribeUnit{hectare} \\
+%      \DescribeUnit{hour}    \\
+%      \DescribeUnit{litre}   \\
+%        \SpecialUsageIndex{\liter}^^A 
+%       & \cs{liter} & \si{\liter} \\
+%      \DescribeNamedUnit{minute (plane angle)}{arcminute} \\ 
+%      \DescribeNamedUnit{minute (time)}{minute} \\
+%      \DescribeNamedUnit{second (plane angle)}{arcsecond} \\ 
+%      \DescribeUnit{tonne}   \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%\begin{table}
+%  \caption{Non-SI units whose values in SI units must be obtained 
+%    experimentally.}
+%  \label{tab:unit:physical}
+%  \centering
+%  \begin{tabular}{lll}
+%    \toprule
+%      Unit & Macro & Symbol \\
+%    \midrule
+%      \DescribeNamedUnit{astronomical unit}{astronomicalunit} \\
+%      \DescribeNamedUnit{atomic mass unit}{atomicmassunit} \\
+%      \DescribeUnit{bohr}         \\
+%      \DescribeNamedUnit{speed of light}{clight} \\
+%      \DescribeUnit{dalton}       \\
+%      \DescribeNamedUnit{electron mass}{electronmass} \\
+%      \DescribeUnit{electronvolt} \\
+%      \DescribeNamedUnit{elementary charge}{elementarycharge} \\
+%      \DescribeUnit{hartree} \\
+%      \DescribeNamedUnit{reduced Planck constant}{planckbar} \\ 
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%\begin{table}
+%  \caption{Other non-SI units.}
+%  \label{tab:unit:other}
+%  \centering
+%  \begin{tabular}{lll}
+%    \toprule
+%      Unit & Macro & Symbol  \\
+%    \midrule
+%      \DescribeNamedUnit{{\aa}ngstr{\"o}m}{angstrom} \\
+%      \DescribeUnit{bar}  \\
+%      \DescribeUnit{barn} \\
+%      \DescribeUnit{bel}  \\
+%      \DescribeUnit{decibel} \\
+%      \DescribeUnit{knot} \\
+%      \DescribeNamedUnit{millimetre of mercury}{mmHg} \\
+%      \DescribeNamedUnit{nautical mile}{nauticalmile} \\ 
+%      \DescribeUnit{neper} \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+%\DescribeMacro{\deka}
+% In addition to the units themselves, \pkg{siunitx} provides 
+% pre-defined macros for all of the SI prefixes 
+% (\cref{tab:unit:prefix}, \cite{SI:3.1}). The spelling
+% \enquote{\cs{deka}} is provided for US users as an alternative to 
+% \cs{deca}.
+%\begin{table}
+%  \caption{SI prefixes.}
+%  \label{tab:unit:prefix}
+%  \centering
+%  \begin{tabular}{llc>{$}l<{$}>{\qquad}llc>{$}l<{$}}
+%    \toprule
+%      Prefix & Macro & Symbol & \multicolumn{1}{l}{Power} & 
+%        Prefix & Macro & Symbol & \multicolumn{1}{l}{Power} \\
+%    \midrule
+%      \DescribePrefix{yocto} & -24 &
+%      \DescribePrefix{deca}  &   1 \\
+%      \DescribePrefix{zepto} & -21 &
+%      \DescribePrefix{hecto} &   2 \\
+%      \DescribePrefix{atto}  & -18 &
+%      \DescribePrefix{kilo}  &   3 \\
+%      \DescribePrefix{femto} & -15 &
+%      \DescribePrefix{mega}  &   6 \\
+%      \DescribePrefix{pico}  & -12 &
+%      \DescribePrefix{giga}  &  9 \\
+%      \DescribePrefix{nano}  &  -9 &
+%      \DescribePrefix{tera}  &  12 \\
+%      \DescribePrefix{micro} & -6 &
+%      \DescribePrefix{peta}  &  15 \\
+%      \DescribePrefix{milli} &  -3 &
+%      \DescribePrefix{exa}   &  18 \\
+%      \DescribePrefix{centi} &  -2 &
+%      \DescribePrefix{zetta} &  21 \\
+%      \DescribePrefix{deci}  &  -1 &
+%      \DescribePrefix{yotta} &  24 \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+%\DescribeMacro{\square}
+%\DescribeMacro{\squared}
+%\DescribeMacro{\cubic}
+%\DescribeMacro{\cubed}
+% A small number of pre-defined powers are provided as macros. 
+% \cs{square} and \cs{cubic} are intended for use before units, with
+% \cs{squared} and \cs{cubed} going after the unit.
+%\begin{LaTeXdemo} 
+%  \si{\square\becquerel} \\
+%  \si{\joule\squared\per\lumen} \\
+%  \si{\cubic\lux\volt\tesla\cubed}
+%\end{LaTeXdemo}
+%\DescribeMacro{\tothe}
+%\DescribeMacro{\raiseto}
+% Generic powers can be inserted on a one-off basis using the \cs{tothe}
+% and \cs{raiseto} macros. These are the only macros for units which
+% take an argument:
+%\begin{LaTeXdemo} 
+%  \si{\henry\tothe{5}} \\
+%  \si{\raiseto{4.5}\radian}
+%\end{LaTeXdemo}
+%\DescribeMacro{\per}
+% Reciprocal powers are indicated using the \cs{per} macro. This applies
+% to the next unit only, unless the \opt{sticky-per} option
+% is turned on.
+%\begin{LaTeXdemo} 
+%  \si{\joule\per\mole\per\kelvin} \\
+%  \si{\joule\per\mole\kelvin} \\
+%  \si{\per\henry\tothe{5}} \\
+%  \si{\per\square\becquerel} 
+%\end{LaTeXdemo}
+%\DescribeMacro{\of}
+% As for generic powers, generic qualifiers are also available using
+% the \cs{of} function:
+%\begin{LaTeXdemo} 
+%  \si{\kilogram\of{metal}} \\
+%  \SI[qualifier-mode = brackets]
+%    {0.1}{\milli\mole\of{cat}\per\kilogram\of{prod}}
+%\end{LaTeXdemo}
+%
+% When using the unit macros, the package is able to validate the
+% input given. As part of this, stand-alone unit prefixes can be used
+% with the \cs{si} macro
+%\begin{LaTeXdemo} 
+%  \si{\kilo} \\
+%  \si{\micro}
+%\end{LaTeXdemo}
+% However, the package only allows a single prefix to be used in this
+% way: multiple prefixes will give an error, as will trying to give 
+% a number without a unit. So the following will raise errors:
+%\begin{LaTeXdemo}[code only] 
+%  \si{\kilo\gram\micro} \\
+%  \SI{10}{\micro}
+%\end{LaTeXdemo}
+% 
+%\subsection{Creating new macros}
+%
+% The various macro components of a unit have to be defined before
+% they can be used. The package supplies a number of common definitions,
+% but new definitions are also possible. As the definition of a logical
+% unit should remain the same in a single document, these creation
+% functions are all preamble-only. 
+%
+%\DescribeMacro{\DeclareSIUnit}
+%\DescribeMacro{\DeclareSIUnitWithOptions}
+%\begin{syntax}
+%  \cs{DeclareSIUnit}\marg{unit}\marg{symbol}
+%  \cs{DeclareSIUnitWithOptions}\marg{unit}\marg{symbol}\marg{options}
+%\end{syntax}
+% New units are produced using the \cs{DeclareSIUnit} macro. 
+% \meta{symbol} can contain literal values, other units, multiple
+% prefixes, powers and \cs{per}, although literal text should not be
+% intermixed with unit macros. Units can be created with options
+% using the \cs{DeclareSIUnitWithOptions} function, where the 
+% \meta{options} argument can be any suitable options, and applies the
+% specific unit macro only. The (first) optional argument to \cs{SI} 
+% and \cs{si} can be used to override the settings for the unit. A 
+% typical example is the \cs{degree} unit.
+%\begin{LaTeXdemo}
+%  \SI{3.1415}{\degree}
+%\end{LaTeXdemo} 
+% This is declared in the package as:
+%\begin{LaTeXdemo}[code only]
+%  \DeclareSIUnitWithOptions\degree{\SIUnitSymbolDegree}
+%    {number-unit-separator={}}
+%\end{LaTeXdemo}
+% The spacing can still be altered at point of use:
+%\begin{LaTeXdemo}
+%  \SI{67890}{\degree} \\
+%  \SI[number-unit-separator = \;]{67890}{\degree}
+%\end{LaTeXdemo}
+% The meaning of a pre-defined unit can be altered by using
+% \cs{DeclareSIUnit} after loading \pkg{siunitx}. This will overwrite
+% the original definition with the newer version.
+% 
+%\DescribeMacro{\DeclareSIPrefix}
+%\DescribeMacro{\DeclareBinaryPrefix}
+%\begin{syntax}
+%  \cs{DeclareSIPrefix}\marg{prefix}\marg{symbol}\marg{powers-ten}
+%  \cs{DeclareBinaryPrefix}\marg{prefix}\marg{symbol}\marg{powers-two}
+%\end{syntax}
+% The standard SI powers of ten are defined by the package, and are
+% described above.  However, the user can define new prefixes with
+% \cs{DeclareSIPrefix}. The \cs{DeclareBinaryPrefix} function is also
+% available for creating binary prefixes, with the same syntax 
+% (\meta{powers-ten} being replaced by \meta{powers-two}). For 
+% example, \cs{kilo} and \cs{kibi} are defined:
+%\begin{LaTeXdemo}[code only]
+%  \DeclareSIPrefix\kilo{k}{3}
+%  \DeclareBinaryPrefix\kibi{Ki}{10}
+%\end{LaTeXdemo}
+%
+%\DescribeMacro{\DeclareSIPostPower}
+%\DescribeMacro{\DeclareSIPrePower}
+%\begin{syntax}
+%  \cs{DeclareSIPostPower}\marg{power}\marg{num}
+%  \cs{DeclareSIPrePower}\marg{power}\marg{num}
+%\end{syntax}
+% These create power macros to appear before or after the unit they
+% apply to. For example, the preamble to a document might contain:
+%\begin{LaTeXdemo}[code only]
+%  \DeclareSIPrePower\quartic{4}
+%  \DeclareSIPostPower\tothefourth{4}
+%\end{LaTeXdemo}
+% with the functions then used in the document as:
+%\begin{LaTeXdemo}
+%  \si{\kilogram\tothefourth}\\
+%  \si{\quartic\metre}
+%\end{LaTeXdemo}
+%
+%\DescribeMacro{\DeclareSIQualifier}
+% Following the syntax of the other macros, qualifiers are created
+% with the syntax \cs{DeclareSIQualifier}\marg{qualifier}\marg{symbol}.
+% In contrast to the other parts of a unit, there are no pre-defined
+% qualifiers. It is therefore entirely up to the user to create these.
+% For example, to identify the mass of a product created when using
+% a particular catalyst, the preamble could contain:
+%\begin{LaTeXdemo}[code only]
+%  \DeclareSIQualifier\polymer{pol}
+%  \DeclareSIQualifier\catalyst{cat}
+%\end{LaTeXdemo}
+% and then in the body the document could read:
+%\begin{LaTeXdemo}
+%  \SI{1.234}{\gram\polymer\per\mole\catalyst\per\hour}
+%\end{LaTeXdemo}
+%
+%\subsection{Tabular material}
+%
+% Aligning numbers in tabular content is handled by a new column
+% type, the \texttt{S} column. This new column type can align material
+% using a number of different strategies, with the aim of flexibility 
+% of output without needing to alter the input. The method used
+% as standard is to place the decimal marker in the number at the
+% centre of the cell and to align the material appropriately
+% (\cref{tab:S:standard}).
+%
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
-%    \caption{Behaviour of \texttt{S} column type}
-%    \label{tab:default}
+%    \caption{Standard behaviour of the \texttt{S} column type.}
+%    \label{tab:S:standard}
 %    \centering
-%    \begin{tabular}{%
-%      S%
-%      S[tabnumalign=centre,tabformat=2.4]%
-%      S[tabnumalign=right,tabformat=2.4]%
-%      S[tabnumalign=centre,tabformat=2.4,decimalsymbol=comma]}
+%    \begin{tabular}{S}
 %    \toprule
-%    {Some Values} & {Some Values} & {Some Values} & {Some Values} \\
+%      {Some Values} \\
 %    \midrule
-%     2.3456  &  2.3456  &  2.3456 &  2.3456 \\
-%    34.2345  & 34.2345  & 34.2345 & 34.2345 \\
-%    56.7835  & 56.7835  & 56.7835 & 56.7835 \\
-%    90.473   & 90.473   & 90.473  & 90.473  \\
+%         2.3456 \\
+%        34.2345 \\
+%        -6.7835 \\
+%        90.473  \\
+%      5642.5    \\
+%          1.2e3 \\
+%            e4  \\
 %    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-% The \opt{tabformat} setting can also be used to reserve space for
-% numbers containing exponents.  This is given in the same format as
-% above, but with a mantissa and exponent part (\ref{tab:exptab}).
-% Notice that this is designed to expect that numbers will contain a
-% mantissa.  Exponents can either be aligned so that the ``$\times$''
-% symbols match up vertically, or the exponent part can be allowed to
-% move across as needed. Space for signs is added by using any sign
-% in the \opt{tabformat}, so for example \opt{tabformat=+2.2} and
-% \opt{tabformat=-2.2} have exactly the same effect. Setting
-% \opt{tabformat} will automatically switch \opt{tabnumalign} from
-% \opt{centredecimal} to \opt{centre}, if the former is
-% currently set. In other cases, the current alignment option is
-% retained.
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+% 
+% The \texttt{S} column will attempt to automatically detect 
+% material which should be placed before or after a number, and will
+% maintain the alignment of the numerical data 
+% (\cref{tab:S:extras}). If the material could be mistaken for
+% part of a number, it should be protected by braces. The use of
+% \cs{color} in a table cell will also be detected an will override any
+% general colour applied by \pkg{siunitx}.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
-%    \caption{Exponents in tables}
-%    \label{tab:exptab}
+%    \caption{Detection of surrounding material in an \texttt{S} 
+%      column.}
+%    \label{tab:S:extras}
 %    \centering
-%    \begin{tabular}{%
-%      S[tabnumalign=right,tabformat=2.2e2]%
-%      S[tabnumalign=centre,tabformat=2.2e1.1]%
-%      S[tabnumalign=centre,tabformat=2.2e1.1,tabalignexp=false]%
-%      S[tabnumalign=centre,tabformat=+2.2]}
+%    \begin{tabular}{S[color=orange]}
 %    \toprule
-%        {Longer values}
-%      & {Longer values}
-%      & {Longer values}
-%      & {Values} \\
+%      {Some Values} \\
 %    \midrule
-%    2.3e1    &  2.34e1  &  2.34e1  & +2.31 \\
-%    34.23e45 & 34.23e45 & 34.23e45 & 34.23 \\
-%    56.78    & 56.78    & 56.78    & -56.78 \\
-%    1.0e34   & 1.0e34   & 1.0e34   & +-1.0 \\
+%      12.34 \\
+%      \color{purple} 975,31 \\
+%      44.268 \textsuperscript{\emph{a}} \\
 %    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-% Data not to be processed as a number should be protected by
-% wrapping it in braces: this is most likely to be true for column
-% headers (again as illustrated).  By default, the contents of
-% non-numeric cells are centred.  This can be altered by setting
-% \opt{tabtextalign}, which can be set to \opt{left}, \opt{right} or
-% \opt{centre}.  The use of digit separators in table columns is
-% accounted for: extra space is reserved if digit separators will be
-% added.
-%
-%\subsection{Columns of units}
-% As a complement to the |S| column, \currpkg also provides a second
-% column type, |s|.  This is intended for producing columns of units.
-% The letters chosen are intended to be similar to \cs{SI} and
-% \cs{si}, respectively.  The alignment of material in |s| columns is
-% governed by the \opt{tabunitalign} option.
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+%
+% As a complement to the \texttt{S} column, \pkg{siunitx} also provides
+% a second column type, \texttt{s}.  This is intended for producing 
+% columns of units. The letters chosen are intended to be similar to 
+% \cs{SI} and \cs{si}, respectively. This allows both macro-based and 
+% explicit units to be printed easily (\cref{tab:s:demo}).
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
-%  \centering
-%  \caption{Number and units in tables}
-%  \label{tab:num-unit}
-%    \begin{tabular}{%
-%      S[tabformat=1.2e-1,tabnumalign=centre]%
-%      s[tabunitalign=left]}
-%    \toprule
-%      {Value} & \multicolumn{1}{c}{Unit} \\
-%    \midrule
-%      2.16e-5 & \metre\squared\per\second \\
-%      2.83e-6 & \metre\squared\per\second \\
-%      7.39e3  & \pascal\cubic\metre\per\mole \\
-%      1.0e5   & \pascal \\
-%    \bottomrule
+%    \centering
+%    \caption{Units in tables.}
+%    \label{tab:s:demo}
+%    \begin{tabular}{s}
+%      \toprule
+%        \multicolumn{1}{c}{Unit} \\
+%      \midrule
+%        \metre\squared\per\second \\
+%        \pascal \\
+%        m.s^{-1} \\
+%      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
+%\end{LaTeXdemo}
 %
-% As the \cs{si} macro can take literal or macro input, the |s|
-% column cannot validate the input.  \emph{Everything} in an |s|
+% As the \cs{si} macro can take literal or macro input, the \texttt{s}
+% column cannot validate the input.  \emph{Everything} in an \texttt{s}
 % column is therefore passed to the \cs{si} macro for processing.  To
 % prevent this, you have to use \cs{multicolumn}, as is shown in
-% \ref{tab:s-limits}.  Notice that the braces do not prevent
+% \cref{tab:s:processing}.  Notice that the braces do not prevent
 % processing and colouring of the cell contents.
-%\begin{LaTeXexample}[float]
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
+%    \centering
+%    \caption{The \texttt{s} column processes everything.}
+%    \label{tab:s:processing}
+%    \sisetup{color = orange}
+%    \begin{tabular}{ss}      
+%      \toprule
+%        {Unit}     & \multicolumn{1}{c}{Unit}\\
+%      \midrule
+%        {\si{m^3}} & \multicolumn{1}{c}{\si{m^3}} \\
+%        \kilogram  & \kilogram \\
+%      \bottomrule
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
+%
+%\section{The key--value control system}
+%
+%\DescribeMacro{\sisetup}
+% The behaviour of the \pkg{siunitx} package is controlled by a 
+% number of key--value options. These can be given globally using
+% the \cs{sisetup} function or locally as the optional argument to the
+% user macros. 
+%  
+% The package uses a range of different key types:
+%\begin{description}
+%  \item[\texttt{Choice}] Takes a limited number of choices, which 
+%    are described separately for each key. 
+%  \item[\texttt{Integer}] Requires a number as the argument.
+%  \item[\texttt{Literal}] A key which uses the value(s) given directly,
+%    either to check input (for example the \texttt{input-digits} key)
+%    or in output.
+%  \item[\texttt{Math}] Similar to a \texttt{literal} option, but the
+%    input is always used in math mode, irrespective of other 
+%    \pkg{siunitx} settings. Thus to text-mode only input must be
+%    placed inside the argument of a \cs{text} macro.
+%  \item[\texttt{Macro}] Requires a macro, which may need a single 
+%    argument.
+%  \item[\texttt{Meta}] These are options which actually apply 
+%    a number of other options. As such, they do not take any
+%    value at all.
+%  \item[\texttt{Switch}] These are on--off switches, and recognise
+%    \opt{true} and \opt{false}.  Giving just the key name also 
+%    turns the key on.
+%\end{description}
+% The tables of option names use these descriptions to indicate how the
+% keys should be used.
+%
+%\subsection{Detecting fonts}
+%
+% The \pkg{siunitx} package controls the font used to print output
+% independently of the surrounding material.  The standard method is to
+% ignore the surroundings entirely, and to use the current body fonts.
+% However, the package can detect and follow surrounding bold, italic 
+% and font family changes. The font detection options are summarised in 
+% \cref{tab:opt:font:det}.
+%\begin{table}
 %  \centering
-%  \caption{The \texttt{s} column processes everything}
-%  \label{tab:s-limits}
-%    \begin{tabular}{%
-%      s[colourall,colour=orange]%
-%      s[colourall,colour=orange]}
+%  \caption{Font detection options.}
+%  \label{tab:opt:font:det}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      {Unit}    & \multicolumn{1}{c}{Unit}\\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
 %    \midrule
-%      {m^3}     & \multicolumn{1}{c}{\si{m^3}} \\
-%      \kilogram & \kilogram \\
+%      detect-all           & Meta   & \meta{none} \\
+%      detect-display-math  & Switch & false       \\
+%      detect-family        & Switch & false       \\
+%      detect-inline-weight & Choice & text        \\
+%      detect-italic        & Switch & false       \\
+%      detect-mode          & Switch & false       \\
+%      detect-none          & Meta   & \meta{none} \\ 
+%      detect-weight        & Switch & false       \\ 
 %    \bottomrule
-%    \end{tabular}
-%  \end{table}
-%\end{LaTeXexample}
+%  \end{tabular}
+%\end{table}
 %
-%\section{Angles}
-%\DescribeMacro{\ang}
-% Angles can be typeset using the \cs{ang} command.  This takes two
-% arguments, \cs{ang}\oarg{options}\marg{angle}, where \meta{options}
-% can be any of the package options to apply only to this value.
-% \meta{angle} can be given either as a decimal number or as a
-% semi-colon separated list of degrees, minutes and seconds, \ie\
-% \cs{ang}\marg{decimal angle} or
-% \cs{ang}|{|\meta{degrees}|;|\meta{minutes}|;|\meta{seconds}|}|. By
-% default, no space is introduced between angles and the degrees,
-% minutes and seconds markers.
-%\begin{LaTeXexample}
-%  \ang{10} \ang{12.3} \ang{4,5}\\
-%  \ang{1;2;3} \ang{;;1}\\
-%  \ang{+10;;} \ang{-0;1;}
-%\end{LaTeXexample}
-%
-% By default, angles with no degrees (or minutes) are zero-filled;
-% angles with degrees but no minutes or seconds are not filled.  This
-% behaviour can be altered using the package options.
-%\begin{LaTeXexample}
-%  \ang{;;1} \ang[padangle=none]{;;1}\\
-%  \ang{2;;} \ang[padangle=all]{2;;}\\
-%  \sisetup{padangle=all} \ang{;3;} \ang{4;;} \ang{;;5}
-%\end{LaTeXexample}
-% The \cs{num} macro is used to typeset each number of the angle, so
-% the options for \cs{num} also apply here.  The \opt{anglesep} value
-% can be used to separate degrees, minutes and seconds.
-%\begin{LaTeXexample}
-%  \ang{1.05}    \ang[decimalsymbol=comma]{1.05}\\
-%  \ang{3.67890} \ang[digitsep=comma]{3.67890}\\
-%  \ang{9;8;7}   \ang[anglesep=thin]{9;8;7}
-%\end{LaTeXexample}
-% The degrees, minutes and seconds signs can be placed over the
-% decimal sign using the \opt{astroang} option.  This is designed on
-% the assumption that only the last number given has a decimal
-% part.
-%\begin{LaTeXexample}
-%  \ang{1.2} \ang[astroang]{1.2}\\
-%  \ang{1;2.3;} \ang[astroang]{1;2.3;}\\
-%  \ang{1;2;3.4} \ang[astroang]{1;2;3.4}
-%\end{LaTeXexample}
-%
-%\section{Units and values}
-%\DescribeMacro{\SI}
-% The core aim of \currpkg is correctly typesetting values which have
-% units. The main output macro here is \cs{SI}, which has the same
-% syntax as the macros with the same name in \SIstyle and \unitsdef
-% packages. The \cs{SI} macro takes two mandatory arguments, in
-% addition to the optional set up argument, and a second optional
-% argument:
-% \cs{SI}\oarg{options}\marg{number}\oarg{preunit}\marg{unit}.  The
-% \meta{number} argument operates in exactly the same manner as the
-% equivalent argument of the \cs{num} macro.  \meta{unit} will be
-% typeset with a non-breakable space between it and the preceding
-% number, with font control as outlined earlier.  Finally,
-% \meta{preunit} is a unit to be typeset \emph{before} the numerical
-% value (most likely to be a currency).  Some examples illustrate the
-% general power of the macro.
-%\begin{LaTeXexample}
-%  \SI[mode=text]{1.23}{J.mol^{-1}.K^{-1}}\\
-%  \SI{.23e7}{\candela}\\
-%  \SI[per=slash]{1.99}[\pounds]{\per\kilogram}\\
-%  \SI{70}{\metre\per\second}\\
-%  \SI[per=frac,fraction=nice]{1,345}{\ampere\per\mole}
-%\end{LaTeXexample}
-% The use of unit macros outside of the \cs{SI} macro is described
-% later.
-%
-%\subsection{Literal units}
-%\changes{v1.1}{2008/07/23}{Unit processor extended to interpret
-%  \texttt{\textunderscore} correctly}
-% Units can be input in two ways, inspired by \SIstyle and \SIunits.
-% The \SIstyle-like method uses literal input.  Five characters have
-% a special meaning:
-%\begin{itemize}
-%  \item ``|^|'' and ``|_|''  The superscript and subscript
-%    characters can be used without the usual
-%    need for surrounding maths characters (|$|);^^A$
-%  \item ``|.|'' and ``|,|'': the full stop (point) symbol and comma
-%    are made active, and produce the current contents of the
-%    \opt{unitsep} option;
-%  \item ``|~|'' The contents of the \opt{unitspace} option are typeset
-%    by a tilde.
-%\end{itemize}
-% This allows ready input of units.
-%\begin{LaTeXexample}
-%  \SI{10}{kg.m.s^{-2}}\\
-%  \SI{1.453}{g/cm^3}\\
-%  \SI{6.345}{kg_{pol}.mmol_{cat}^{-1}}\\
-%  \SI{33.562}{cd~s}\\
-%  \SI[unitsep=medium]{100}{m.s^{-2}}
-%\end{LaTeXexample}
-% The literal unit system will correctly typeset input containing the
-% symbols \si{\micro} (micro), \si{\degree} (degree) and
-% \si{\angstrom} (ring-A).\footnote{Currently this works with \XeTeX\
-% and \pkg{inputenc} using the \texttt{latin1}, \texttt{latin5} and
-% \texttt{latin9} encodings.}
-% \begingroup\makeatletter\si@unt@nonlatin
-%\begin{LaTeXexample}
-%  \SI{10}{µm}\\
-%  \SI{20}{°C}\\
-%  \SI{30}{Å}
-%\end{LaTeXexample}
-%\endgroup
-%
-%\DescribeOption{allowlitunits}
-%\changes{v1.2f}{2009/02/20}{New \opt{allowlitunits} option}
-% Some users may prefer to completely disable the use of literal
-% input in units, for example to enforce consistency. This can be
-% accomplished by setting the \opt{allowlitunits} option to 
-% \opt{false}: the standard setting is \defaultopt{true}.
-%
-%\subsection{The unit interpreter}
-% The second operation mode for the \cs{SI} macro is based on the
-% behaviour of \SIunits.  Here, each unit, SI multiple prefix and
-% power is given a macro name.  These are entered in a method very
-% similar to the reading of the unit name in English.
-%\begin{LaTeXexample}
-%  \SI{10}{\kilo\gram\metre\per\second\squared}\\
-%  \SI{1.453}{\gram\per\cubic\centi\metre}\\
-%  \SI{33.562}{\candela\second}\\
-%  \SI[unitsep=medium]{100}{\metre\per\Square\second}\\
-%  \SI[prefixsymbolic=false]{4.56}{\kilo\metre\per\second}
-%\end{LaTeXexample}
-% On its own, this is very similar to \SIunits, and is less
-% convenient than the direct input method.\footnote{Users of \SIunits
-% should note the lack of need for a \cs{usk}-type macro.}  However,
-% the package allows you to define new unit macros; a large number of
-% pre-defined abbreviations are also supplied.  More importantly, by
-% defining macros for units, instead of literal values, new
-% functionality is made available.  Units may be re-defined to give
-% different output, and handling of reciprocal values can be altered.
-%\begin{LaTeXexample}
-%  \SI[per=frac,fraction=frac]{10}{\gram\metre\per\second\squared}\\
-%  \SI[per=slash]{1.453}{\gram\per\cubic\centi\metre}\\
-%  \SI{33.562}{\candela\second}\\
-%  \SI[per=frac,fraction=nice]{100}{\metre\per\Square\second}
-%\end{LaTeXexample}
-% The unit processor will trap \emph{some} errors in the input and
-% give the ``best guess'' result.  However, it is down to the user to
-% check the output.
-%
-%\subsection{Powers of units}
-%\DescribeMacro{\Square}
-%\DescribeMacro{\ssquare}
-%\DescribeMacro{\squared}
-%\DescribeMacro{\cubic}
-%\DescribeMacro{\cubed}
-% Including powers in units is handled using a ``natural language''
-% method.  Thus preceding a unit by \cs{Square} or \cs{cubic} which
-% raise the unit to the appropriate power, while \cs{squared} or
-% \cs{cubed} follow the unit they apply to. The \cs{Square} macro is
-% capitalised to avoid a name clash with \pkg{pstricks}; the
-% alternative \cs{ssquare} is also provided.
-%\begin{LaTeXexample}
-%  \SI{10}{\metre\squared}\\
-%  \SI{20}{\Square\metre}\\
-%  \SI{30}{\metre\cubed}\\
-%  \SI{40}{\cubic\metre}
-%\end{LaTeXexample}
+%\DescribeOption{detect-weight}
+%\DescribeOption{detect-family}
+%\DescribeOption{detect-italic}
+%\DescribeOption{detect-mode}
+% The options \opt{detect-weight} and \opt{detect-italic} set detection
+% of the prevailing font weight and italic states, respectively. The 
+% italic state is only checked if the surrounding material is not in 
+% math mode (as math text is always italic). Detecting the current 
+% family (roman, sans serif or monospaced) is controlled by the 
+% \opt{detect-family} setting, while the current mode (text or math) 
+% is detected using the \opt{detect-mode} switch. 
+%\DescribeOption{detect-all}
+%\DescribeOption{detect-none}
+% For convenience, all of the preceding options can be turned on or
+% off in one go using the \opt{detect-all} and \opt{detect-none}
+% options.  As the names indicate, \opt{detect-all} sets all
+% of \opt{detect-weight}, \opt{detect-family}, \opt{detect-italic}
+% and \opt{detect-mode} to \texttt{true}, while \opt{detect-none}
+% sets all of them to \texttt{false}.
+% 
+%\DescribeOption{detect-inline-weight}
+% Font weight detection is influenced by the value of 
+% \opt{detect-inline-weight}, which takes values \opt{text}, \opt{math} 
+% and \opt{combined}.  The package can detect the local value of font 
+% weight for either the surrounding text, or the surrounding inline 
+% ("$" \ldots "$") math. The \opt{combined} option checks both and uses 
+% the prevailing weight if either test is true.
+%\begin{LaTeXdemo}
+%  \sisetup{
+%    detect-weight        = true, 
+%    detect-inline-weight = math
+%  }%
+%  $\num{1234}$ \\
+%  { \boldmath $\num{1234}$ } \\ 
+%  { \bfseries $\num{1234}$ } \\
+%   \sisetup{detect-inline-weight = text}
+%  { \boldmath $\num{1234}$ } \\
+%  { \bfseries $\num{1234}$ }
+%\end{LaTeXdemo} 
+%
+%\DescribeOption{detect-display-math}
+% The font detection system can treat displayed mathematical content
+% in two ways.  This is controlled by the \opt{detect-display-math}
+% option. When set \opt{true}, display mathematics is treated 
+% independently from the body of the document.  Thus the local 
+% \emph{math} font is checked for matching.  In contrast, when set 
+% \opt{false}, display material is treated with the current running 
+% text font.
+%\begin{LaTeXdemo}
+%  \sffamily
+%  Some text
+%  \sisetup{
+%    detect-family,
+%    detect-display-math = true
+%  }
+%  \[ x = \SI{1.2e3}{\kilogram\kelvin\candela} \]
+%  More text
+%  \sisetup{detect-display-math = false}
+%  \[ y = \SI{3}{\metre\second\mole} \]
+%\end{LaTeXdemo}
 %
-%\DescribeMacro{\per}
-% The \cs{per} macro intelligently creates reciprocal powers, and
-% also adds the power $-1$ when appropriate.
-%\begin{LaTeXexample}
-%  \SI{10}{\per\second\squared}\\
-%  \SI{20}{\per\Square\second}\\
-%  \SI[per=frac,fraction=nice]{30}{\per\second\cubed}\\
-%  \SI[per=slash]{40}{\per\cubic\second}\\
-%  \SI{50}{\per\second}\\
-%  \SI{60}{\per\metre\Square\candela}
-%\end{LaTeXexample}
+%\subsection{Output font families}
 %
-%\DescribeMacro{\tothe}
-%\DescribeMacro{\raiseto}
-% For powers not defined above or with \cs{newpower}, the \cs{tothe}
-% macro can be used ``in line'' to produce a power.  As follows from
-% standard English usage, this comes after the unit. \cs{raiseto}
-% achieves the same, but is used \emph{before} a unit to add a power
-% \emph{after}.\footnote{\cs{raiseto} acts in the same way as
-% \cs{tothe} when used in a literal context: the power will be
-% produced where the macro is, rather than moving after the next
-% item.}
-%\begin{LaTeXexample}
-%  \SI{16.86}{\metre\tothe{4}}\\
-%  \SI{7.895}{\raiseto{-6}\newton}\\
-%  \SI{1.34}{\per\kelvin\tothe{7}}
-%\end{LaTeXexample}
-%
-%\subsection{Units with no values}
-%\DescribeMacro{\si}
-% For typesetting the symbol for a unit on its own, with the full
-% font control and without extra spaces, the \cs{si} macro is
-% provided.\footnote{The same effect can be achieved using the
-% \cs{SI} macro with an empty numerical argument.}  The macro name
-% avoids a clash with the functionality of the earlier packages, but
-% is similar to \cs{ilu} from the \unitsdef package.
-%\begin{LaTeXexample}
-%  \SI{}{kg.m/s^2}\\
-%  \si{kg.m/s^2}\\
-%  \si[mode=text,unitsep=thin]{\mole\per\cubic\deci\metre}
-%\end{LaTeXexample}
-%
-%\subsection{Free-standing units}
-% Users of the \unitsdef package will be accustomed to using unit
-% macros on their own (following a value) or with an optional
-% argument containing a number.  In both cases, only a single unit
-% macro could be used. \currpkg supports both operation modes, with
-% the limitation that units trailing values loose font control of the
-% value.  When used in this way, the units \emph{do not} take an
-% optional \pkg{keyval} argument.
-%\begin{LaTeXexample}
-%  \sisetup{prespace,allowoptarg}
-%  123\metre\\
-%  \kelvin[123]\\
-%  \sisetup{mode=text} \ampere[234]\\
-%  6\second
-%\end{LaTeXexample}
-%
-%\subsection{Pre-defined units, prefixes and powers}
-%\newcommand*{\csindex}[1]{^^A
-%  \cs{#1}^^A
-%  \expandafter\SpecialUsageIndex\csname#1\endcsname}
-%\newcommand*{\unitinfo}[1]{^^A
-%  #1 & \csindex{#1} &
-%  \expandafter\si\expandafter{\csname#1\endcsname}}
+% The relationship between font family detected and font family used
+% for output is not fixed. The font detected by the package in the 
+% surrounding material does not have to match that used for output.
+% 
 %\begin{table}
-%  \caption{The seven base SI units}
-%  \label{tab:baseunits}
 %  \centering
-%  \begin{tabular}{lll}
+%  \caption{^^A
+%    Font options (also available as \opt{number-\ldots} and 
+%    \opt{unit-\ldots} versions).
+%  }
+%  \label{tab:opt:font:set}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
 %    \midrule
-%    \unitinfo{kilogram}\\
-%    \unitinfo{metre}\\
-%    \unitinfo{second}\\
-%    \unitinfo{mole}\\
-%    \unitinfo{kelvin}\\
-%    \unitinfo{ampere}\\
-%    \unitinfo{candela}\\
+%      color   & Literal & \meta{none}   \\
+%      math-rm & Macro   & \cs{mathrm}   \\
+%      math-sf & Macro   & \cs{mathsf}   \\ 
+%      math-tt & Macro   & \cs{mathtt}   \\
+%      mode    & Choice  & math          \\
+%      text-rm & Macro   & \cs{rmfamily} \\
+%      text-sf & Macro   & \cs{sffamily} \\ 
+%      text-tt & Macro   & \cs{ttfamily} \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
-%\DescribeMacro{\metre}
-%\DescribeMacro{\meter}
-% The package always defines the seven base SI units, irrespective of
-% any package options given (\ref{tab:baseunits}). The kilogram is
-% notable as by default it is a \emph{base} unit with a prefix. Thus,
-% when the package is loaded with the option \opt{load=\{\}},
-% \cs{kilo} and \cs{gram} \emph{are not defined}.  As metre is often
-% spelled as ``meter'' in the US, the macro \cs{meter} is provided in
-% addition to the \cs{metre} macro.\footnote{The official SI spelling
-% for the unit is ``metre''.}
-%
-% By default, a number of additional definitions are created by the
-% package.  These are controlled by the \opt{load} and \opt{noload}
-% options. Unless specifically requested with the option
-% \opt{noload=prefix}, \currpkg defines the standard prefixes for
-% powers of ten (\ref{tab:prefix}).  This leads to the redefinition
-% of \cs{kilogram} as \cs{kilo}\cs{gram}.  The macro \cs{deka} is
-% provided, as this is used as an alias for \cs{deca} in some places.
-% The package also defines a number of derived SI units which have
-% assigned names and symbols (\ref{tab:derived}). Note that \cs{Gray}
-% is capitalised to avoid a name clash with the \pkg{pstricks}
-% package.\footnote{The macros \cs{ohm} and \cs{celsius} are not
-% defined by \currpkg if the \pkg{gensymb} package is loaded.}
-%\newcommand*{\prefixunitsym}[1]{\si[prefixsymbolic=false]{#1}}
-%\newcommand*{\prefixinfo}[1]{^^A
-%  #1 & \csindex{#1} &
-%    \expandafter\prefixunitsym\expandafter{\csname#1\endcsname} &
-%    \expandafter\si\expandafter{\csname#1\endcsname}}
+%
+%\DescribeOption{mode}
+% The \opt{mode} option determines whether \pkg{siunitx} uses
+% math or text mode when printing output. The choices are \opt{math} and
+% \opt{text}. When using math mode, text is printed using a math font 
+% whereas in text mode a text font is used.  The extent to which this is 
+% visually obvious depends on the fonts in use in the document. This 
+% manual uses old style (lower-case) figures in text mode to highlight 
+% the differences. This option has no effect if the \opt{detect-mode} 
+% switch is \opt{true}.
+% 
+%\DescribeOption{math-rm}
+%\DescribeOption{math-sf}
+%\DescribeOption{math-tt}
+%\DescribeOption{text-rm}
+%\DescribeOption{text-sf}
+%\DescribeOption{text-tt}
+% If font family detection is inactive, \pkg{siunitx} uses the font
+% family stored in either \opt{math-rm} or \opt{text-rm} for
+% output. The choice of \opt{math} or \opt{text} depends on the
+% \opt{mode} setting. If font family detection is active, 
+% \pkg{siunitx} may be using a sans serif or monospaced font for 
+% output. In math mode, these are stored in \opt{math-sf} and 
+% \opt{math-tt}, and for text mode in \opt{text-sf} and \opt{text-tt}. 
+% Notice that the detected and output font families can differ.
+%\begin{LaTeXdemo}
+%  \sisetup{detect-family}%
+%  \num{1234} \\
+%  { \sffamily \num{1234} } \\
+%  \SI{99}{\metre} \\
+%  \sisetup{math-rm = \mathtt}%
+%  \SI{99}{\metre} 
+%\end{LaTeXdemo}
+% 
+%\DescribeOption{color} 
+% The colour of printed output can be set using the \opt{color} 
+% option. When no colour is given, printing follows the surrounding 
+% text. In contrast, when a specific colour is given, it is used 
+% irrespective of the surroundings. As there are a number of different
+% colour models available, it is left to to user to load \pkg{color} or
+% a more powerful colour package.
+%\begin{LaTeXdemo}
+%  \color{red}
+%  Some text \\
+%  \SI{4}{\metre\per\sievert} \\
+%  More text \\
+%  \SI[color = blue]{4}{\metre\per\sievert} \\
+%  Still red here!
+%\end{LaTeXdemo}
+%
+% Every one of the font options can be given independently for units 
+% and number, with the prefixes \opt{unit-} and \opt{number-}, 
+% respectively. This allows fine control of output.
+%\begin{LaTeXdemo}
+%  \SI{4}{\angstrom} \\
+%  \SI[number-color = green]{4}{\angstrom} \\
+%  \SI[unit-color = green]{4}{\angstrom}
+%\end{LaTeXdemo}
+% 
+%\subsection{Parsing numbers}
+% 
+% The package uses a sophisticated parsing system to understand 
+% numbers. This allows \pkg{siunitx} to carry out a range of
+% formatting, as described later. All of the input options take lists of
+% literal tokens, and are summarised in \cref{tab:opt:num:in}.
+% 
 %\begin{table}
-%  \caption{The SI prefixes (\opt{load=prefix})}
-%  \label{tab:prefix}
 %  \centering
-%  \begin{tabular}{lllclllc}
+%  \caption{Options for number parsing.}
+%  \label{tab:opt:num:in}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Prefix} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Power} &
-%      Symbol &
-%      \multicolumn{1}{c}{Prefix} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Power} &
-%      Symbol \\
-%    \midrule
-%    \prefixinfo{yocto} &
-%    \prefixinfo{deca} \\
-%    \prefixinfo{zepto} &
-%    \prefixinfo{hecto} \\
-%    \prefixinfo{atto} &
-%    \prefixinfo{kilo} \\
-%    \prefixinfo{femto} &
-%    \prefixinfo{mega} \\
-%    \prefixinfo{pico} &
-%    \prefixinfo{giga} \\
-%    \prefixinfo{nano} &
-%    \prefixinfo{tera} \\
-%    \prefixinfo{micro} &
-%    \prefixinfo{peta} \\
-%    \prefixinfo{milli} &
-%    \prefixinfo{exa} \\
-%    \prefixinfo{centi} &
-%    \prefixinfo{zetta} \\
-%    \prefixinfo{deci} &
-%    \prefixinfo{yotta} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      input-close-uncertainty & Literal & )                \\ 
+%      input-complex-roots     & Literal & ij               \\ 
+%      input-decimal-markers   & Literal & .,               \\
+%      input-digits            & Literal & 0123456789       \\
+%      input-exponent-markers  & Literal & dDeE             \\
+%      input-ignore            & Literal & \meta{none}      \\
+%      input-open-uncertainty  & Literal & (                \\ ^^A ) 
+%      input-protect-tokens    & Literal & \verb=\mp\pi\pm= \\
+%      input-signs             & Literal & +-\cs{pm}\cs{mp} \\
+%      input-symbols           & Literal & \cs{pi}          \\
+%      parse-numbers           & Switch  & true             \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
+%
+%\DescribeOption{input-digits}
+%\DescribeOption{input-decimal-markers}
+%\DescribeOption{input-signs}
+%\DescribeOption{input-exponent-markers} 
+% The basic parts of a number are the digits, any sign and a separator
+% between the integer and decimal parts. These are stored in the input
+% options \opt{input-digits}, \opt{input-decimal-markers} and 
+% \opt{input-signs}, respectively. More than one input decimal marker 
+% can be used: it will be converted by the package to the appropriate 
+% output marker. Numbers which include an exponent part also require 
+% a marker for the exponent: this again is taken from the range of 
+% tokens in the \opt{exponent markers} option.
+% 
+%\DescribeOption{input-symbols}
+%\DescribeOption{input-ignore}
+% As well as \enquote{normal} digits, the package will interpret 
+% symbolic \enquote{numbers} (such as \cs{pi}) correctly if they are 
+% included in the \opt{input-symbols} list. Tokens given in the 
+% \opt{input-ignore} list are totally passed over by \pkg{siunitx}: 
+% they will be removed from the input with no further processing.
+% 
+%\DescribeOption{input-open-uncertainty}
+%\DescribeOption{input-close-uncertainty} 
+% In some fields, it is common to give the uncertainty in a value 
+% in brackets after the main part of the number, for example 
+% \enquote{\num{1.234(5)}}. The opening and closing symbols used for 
+% this type of input are set as \opt{input-open-uncertainty} and 
+% \opt{input-close-uncertainty}.
+%
+%\DescribeOption{input-complex-roots}
+% When using complex numbers in input, the complex root 
+% (\( \mathrm{i} = \sqrt{-1}\)) is indicated by one of the tokens stored
+% in \opt{input-complex-roots}. The parser understands complex root 
+% symbols given either before or after the associated number (but will
+% detect any invalid arrangement):
+%\begin{LaTeXdemo}
+%  \num{9.99 + 88.8i} \\
+%  \num{9.99 + i88.8}
+%\end{LaTeXdemo} 
+% 
+%\DescribeOption{input-protect-tokens}
+% Some symbols can be problematic under expansion in LaTeX2e. To allow 
+% these to be used in input without issue, the package can protect these
+% tokens while expanding input. Symbols to be protected in this way 
+% should be listed in \opt{input-protect-tokens}.
+% 
+%\DescribeOption{parse-numbers}
+% The \opt{parse-numbers} option turns the entire parsing system on
+% and off. The option is made available for two reasons. First, if
+% all of the numbers in a document are to be reproduced \enquote{as 
+% given}, turning off the parser will represent a significant saving in
+% processing required. Second, it allows the use of arbitrary TeX
+% code in numbers. If the parser is turned off, the input will be
+% printed in math mode (requiring \cs{text} to protect any text
+% in the number).
+%\begin{LaTeXdemo}
+%  \num[parse-numbers = false]{\sqrt{2}}        \\
+%  \SI[parse-numbers = false]{\sqrt{3}}{\metre}
+%\end{LaTeXdemo}
+%
+%\subsection{Post-processing numbers}
+%
+% Before typesetting numbers, various post-processing steps can be 
+% carried out. These involve adding or removing information from the 
+% number in a systematic way; the options are summarised in 
+% \cref{tab:opt:num:post}.
+%
 %\begin{table}
-%  \changes{v1.2n}{2009/09/16}{New \cs{degreeCelsius} unit}
-%  \caption{The derived SI units with defined names
-%    (\opt{load=named})}
-%  \label{tab:derived}
 %  \centering
-%  \begin{tabular}{llllll}
+%  \caption{Number post-processing options.}
+%  \label{tab:opt:num:post}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} &
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
 %    \midrule
-%    \unitinfo{becquerel} &
-%    \unitinfo{lux} \\
-%    \unitinfo{celsius} &
-%    \unitinfo{newton} \\
-%      & \csindex{degreeCelsius} & \degreeCelsius & 
-%    \unitinfo{ohm}  \\
-%    \unitinfo{coulomb} &
-%    \unitinfo{pascal} \\
-%    \unitinfo{farad} &
-%    \unitinfo{radian} \\
-%    \unitinfo{Gray} &
-%    \unitinfo{siemens} \\
-%      & \csindex{ggray} & \ggray &
-%    \unitinfo{sievert} \\
-%    \unitinfo{hertz} &
-%    \unitinfo{steradian} \\
-%    \unitinfo{henry} &
-%    \unitinfo{tesla} \\
-%    \unitinfo{joule} &
-%    \unitinfo{volt} \\
-%    \unitinfo{katal} &
-%    \unitinfo{watt} \\
-%    \unitinfo{lumen} &
-%    \unitinfo{weber} \\
+%      add-decimal-zero      & Switch  & true     \\
+%      add-integer-zero      & Switch  & true     \\
+%      explicit-sign         & Literal & \m{none} \\
+%      retain-explicit-plus  & Switch  & false    \\
+%      retain-unity-mantissa & Switch  & true     \\
+%      retain-zero-exponent  & Switch  & false    \\
+%      round-mode            & Choice  & off      \\
+%      round-precision       & Integer & 2        \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
 %
-% In addition to these units, there are three other groups of units
-% for use with the SI system which do not fit into the above.  These
-% are those derived from physical measurements
-% (\ref{tab:experimental}), those considered ``accepted''
-% (\ref{tab:accepted}), and those accepted temporarily
-% (\ref{tab:addn}).\footnote{These are supposed to be replaced over
-% time by SI units.}
-%\DescribeMacro{\litre}
-%\DescribeMacro{\liter}
-% The unit ``litre'' is often spelled ``liter'' in the US; both
-% spellings are provided by \currpkg, with \cs{liter} giving
-% \si{\liter} and \cs{litre} producing \si{\litre}.
+%\DescribeOption{round-mode}
+%\DescribeOption{round-precision}
+% The \pkg{siunitx} package can round numerical input to a fixed
+% number of significant figures or decimal places. This is controlled by
+% the \opt{round-mode} option, which takes the choices \opt{off},
+% \opt{figures} and \opt{places}. When rounding is turned on, the
+% number of digits used (either decimal places or significant figures)
+% is set using the \opt{round-precision} option. No rounding will take
+% place if the number contains an uncertainty component.
+%\begin{LaTeXdemo}
+%  \num{1.23456} \\
+%  \num{14.23} \\
+%  \num{0.12345(9)} \\
+%  \sisetup{
+%    round-mode      = places,
+%    round-precision = 3
+%  }%
+%  \num{1.23456} \\
+%  \num{14.23} \\
+%  \num{0.12345(9)} \\
+%  \sisetup{
+%    round-mode      = figures,
+%    round-precision = 3
+%  }%
+%  \num{1.23456} \\
+%  \num{14.23} \\
+%  \num{0.12345(9)}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{add-decimal-zero}
+%\DescribeOption{add-integer-zero}
+% It is possible to give real (floating point) numbers as input omitting
+% the decimal or the integer parts of the number (for example \num{.123} 
+% or \num{123.}). The options \opt{add-decimal-zero} and 
+% \opt{add-integer-zero} allow the package to \enquote{fill in} the
+% missing zero.
+%\begin{LaTeXdemo}
+%  \num{123.} \\
+%  \num{456}  \\
+%  \num{.789} \\
+%  \sisetup{
+%    add-decimal-zero = false,
+%    add-integer-zero = false,
+%  }%
+%  \num{123.} \\
+%  \num{456}  \\
+%  \num{.789} 
+%\end{LaTeXdemo}
+%
+%\DescribeOption{explicit-sign}
+%\DescribeOption{retain-explicit-plus}
+% The inclusion of a leading plus sign is usually unnecessary for
+% positive numbers, and so the \opt{retain-explicit-plus} option is
+% available to control whether these are printed. At the same time, it
+% may be useful to force all numbers to have a sign. This behaviour
+% is controlled by the \opt{explicit-sign} option: this is used if
+% given and if no sign was present in the input.
+%\begin{LaTeXdemo}
+%  \num{+345} \\
+%  \num[retain-explicit-plus]{+345} \\
+%  \num[explicit-sign = -]{345}     \\
+%  \num[explicit-sign = -]{+345} 
+%\end{LaTeXdemo}
+%
+%\DescribeOption{retain-unity-mantissa}
+%\DescribeOption{retain-zero-exponent}
+% The retention of a zero exponent is controlled by the 
+% \opt{retain-zero-exponent} option. The retention of a mantissa of one
+% is likewise controlled by the \opt{retain-unity-mantissa} option.
+%\begin{LaTeXdemo}
+%  \num{1e4} \\
+%  \num[retain-unity-mantissa = false]{1e4} \\
+%  \num{444e0} \\
+%  \num[retain-zero-exponent = true]{444e0} 
+%\end{LaTeXdemo}
+%
+%\subsection{Printing numbers}
+%
+% Actually printing numbers is controlled by a number of settings,
+% which apply ideas such as differing decimal markers, digit
+% grouping and so on.  All of these options are concerned with the
+% appearance of output, rather than the data it conveys. The options are
+% summarised in \cref{tab:opt:num:out}.
+% 
 %\begin{table}
-%  \caption{Units derived from experiments
-%    (\opt{load=physical})}
-%  \label{tab:experimental}
 %  \centering
-%  \begin{tabular}{lll}
+%  \caption{Output options for numbers.}
+%  \label{tab:opt:num:out}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} \\
-%    \midrule
-%    electron volt & \csindex{electronvolt} & \electronvolt \\
-%    unified atomic mass unit
-%      & \csindex{atomicmassunit} & \atomicmassunit \\
-%      & \csindex{atomicmass} & \atomicmass \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule 
+%      brackets-numbers          & Switch  & true              \\ ^^A (
+%      close-bracket             & Literal & )                 \\ 
+%      complex-root-position     & Choice  & after-number      \\
+%      copy-decimal-marker       & Choice  & false             \\
+%      exponent-base             & Literal & 10                \\
+%      exponent-product          & Math    & \cs{times}        \\
+%      group-decimal-digits      & Switch  & true              \\
+%      group-digits              & Switch  & true              \\
+%      group-four-digits         & Switch  & false             \\
+%      group-integer-digits      & Switch  & true              \\
+%      group-separator           & Math    & \cs{,}            \\
+%      negative-color            & Literal & \meta{none}       \\
+%      open-bracket              & Literal & (                 
+%        \\ ^^A ) (
+%      output-close-uncertainty  & Literal & )                 \\ 
+%      output-complex-root       & Math    & \verb=\mathrm{i}= \\
+%      output-decimal-marker     & Math    & .                 \\
+%      output-open-uncertainty   & Literal & (                 \\ ^^A )
+%      range-phrase              & Literal & \verb*= to =      \\
+%      separate-uncertainty      & Switch  & false             \\
+%      tight-spacing             & Switch  & false             \\
+%      uncertainty-separator     & Math    & \meta{none}       \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
+%
+%\DescribeOption{group-digits}
+%\DescribeOption{group-decimal-digits}
+%\DescribeOption{group-integer-digits}
+%\DescribeOption{group-four-digits}
+%\DescribeOption{group-separator}
+% Grouping digits into blocks of three is a common method to increase
+% the ease of reading of numbers.  The \opt{group-digits} choice
+% turns this behaviour on and off, with grouping for numbers of exactly
+% four digits controlled by the \opt{group-four-digits} choice. Note
+% that the later only applies if \opt{group-digits} is turned on.
+% The separator used between groups of digits is stored by the 
+% \opt{group-separator} option.  This takes literal input and is
+% used in math mode: for a text-mode full space use "\text{~}".
+%\begin{LaTeXdemo}
+%  \num{12345} \\
+%  \num[group-digits = false]{12345} \\
+%  \num{1234} \\
+%  \num[group-four-digits = true]{1234} \\
+%  \num{12345} \\
+%  \num[group-separator = {,}]{12345} \\
+%  \num[group-separator = \text{~}]{12345} 
+%\end{LaTeXdemo} 
+% Grouping can be activated separately for the integer and decimal
+% parts of a number using the \opt{group-integer-digits} and 
+% \opt{group-decimal-digits} options.
+%\begin{LaTeXdemo}
+%  \sisetup{group-digits = false}%
+%  \num{12345.67890} \\
+%  \num[group-decimal-digits]{12345.67890} \\
+%  \num[group-integer-digits]{12345.67890} 
+%\end{LaTeXdemo}
+%
+%\DescribeOption{output-complex-root}
+%\DescribeOption{output-decimal-marker}
+%\DescribeOption{copy-decimal-marker}
+% The decimal marker used in output is set using the 
+% \opt{output-decimal-marker} option. This can differ from the input 
+% marker, as can the root of $\sqrt{-1}$, which is stored in the 
+% \opt{output-complex-root} option. The later is always in math mode, 
+% but the standard setting uses \cs{mathrm} to give an upright 
+% \enquote{i}: this can easily be altered. The decimal marker from
+% the input can be used in the output by setting the
+% \opt{copy-decimal-marker} option.
+%\begin{LaTeXdemo}
+%  \num{1.23} \\
+%  \num[output-decimal-marker = {,}]{1.23} \\
+%  \num{1+2i} \\
+%  \num[output-complex-root = \text{\ensuremath{i}}]{1+2i} \\
+%  \num[output-complex-root = j]{1+2i} \\
+%  \num[copy-decimal-marker]{555,555}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{complex-root-position}
+% The position of the complex root can be adjusted to place it
+% either before or after the associated numeral in a complex number
+% using the \opt{complex-root-position} option.
+%\begin{LaTeXdemo}
+%  \num{67-0.9i} \\
+%  \num[complex-root-position = before-number]{67-0.9i} \\
+%  \num[complex-root-position = after-number]{67-0.9i}
+%\end{LaTeXdemo}
+% 
+%\DescribeOption{exponent-base}
+%\DescribeOption{exponent-product}
+% When exponents are present in the input, the 
+% \opt{exponent-base} and \opt{exponent-product} options set the obvious
+% parts of the output.  Notice that the base is in the current mode, but
+% the product sign is always in math mode.
+%\begin{LaTeXdemo}
+%  \num[exponent-product = \times]{1e2} \\
+%  \num[exponent-product = \cdot]{1e2} \\
+%  \num[exponent-base = 2]{1e2}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{separate-uncertainty}
+%\DescribeOption{uncertainty-separator}
+%\DescribeOption{output-open-uncertainty}
+%\DescribeOption{output-close-uncertainty}
+% When input is given including an uncertainty in a value, it can be 
+% printed either with the uncertainty in brackets or as a separate 
+% number. This behaviour is controlled by the 
+% \opt{separate-uncertainty} choice. If the uncertainty is given in 
+% brackets, a space may be added between the main value and the 
+% uncertainty: this is stored using the \opt{uncertainty-separator}
+% option. The opening and closing brackets used are stored in 
+% \opt{output-open-uncertainty} and
+% \opt{output-close-uncertainty}, respectively.
+%\begin{LaTeXdemo}
+%  \num{1.234(5)} \\
+%  \num[separate-uncertainty = true]{1.234(5)} \\
+%  \sisetup{
+%    output-open-uncertainty  = [,
+%    output-close-uncertainty = ],
+%    uncertainty-separator    = {\,}
+%  }
+%  \num{1.234(5)}
+%\end{LaTeXdemo}
+% Notice that \pkg{siunitx} correctly interprets uncertainties which
+% cross the decimal marker position whether these are separated out
+% or not.
+%\begin{LaTeXdemo} 
+%  \num{8.2(13)} \\
+%  \num[separate-uncertainty]{8.2(13)}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{bracket-numbers}
+%\DescribeOption{open-bracket}
+%\DescribeOption{close-bracket}
+% There are certain combinations of numerical input which can be
+% ambiguous. This can be corrected by adding brackets in the appropriate
+% place, and is controlled by the \opt{bracket-numbers} switch.  The 
+% opening and closing brackets used are stored in \opt{open-bracket} and
+% \opt{close-bracket}, respectively. Note that \opt{bracket-numbers}
+% only applies to numbers without units: for numbers with units
+% see the \opt{multi-part-units} option.
+%\begin{LaTeXdemo}
+%  \num{1+2i e10} \\
+%  \num[bracket-numbers = false]{1+2i e10} \\
+%  \sisetup{
+%    open-bracket  = \{,
+%    close-bracket = \},
+%  }
+%  \num{1+2i e10}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{negative-color}
+% \pkg{siunitx} can detect negative mantissa values and alter print
+% colour accordingly. This is disabled by setting the option to an empty
+% value.
+%\begin{LaTeXdemo}
+%  \num{-15673} \\
+%  \num[negative-color = red]{-15673}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{tight-spacing}
+% Under some circumstances is may be desirable to \enquote{squeeze}
+% the output spacing.  This is turned on using the \opt{tight-spacing}
+% switch, which compresses spacing where possible.
+%\begin{LaTeXdemo}
+%  \num{1 \pm 2i e3} \\
+%  \num[tight-spacing = true]{1 \pm 2i e3} 
+%\end{LaTeXdemo}
+%
+% Lists and ranges of numbers have a small number of specialised
+% options, which apply on to these more unusual input forms 
+% (\cref{tab:opt:num:list}).
+%
 %\begin{table}
-%  \caption{Units accepted for use with SI
-%    (\opt{load=accepted})}
-%  \label{tab:accepted}
 %  \centering
-%  \begin{tabular}{lll}
+%  \caption{Output options for lists and ranges of numbers.}
+%  \label{tab:opt:num:list}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} \\
-%    \midrule
-%    \unitinfo{bel} \\
-%    day & \csindex{Day} & \Day \\
-%     & \csindex{dday} & \dday \\
-%    \unitinfo{degree} \\
-%    \unitinfo{hour} \\
-%    \unitinfo{litre} \\
-%     & \csindex{liter} & \liter \\
-%    \unitinfo{minute} \\
-%    minute (arc) & \csindex{arcmin} & \arcmin \\
-%    \unitinfo{neper} \\
-%    \unitinfo{percent} \\
-%    second (arc) & \csindex{arcsec} & \arcsec \\
-%    \unitinfo{tonne} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule 
+%      list-final-separator & Literal & \verb*= and =  \\
+%      list-separator       & Literal & \verb*=, =     \\
+%      range-phrase         & Literal & \verb*= to =   \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
+%
+%\DescribeOption{list-final-separator}
+%\DescribeOption{list-separator}
+% Lists of numbers are printed with a separator between each item,
+% which is stored using the \opt{list-separator} option. The
+% separator before the last item of a list may be different, and
+% is therefore set using the \opt{list-final-separator} option. Any
+% spaces needed should be included in the option settings: none are
+% added within the code.
+%\begin{LaTeXdemo}
+%  \numlist{0.1;0.2;0.3}                              \\
+%  \numlist[list-separator = {; }]{0.1;0.2;0.3}       \\
+%  \numlist[list-final-separator = {, }]{0.1;0.2;0.3} \\
+%  \numlist[
+%    list-separator       = { and },
+%    list-final-separator = { and finally }
+%  ]{0.1;0.2;0.3}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{range-phrase}
+% Ranges of numbers can be given as input. These will have an 
+% appropriate word or symbol inserted between the two entries: this
+% is stored using the \opt{range-phrase} option. The phrase should 
+% include any necessary spaces: no extra space is added.
+%\begin{LaTeXdemo}
+%  \numrange{5}{100} \\
+%  \numrange[range-phrase = --]{5}{100}
+%\end{LaTeXdemo}
+%
+%\subsection{Multi-part numbers}
+%
+% \pkg{siunitx} recognises the idea of products and quotients in 
+% numbers, both with and without units. These multi-part numbers have
+% a number of options affecting how they are processed. The options are
+% summarised in \cref{tab:opt:num:multi}.
+% 
 %\begin{table}
 %  \centering
-%  \caption{Additional (temporary) SI units
-%    (\opt{load=addn})}
-%  \label{tab:addn}
-%  \begin{tabular}{lll}
+%  \caption{Multi-part number options.}
+%  \label{tab:opt:num:multi}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%      \multicolumn{1}{c}{Unit} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Symbol} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      fraction-function  & Macro   & \cs{frac}  \\
+%      input-product      & Literal & x          \\
+%      input-quotient     & Literal & /          \\
+%      output-product     & Math    & \cs{times} \\
+%      output-quotient    & Math    & /          \\
+%      quotient-mode      & Choice  & symbol     \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+%\DescribeOption{input-product}
+%\DescribeOption{input-quotient}
+% The options \opt{input-product} and \opt{input-quotient} contain the
+% tokens used to determine if a number contains multiple parts.
+%\begin{LaTeXdemo}
+%  \num{1 x 2 x 3} \\
+%  \num{1e4 x 2(3) x 3/4} \\
+%  \num[input-product=*]{4 * 5 * 6} \\
+%  \num{ 1 / 2e4 } \\
+%  \num{ 1e2 / 3e4 }
+%\end{LaTeXdemo}
+%\DescribeOption{output-product}
+%\DescribeOption{output-quotient}
+% The symbols used for printing products and quotients are stored using
+% the options \opt{output-product} and \opt{output-quotient}.
+%\begin{LaTeXdemo}
+%  \num[output-product = \cdot]{4.87 x 5.321 x 6.90545} \\
+%  \num[output-quotient = \text{ div }]{1 / 2}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{quotient-mode}
+% For quotients, there is the possibility to print output either using
+% a slash, or using the \cs{frac} macro. This is controlled by the 
+% \opt{quotient} choice option, which takes values \opt{slash} and
+% \opt{fraction}.
+%\begin{LaTeXdemo}
+%  \num{1 / 2e4} \\
+%  \num[quotient-mode = fraction]{1 / 2e4}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{fraction-function}
+% The function used when \opt{quotient-mode = fraction} is set is 
+% determined by the \opt{fraction-function} option. This should
+% be set to a function which takes two arguments, and presumably
+% creates some type of fraction. Most alternatives to the standard
+% \cs{frac} function will involve loading additional packages: the
+% demonstrations here need \pkg{amsmath} and 
+% \pkg{xfrac}.\footnote{If \pkg{xfrac} is not available when typesetting
+% this document, the demonstration of \cs{sfrac} will have the wrong
+% appearance.}
+%\begin{LaTeXdemo}
+%  \sisetup{quotient-mode = fraction}
+%  \num{1 / 1}
+%  \num[fraction-function = \dfrac]{1 / 2} 
+%  \num[fraction-function = \sfrac]{1 / 3} 
+%  \num[fraction-function = \tfrac]{1 / 4} 
+%\end{LaTeXdemo}
+%
+%\subsection{Angles}
+%
+% Angle processing provided by the \cs{ang} function has a set of options 
+% which apply in addition to the general ones set up for number processing
+% (\cref{tab:opt:ang}).
+%
+%\begin{table}
+%  \centering
+%  \caption{Angle options.}
+%  \label{tab:opt:ang}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
+%    \toprule
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
 %    \midrule
-%    {\aa}ngstr{\"o}m & \csindex{angstrom} & \angstrom \\
-%    \unitinfo{are} \\
-%    \unitinfo{curie} \\
-%    bar & \csindex{BAR} & \BAR \\
-%     & \csindex{bbar} & \bbar \\
-%    \unitinfo{barn} \\
-%    \unitinfo{gal} \\
-%    \unitinfo{hectare} \\
-%    \unitinfo{millibar} \\
-%    \unitinfo{rad} \\
-%    \unitinfo{rem} \\
-%    \unitinfo{roentgen} \\
+%      add-arc-degree-zero       & Switch & false        \\
+%      add-arc-minute-zero       & Switch & false        \\ 
+%      add-arc-second-zero       & Switch & false        \\ 
+%      angle-symbol-over-decimal & Switch & false        \\
+%      arc-separator             & Math   & false        \\
+%      number-angle-separator    & Math   & \meta{empty} \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+%\DescribeOption{number-angle-separator}
+% The separator between the number and angle symbol (degrees, minutes
+% or seconds) can be set using the \opt{number-angle-separator}
+% option, independent of the related \opt{number-unit-separator}
+% option used by the \cs{SI} function.
+%\begin{LaTeXdemo}
+%  \ang{2.67} \\
+%  \ang[number-angle-separator = \,]{2.67}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{arc-separator}
+% When angles are printed in arc format, the separation of the different
+% parts is set up using the \opt{arc-separator} option.
+%\begin{LaTeXdemo}
+%  \ang{6;7;6.5} \\
+%  \ang[arc-separator = \,]{6;7;6.5}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{add-arc-degree-zero}
+%\DescribeOption{add-arc-minute-zero}
+%\DescribeOption{add-arc-second-zero}
+% Zero-filling for the degree, minute or second parts of an arc is
+% controlled using the \opt{add-arc-degree-zero}, 
+% \opt{add-arc-minute-zero} and \opt{add-arc-second-zero} options.
+% All are off as standard.
+%\begin{LaTeXdemo}
+%  \ang{-1;;} \\
+%  \ang{;-2;} \\
+%  \ang{;;-3} \\
+%  \sisetup{add-arc-degree-zero}
+%  \ang{-1;;} \\
+%  \ang{;-2;} \\
+%  \ang{;;-3} \\
+%  \sisetup{add-arc-minute-zero}
+%  \ang{-1;;} \\
+%  \ang{;-2;} \\
+%  \ang{;;-3} \\
+%  \sisetup{add-arc-second-zero}
+%  \ang{-1;;} \\
+%  \ang{;-2;} \\
+%  \ang{;;-3}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{angle-symbol-over-decimal}
+% In some subject areas, most notably astronomy, the angle symbols
+% are given over the decimal marker, rather than at the end of the
+% number. This behaviour is available using the 
+% \opt{angle-symbol-over-decimal} option.
+%\begin{LaTeXdemo}
+%  \ang{45.697}  \\
+%  \ang{6;7;6.5} \\
+%  \ang[angle-symbol-over-decimal]{45.697} \\
+%  \ang[angle-symbol-over-decimal]{6;7;6.5}
+%\end{LaTeXdemo}
+%
+%\subsection{Creating units}
+%\label{sec:units:creating}
+%
+% The various macro units are created at the start of the document. 
+% \pkg{siunitx} can define these such that they are only available for 
+% use within the \cs{si} and \cs{SI} functions, or can make the unit
+% macros available throughout the document body. There are a number of
+% settings which control this creation process 
+% (\cref{tab:opt:units:def}). As a result, these options all apply
+% in the preamble only.
+% 
+%\begin{table}
+%  \centering
+%  \caption{Unit creation options.}
+%  \label{tab:opt:units:def}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
+%    \toprule
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      free-standing-units    & Switch & false \\
+%      overwrite-functions    & Switch & false \\
+%      space-before-unit      & Switch & false \\
+%      unit-optional-argument & Switch & false \\
+%      use-xspace             & Switch & false \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
 %
-%\subsection{Prefixed and abbreviated units}
-% Many basic units have prefixes which are commonly used with the
-% unit, such as centimetre or megahertz.  The package therefore
-% defines a number of common prefixed units (\opt{load=prefixed}).
-% Several of these also have obvious abbreviations (such as \cs{MHz}
-% for \cs{megahertz}), which are made available by \opt{load=abbr}.
-% In common with the units discussed above, the prefixed and
-% abbreviated unit definitions are loaded by default.
-%\newcommand*{\tablesubhead}[1]{^^A
-%  \addlinespace \emph{#1} \\*}
-%\begin{longtable}{llll}
-%    \caption{Prefixed (\opt{load=prefixed}) and abbreviated
-%      (\opt{load=abbr}) units\label{tab:abbr}}\\
+%\DescribeOption{free-standing-units}
+%\DescribeOption{overwrite-functions}
+% The \opt{free-standing-units} option controls whether the unit macros 
+% exist outside of the \cs{si} and \cs{SI} arguments. When this option
+% is \opt{true}, \pkg{siunitx} creates the macros for general use.
+% The standard method to achieve this does not overwrite any existing
+% macros: this behaviour can be altered using the 
+% \opt{overwrite-functions} switch.
+% 
+%\DescribeOption{space-before-unit}
+%\DescribeOption{unit-optional-argument}
+%\DescribeOption{use-xspace}
+% When \enquote{free standing} unit macros are created, their behaviour
+% can be adjusted by a number of options. These are mainly intended for
+% emulating the input syntax of older packages. The option 
+% \opt{unit-optional-argument} gives the same behaviour for the
+% inputs
+%\begin{LaTeXdemo}[code only]
+%  \SI{10}{\metre}
+%\end{LaTeXdemo}
+% and
+%\begin{LaTeXdemo}[code only]
+%  \metre[10].
+%\end{LaTeXdemo}
+% The \opt{space-before-unit} and \opt{use-xspace} options control
+% the behaviour at the \enquote{ends} of the unit macros. Activating 
+% \opt{space-before-unit} inserts the number--unit space before the
+% unit is printed. This is suitable for the input syntax
+%\begin{LaTeXdemo}[code only]
+%  30\metre
+%\end{LaTeXdemo}
+% but does mean that the unit macros are incorrectly spaced in running
+% text.  On the other hand, the \opt{use-xspace} option attempts to
+% correctly space input such as
+%\begin{LaTeXdemo}[code only]
+%  \metre is the symbol for metres.
+%\end{LaTeXdemo}
+%
+%\subsection{Loading additional units}
+%
+%\DescribeOption{load-configurations}
+% \pkg{siunitx} includes a set of configuration files which are intended
+% to make life easier for the user. The files are loaded using the
+% \opt{load-configurations} option, which accepts a comma-separated of
+% file names.
+% 
+% The first configuration file provides a number of convenient 
+% abbreviations for the SI units (\cref{tab:unit:abbr}). The 
+% standard \pkg{siunitx} settings only create these abbreviations within
+% the scope of the \cs{si} and \cs{SI} functions, meaning that no 
+% clashes should occur (for example with the standard \cs{pm} symbol). 
+% 
+%\begin{center} 
+%  \tablecaption{Abbreviated units \endgraf
+%    (\opt{load-configurations=abbreviations}).}
+%  \label{tab:unit:abbr}
+%  \tablefirsthead{^^A
 %    \toprule
-%    Unit & Macro & Symbol & Abbreviation \\
+%      \multicolumn{1}{l}{Unit}   &
+%      \multicolumn{1}{l}{Abbreviation}  &
+%      \multicolumn{1}{l}{Symbol} \\
 %    \midrule
-%  \endfirsthead
+%  }
+%  \tablehead{^^A
+%    \multicolumn{3}{l}{\emph{Continued from previous page}} \\
 %    \toprule
-%    Unit & Macro & Symbol & Abbreviation \\
+%      \multicolumn{1}{l}{Unit}   &
+%      \multicolumn{1}{l}{Abbreviation}  &
+%      \multicolumn{1}{l}{Symbol} \\
 %    \midrule
-%  \endhead
-%    \bottomrule
-%    \multicolumn{4}{r}{\emph{Continued on next page}}
-%  \endfoot
+%  }
+%  \tabletail{^^A
 %    \bottomrule
-%  \endlastfoot
-%
-%  \tablesubhead{Masses}
-%  \unitinfo{kilogram} & \csindex{kg} \\
-%  \unitinfo{femtogram} & \csindex{fg} \\
-%  \unitinfo{picogram} & \csindex{pg} \\
-%  \unitinfo{nanogram} & \csindex{nanog} \\
-%  \unitinfo{microgram} & \csindex{micg} \\
-%  \unitinfo{milligram} & \csindex{mg} \\
-%  atomic mass & \csindex{atomicmass} & \amu & \csindex{amu} \\
-%
-%  \tablesubhead{Lengths}
-%  \unitinfo{picometre} & \csindex{picom} \\
-%  \unitinfo{nanometre} & \csindex{nm} \\
-%  \unitinfo{micrometre} & \csindex{micm} \\
-%  \unitinfo{millimetre} & \csindex{mm} \\
-%  \unitinfo{centimetre} & \csindex{cm} \\
-%  \unitinfo{decimetre} & \csindex{dm} \\
-%  \unitinfo{kilometre} & \csindex{km} \\
-%
-%  \tablesubhead{Times}
-%  \unitinfo{second} & \csindex{Sec} \\
-%  \unitinfo{attosecond} & \csindex{as} \\
-%  \unitinfo{femtosecond} & \csindex{fs} \\
-%  \unitinfo{picosecond} & \csindex{ps} \\
-%  \unitinfo{nanosecond} & \csindex{ns} \\
-%  \unitinfo{microsecond} & \csindex{mics} \\
-%  \unitinfo{millisecond} & \csindex{ms} \\
-%
-%  \tablesubhead{Moles}
-%  \unitinfo{femtomole} & \csindex{fmol} \\
-%  \unitinfo{picomole} & \csindex{pmol} \\
-%  \unitinfo{nanomole} & \csindex{nmol} \\
-%  \unitinfo{micromole} & \csindex{micmol} \\
-%  \unitinfo{millimole} & \csindex{mmol} \\
-%  \unitinfo{kilomole} & \csindex{kmol} \\
-%
-%  \tablesubhead{Currents}
-%  \unitinfo{picoampere} & \csindex{pA} \\
-%  \unitinfo{nanoampere} & \csindex{nA} \\
-%  \unitinfo{microampere} & \csindex{micA} \\
-%  \unitinfo{milliampere} & \csindex{mA} \\
-%  \unitinfo{kiloampere} & \csindex{kA} \\
-%
-%  \tablesubhead{Areas}
-%  square centimetre & \csindex{squarecentimetre} &
-%    \squarecentimetre & \csindex{cms} \\*
-%    & \csindex{centimetresquared} & \centimetresquared \\
-%  square metre & \csindex{squaremetre} & \squaremetre \\
-%  square kilometre & \csindex{squarekilometre} & \squarekilometre \\
-%
-%  \tablesubhead{Volumes}
-%\changes{v1.1d}{2008/10/29}{New units \cs{microliter}, \cs{milliliter},
-%  \cs{micL} and \cs{mL}}
-%  \unitinfo{microlitre} & \csindex{micl} \\
-%  \unitinfo{millilitre} & \csindex{ml} \\
-%  \unitinfo{microliter} & \csindex{micL} \\
-%  \unitinfo{milliliter} & \csindex{mL} \\
-%  cubic centimetre & \csindex{cubiccentimetre} &
-%    \cubiccentimetre & \csindex{cmc} \\*
-%    & \csindex{centimetrecubed} & \centimetrecubed \\
-%  cubic decimetre & \csindex{cubicdecimetre} &
-%    \cubicdecimetre & \csindex{dmc} \\
-%
-%  \tablesubhead{Frequencies}
-%  \unitinfo{hertz} & \csindex{Hz} \\
-%  \unitinfo{millihertz} & \csindex{mHz} \\
-%  \unitinfo{kilohertz} & \csindex{kHz} \\
-%  \unitinfo{megahertz} & \csindex{MHz} \\
-%  \unitinfo{gigahertz} & \csindex{GHz} \\
-%  \unitinfo{terahertz} & \csindex{THz} \\
-%
-%  \tablesubhead{Potentials}
-%  \unitinfo{millivolt} & \csindex{mV} \\
-%  \unitinfo{kilovolt} & \csindex{kV} \\
-%
-%  \tablesubhead{Energies}
-%  \unitinfo{kilojoule}  & \csindex{kJ}\\
-%  \unitinfo{electronvolt} & \csindex{eV} \\
-%  \unitinfo{millielectronvolt} & \csindex{meV} \\
-%  \unitinfo{kiloelectronvolt} & \csindex{keV} \\
-%  \unitinfo{megaelectronvolt} & \csindex{MeV} \\
-%  \unitinfo{gigaelectronvolt} & \csindex{GeV} \\
-%  \unitinfo{teraelectronvolt} & \csindex{TeV} \\
-%  \unitinfo{kilowatthour} & \cs{kWh} \\
-%
-%  \tablesubhead{Powers}
-%  \unitinfo{milliwatt} \\
-%  \unitinfo{kilowatt} \\
-%  \unitinfo{megawatt} \\
-%
-%  \tablesubhead{Capacitances}
-%  \unitinfo{femtofarad} \\
-%  \unitinfo{picofarad} \\
-%  \unitinfo{nanofarad} \\
-%  \unitinfo{microfarad} \\
-%  \unitinfo{millifarad} \\
-%
-%  \tablesubhead{Resistances}
-%  \unitinfo{kilohm} \\
-%  \unitinfo{megohm} \\
-%  \unitinfo{gigaohm} \\
-%  \unitinfo{millisiemens} \\
-%
-%  \tablesubhead{Forces}
-%  \unitinfo{millinewton} \\
-%  \unitinfo{kilonewton} \\
-%
-%  \tablesubhead{Other units}
-%  \unitinfo{hectopascal} \\
-%  \unitinfo{megabecquerel} \\
-%  \unitinfo{millisievert} \\
-%\end{longtable}
-%
-%\subsection{Defining new units}
-%\DescribeMacro{\newunit}
-%\DescribeMacro{\renewunit}
-%\DescribeMacro{\provideunit}
-% New units are produced using the \cs{newunit} macro.  This works as
-% might be expected:
-% \cs{newunit}\oarg{options}\marg{unit}\marg{symbol}, where
-% \meta{symbol} can contain literal values, other units, multiple
-% prefixes, powers and \cs{per}.  The \meta{options} argument can be
-% any suitable options, and applies the specific unit macro only. The
-% most obvious example for using this macro is the \cs{degree}
-% unit.\footnote{Although the \cs{ang} macro is preferred for this
-% job.}  The (first) optional argument to \cs{SI} and \cs{si} can be
-% used to override the settings for the unit.  The \cs{renewunit} and
-% \cs{provideunit} macros take the same arguments.
-%\begin{LaTeXexample}
-%  \SI{3.1415}{\degree}\\
-%  \newunit[valuesep=none]{\oddunit}{XXX}
-%  \SI{12345}{\oddunit}
-%  \SI[valuesep=thick]{67890}{\oddunit}
-%\end{LaTeXexample}
-%
-% As with the \LaTeX\ commands \cs{newcommand}, \etc, the choice of
-% \cs{newunit}, \cs{renewunit} or \cs{provideunit} depends on the
-% presence of an existing definition.  While \cs{newunit} should be
-% used when a unit has not been previously defined, \cs{renewunit}
-% will issue a warning if the named unit does not already exist.
-% \cs{provideunit} defines the unit if it does not exist, and
-% otherwise does nothing at all.  The same behaviour is seen with
-% \cs{providepower} and \cs{provideprefix} (\latin{vide infra}).
-%
-% Output that is only valid in maths mode requires \cs{ensuremath},
-% text-only input requires \cs{text}.  In the example below,
-% \cs{mathnormal} is used to force the font choice only for the
-% single character.\footnote{The \cs{mathrm} font used for this
-% document has an ``\ss'' at the $\pi$ position.}
-%\begin{LaTeXexample}
-%  \newunit{\SIpi}{\ensuremath{\mathnormal{\pi}}}
-%  \SI{10}{\metre\per\SIpi\squared}
-%\end{LaTeXexample}
-%
-%\DescribeMacro{\newpower}
-%\DescribeMacro{\renewpower}
-%\DescribeMacro{\providepower}
-% Powers are defined:
-% \cs{newpower}\ofixarg{post}\marg{power}\marg{num}. Here,
-% \meta{power} is the name of the power macro and \meta{num} is the
-% (positive) number it represents.  The later argument is always
-% processed internally by \cs{num}, but \emph{must} be a number.
-% Giving the optional argument \opt{post} indicates to the package
-% that the power will come after the unit it applies to; by default
-% it is assumed that it will come before.
-%\begin{LaTeXexample}
-%  \newpower{\quartic}{4}
-%  \newpower[post]{\totheforth}{4}\\
-%  \si{\kilogram\totheforth}\\
-%  \si{\quartic\metre}
-%\end{LaTeXexample}
+%    \multicolumn{3}{r}{\emph{Continued on next page}} \\
+%  }
+%  \tablelasttail{\bottomrule}
+%  \begin{xtabular}{lcc}
+%      \DescribeNamedUnit{femtogram}{fg} \\
+%      \DescribeNamedUnit{picogram}{pg}  \\
+%      \DescribeNamedUnit{nanogram}{ng}  \\
+%      \DescribeNamedUnit{microgram}{ug} \\
+%      \DescribeNamedUnit{milligram}{mg} \\ 
+%      \DescribeNamedUnit{gram}{g}       \\ 
+%      \DescribeNamedUnit{kilogram}{kg}  \\
+%      \DescribeNamedUnit{atomic mass unit}{amu} \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{picometre}{pm}  \\
+%      \DescribeNamedUnit{nanometre}{nm}  \\
+%      \DescribeNamedUnit{micrometre}{um} \\
+%      \DescribeNamedUnit{millimetre}{mm} \\
+%      \DescribeNamedUnit{centimetre}{cm} \\
+%      \DescribeNamedUnit{decimetre}{dm}  \\
+%      \DescribeNamedUnit{kilometre}{km}  \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{attosecond}{as}  \\
+%      \DescribeNamedUnit{femtosecond}{fs} \\
+%      \DescribeNamedUnit{picosecond}{ps}  \\
+%      \DescribeNamedUnit{nanosecond}{ns}  \\
+%      \DescribeNamedUnit{microsecond}{us} \\
+%      \DescribeNamedUnit{millisecond}{ms} \\
+%      \DescribeNamedUnit{second}{s}       \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{femtomole}{fmol} \\
+%      \DescribeNamedUnit{picomole}{pmol}  \\
+%      \DescribeNamedUnit{nanomole}{nmol}  \\
+%      \DescribeNamedUnit{micromole}{umol} \\
+%      \DescribeNamedUnit{millimole}{mmol} \\
+%      \DescribeNamedUnit{kilomole}{kmol}  \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{picoampere}{pA}  \\
+%      \DescribeNamedUnit{nanoampere}{nA}  \\
+%      \DescribeNamedUnit{microampere}{uA} \\
+%      \DescribeNamedUnit{milliampere}{mA} \\
+%      \DescribeNamedUnit{kiloampere}{kA}  \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{microlitre}{ul} \\
+%      \DescribeNamedUnit{millilitre}{ml} \\
+%      \DescribeNamedUnit{microliter}{uL} \\
+%      \DescribeNamedUnit{milliliter}{mL} \\
+%      
+%      \midrule
+%      
+%      \DescribeNamedUnit{millihertz}{mHz} \\
+%      \DescribeNamedUnit{hertz}{Hz}       \\
+%      \DescribeNamedUnit{kilohertz}{kHz}  \\
+%      \DescribeNamedUnit{megahertz}{MHz}  \\
+%      \DescribeNamedUnit{gigahertz}{GHz}  \\
+%      \DescribeNamedUnit{terahertz}{THz}  \\
+%      
+%      \midrule
+%  
+%      \DescribeNamedUnit{millivolt}{mV} \\
+%      \DescribeNamedUnit{kilovolt}{kV} \\
+%  
+%      \midrule
+%      
+%      \DescribeNamedUnit{kilojoule}{kJ}          \\
+%      \DescribeNamedUnit{electronvolt}{eV}       \\
+%      \DescribeNamedUnit{millielectronvolt}{meV} \\
+%      \DescribeNamedUnit{kiloelectronvolt}{keV}  \\
+%      \DescribeNamedUnit{megaelectronvolt}{MeV}  \\
+%      \DescribeNamedUnit{gigaelectronvolt}{GeV}  \\
+%      \DescribeNamedUnit{teraelectronvolt}{TeV}  \\
+%      \DescribeNamedUnit{kilowatt hour}{kWh}      \\
+%      
+%  \end{xtabular}
+%\end{center}  
 %
-%\DescribeMacro{\newprefix}
-%\DescribeMacro{\renewprefix}
-%\DescribeMacro{\provideprefix}
-% The standard SI powers of ten are defined by the package, and are
-% described above.  However, the user can define new prefixes with
-% \cs{newprefix}.  This has syntax
-% \cs{newunit}\ofixarg{binary}\marg{prefix}\marg{symbol}\marg{powers-ten},
-% where \meta{powers-ten} is the number of powers of ten the prefix
-% represents.  When the \opt{binary} option is given, the prefix is a
-% power of two.  For example, \cs{kilo} and \cs{kibi} are defined:
-%\begin{LaTeXexample}[noexample]
-%  \newprefix{\kilo}{k}{3}
-%  \newprefix[binary]{\kibi}{Ki}{10}
-%\end{LaTeXexample}
-%
-%\changes{v1.1}{2008/09/22}{Qualifiers introduced}
-%\DescribeMacro{\newqualifier}
-%\DescribeMacro{\renewqualifier}
-%\DescribeMacro{\providequalifier}
-% It is possible to create unit ``qualifiers'', which add subscript
-% descriptions to units.  Although not encouraged, this is sometimes
-% necessary to make the meaning clear.  No qualifiers are pre-defined
-% by \currpkg, and so the user needs to declare them using
-% \cs{newqualifier}. Currently, only subscript qualifiers can be
-% created; a more extended set of options is planned for the next
-% release of \currpkg.
-%\begin{LaTeXexample}
-%  \newqualifier{\polymer}{pol}
-%  \newqualifier{\catalyst}{cat}
-%  \si{\kg\polymer\per\mole\catalyst\per\hour}
-%\end{LaTeXexample}
-%
-%\section{Ranges of numbers}
-%
-%\changes{v1.2}{2009/01/22}{Added \cs{numrange} and \cs{SIrange} for
-%  handling ranges}
-%\DescribeMacro{\numrange}
-%\DescribeMacro{\SIrange}
-% To aid the input of ranges of numbers, the macros \cs{numrange} and
-% \cs{SIrange} are available.  These both take an optional settings
-% argument, then two numbers.  The \cs{SIrange} macro then needs a 
-% unit.  Depending on package settings, the phrase for the range and
-% the repetition of units can be altered.
-%\begin{LaTeXexample}
-%  \numrange{1}{10}\\
-%  \numrange[tophrase=dash]{0.4}{0.6}\\
-%  \SIrange{1.0}{1.4}{\metre}\\
-%  \SIrange[tophrase=dots]{12}{15}{\pascal}\\
-%  \SIrange[repeatunits=false]
-%    {44}{45}{\kilo\gram}\\
-%\end{LaTeXexample}
-%
-%\section{Specialist units}
-% In some subject area, there are units which are in common use even
-% though they are outside of the SI system.  Unlike the units
-% discussed earlier, these specialist units are not loaded by
-% default.  In each case, they should be requested with the option
-% \opt{alsoload=\meta{name}}.
-%
-%\subsection{Binary units (\opt{binary})\label{sec:binary}}
 %\DescribeMacro{\bit}
 %\DescribeMacro{\byte}
-% The binary prefixes, \cs{bit}, \cs{byte} (\ref{tab:binary}) are not
-% formally part of the SI system. They are available by giving the
-% \opt{alsoload=binary} option.
-%\begin{LaTeXexample}
-%  \SI{100}{\mebi\byte}
-%\end{LaTeXexample}
+% Binary data is expressed in units of bits and bytes. These are
+% normally given prefixes which use powers of two, rather than the
+% powers of ten used by the SI prefixes. As these binary prefixes are
+% closely related to the SI prefixes, they are defined by \pkg{siunitx}
+% (\cref{tab:unit:binary}). The units \cs{bit} and \cs{byte} are
+% also available.
+%\begin{LaTeXdemo}
+%  \SI{100}{\mebi\byte} \\
+%  \SI[prefixes-as-symbols=false]{30}{\kibi\bit}
+%\end{LaTeXdemo}
+%
 %\begin{table}
-%  \caption{Binary prefixes
-%    (\opt{alsoload=binary})}
-%  \label{tab:binary}
+%  \caption{Binary prefixes \protect \\
+%  (\opt{load-configurations=binary}).}
+%  \label{tab:unit:binary}
 %  \centering
-%  \begin{tabular}{lllc}
+%  \begin{tabular}{llc>{$}l<{$}}
 %    \toprule
-%      \multicolumn{1}{c}{Prefix} &
-%      \multicolumn{1}{c}{Macro} &
-%      \multicolumn{1}{c}{Power} &
-%      Symbol \\
+%      Prefix & Macro & Symbol & \multicolumn{1}{l}{Power} \\
 %    \midrule
-%      \prefixinfo{kibi} \\
-%      \prefixinfo{mebi} \\
-%      \prefixinfo{gibi} \\
-%      \prefixinfo{tebi} \\
-%      \prefixinfo{pebi} \\
-%      \prefixinfo{exbi} \\
+%      \DescribePrefix{kibi} & 10 \\
+%      \DescribePrefix{mebi} & 20 \\
+%      \DescribePrefix{gibi} & 30 \\
+%      \DescribePrefix{tebi} & 40 \\
+%      \DescribePrefix{pebi} & 50 \\
+%      \DescribePrefix{exbi} & 60 \\
+%      \DescribePrefix{zebi} & 70 \\
+%      \DescribePrefix{yobi} & 80 \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
 %
-%\subsection{Synthetic chemistry (\opt{synchem})}
-%\DescribeMacro{\mmHg}
-%\DescribeMacro{\molar}
-%\DescribeMacro{\Molar}
-%\DescribeMacro{\torr}
-%\DescribeMacro{\dalton}
-% The \opt{synchem} file adds the common chemistry units \cs{mmHg},
-% \cs{molar}, \cs{Molar}, \cs{torr} and \cs{dalton} to \currpkg.  The
-% \cs{Molar} macro is somewhat awkward, as it can be given as either
-% ``\textsc{m}'' or ``M''.  The later is obviously easily confused
-% with the sign for the prefix mega.  By default, \currpkg uses the
-% UK default of a small-caps symbol.  The \cs{dalton} unit is defined
-% here as this name is not recognised by the various international
-% bodies: the symbol \si{\amu} is preferred.
-%\begin{LaTeXexample}
-%  \SI{1}{\Molar} HCl\\
-%  \SI{760}{\torr}\\
-%  \SI{0.01}{\mmHg}\\
-%  \SI{3.0}{\molar}\\
-%  \SI{106.42}{\dalton}
-%\end{LaTeXexample}
-%
-%\subsection{High-energy physics (\opt{h})}
-% In contrast to \pkg{hepunits}, \currpkg does not define a long list
-% of compound units for high-energy physics.\footnote{Using the
-% \opt{emulate=hepunits} option will load a file defining those.}
-% Instead, a small selection of new units are defined
-% (\ref{tab:hep}).  The mechanisms provided by \currpkg should avoid
-% the need for large numbers of abbreviations.  For example, the
-% \pkg{hepunits} \cs{MinveV} can be given as |\per\MeV| in \currpkg,
-% which requires only one more character.
+% A configuration file is also included which will use settings
+% and define macros as defined by version 1 of \pkg{siunitx}: this
+% can be accessed with the option \opt{load-configurations = version-1}.
+% This is intended to allow easy transition to version 2: users
+% should update their source to use the new interfaces and functions. 
+%
+% Users upgrading from version 1 of \pkg{siunitx} will notice that
+% the various  \enquote{specialist} units available in version 1 are
+% no longer provided as loadable options.\footnote{They are included
+% in the loaded configuration file \opt{version-1}, but this is intended
+% purely to ease transition to version 2.} These are not included in
+% version 2 as the criteria for inclusion of such units are far from
+% clear, and it is difficult to justify providing clearly non-SI 
+% units in the package. For reference, appropriate definitions for 
+% the units which where provided in version 1 are as follows.
+%\begin{LaTeXdemo}[code only]
+%  % Astronomy
+%  \DeclareSIUnit\parse{pc}
+%  \DeclareSIUnit\lightyear{ly}
+%  
+%  % Chemical engineering
+%  \DeclareSIUnit\gmol{g\text{-}mol}
+%  \DeclareSIUnit\kgmol{kg\text{-}mol}
+%  \DeclareSIUnit\lbmol{lb\text{-}mol}
+%  
+%  % Chemistry
+%  \DeclareSIUnit\molar{\mole\per\cubic\deci\metre}
+%  \DeclareSIUnit\Molar{\textsc{m}}
+%  \DeclareSIUnit\torr{torr}
+%  
+%  % Geophysics
+%  \DeclareSIUnit\gon{gon}
+%\end{LaTeXdemo} 
+%
+%\begin{LaTeXdemo}[code only]
+%  % Astronomy
+%  \DeclareSIUnit\parse{pc}
+%  \DeclareSIUnit\lightyear{ly}
+%  
+%  % Chemical engineering
+%  \DeclareSIUnit\gmol{g\text{-}mol}
+%  \DeclareSIUnit\kgmol{kg\text{-}mol}
+%  \DeclareSIUnit\lbmol{lb\text{-}mol}
+%  
+%  % Chemistry
+%  \DeclareSIUnit\molar{\mole\per\cubic\deci\metre}
+%  \DeclareSIUnit\Molar{\textsc{m}}
+%  \DeclareSIUnit\torr{torr}
+%  
+%  % Geophysics
+%  \DeclareSIUnit\gon{gon}
+%\end{LaTeXdemo} 
+% Users can use a local configuration file to make additional units
+% available on a local basis, as described in \cref{sec:config:local}.
+%
+%\subsection{Using units}
+%
+% Part of the power of \pkg{siunitx} is the ability to alter the output
+% format for units without changing the input. The behaviour of units
+% is therefore controlled by a number of options which alter either the
+% processing of units or the output directly 
+% (\cref{tab:opt:units:out}).
+% 
 %\begin{table}
-%  \caption{High-energy physics units (\opt{alsoload=hep})}
-%  \label{tab:hep}
 %  \centering
-%  \begin{tabular}{lllc}
+%  \caption{Unit output options.}
+%  \label{tab:opt:units:out}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
 %    \toprule
-%    Unit & Macro & Symbol & Abbreviation \\
-%    \midrule
-%    \addlinespace \emph{Areas} \\
-%    \unitinfo{yoctobarn} & \csindex{yb} \\
-%    \unitinfo{zeptobarn} & \csindex{zb} \\
-%    \unitinfo{attobarn} & \csindex{ab} \\
-%    \unitinfo{femtobarn} & \csindex{fb} \\
-%    \unitinfo{picobarn} & \csindex{pb} \\
-%    \unitinfo{nanobarn} & \csindex{nb} \\
-%    \addlinespace \emph{Other units} \\
-%    \unitinfo{micron} \\
-%    millirad & \csindex{mrad} & \mrad \\
-%    \unitinfo{gauss} \\
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      bracket-unit-denominator & Switch & true       \\
+%      forbid-literal-units     & Switch & false      \\
+%      inter-unit-separator     & Math   & \cs{,}     \\
+%      parse-units              & Switch & true       \\
+%      per-mode                 & Choice & reciprocal \\
+%      per-symbol               & Math   & /          \\    
+%      prefixes-as-symbols      & Switch & true       \\
+%      qualifier-mode           & Choice & subscript  \\
+%      sticky-per               & Switch & false      \\
 %    \bottomrule
 %  \end{tabular}
 %\end{table}
 %
-%\DescribeMacro{\clight}
-%\DescribeMacro{\eVperc}
-% The \opt{hep} option defines two units which are slightly unusual.
-% \cs{clight} gives \clight, which is recognised as a unit when used
-% in the appropriate circumstances. The second unit provided is
-% \cs{eVperc}, which is commonly-used and clear enough for a compound
-% definition. Notice that the value of \opt{eVcorrb} will need to be
-% adjusted when using this unit.
-%\begin{LaTeXexample}
-%  \SI[per=slash,eVcorrb=0.4ex]{4.657}{\mega\eVperc\squared}
-%\end{LaTeXexample}
-%
-%\subsection{Astronomy (\opt{astro})}
-%\DescribeMacro{\parsec}
-%\DescribeMacro{\lightyear}
-% For astronomers, the \cs{parsec} and \cs{lightyear} units are
-% available, and give the obvious results.
-%\begin{LaTeXexample}
-%  \SI{12}{\parsec}\\
-%  \SI{1}{\lightyear}
-%\end{LaTeXexample}
-%
-%
-%\subsection{Geophysics (\opt{geophys})}
-%\changes{v1.1j}{2008/12/22}{New module \opt{geophys} containing \cs{gon}
-%  unit}
-%\DescribeMacro{\gon}
-% For geophysics, the unit \cs{gon} is available.
-%\begin{LaTeXexample}
-%  \SI{12}{\gon}
-%\end{LaTeXexample}
-%
-%\subsection{Chemical engineering (\opt{chemeng})}
-%\changes{v1.2f}{2009/02/20}{New module \opt{chemeng}}
-%\changes{v1.2f}{2009/02/20}{New unit \cs{gmol}}
-%\changes{v1.2f}{2009/02/20}{New unit \cs{kgmol}}
-%\changes{v1.2f}{2009/02/20}{New unit \cs{lbmol}}
-%\DescribeMacro{\gmol}
-%\DescribeMacro{\kgmol}
-%\DescribeMacro{\lbmol}
-% For chemical engineers, the units \cs{gmol}, \cs{kgmol} and \cs{lbmol}
-% can be loaded.
-%\begin{LaTeXexample}
-%  \SI{1}{\gmol} \\
-%  \SI{5}{\kgmol} \\
-%  \SI{10}{\lbmol} \\
-%\end{LaTeXexample}
-%
-%\section{Font control}
-% Following the lead of \SIstyle, \currpkg provides control over the
-% font used to typeset output.  By default, all text is typeset using
-% the current upright serif maths font, whether the macros are given
-% in text or maths mode.  Some examples will show the effect.
-%\begin{LaTeXexample}
-%  \num{10} $\num{10}$\\
-%  \sffamily \ang{20} $\ang{20}$\\
-%  \textbf{\SI{30}{\kilo\gram}}\\
-%  \boldmath $\SI{40}{\kilo\gram}$
-%  \[ \num{50} \]
-%\end{LaTeXexample}
-%
-% In contrast, by setting \opt{obeyall}, the current font is used:
-% this may be maths or text, depending on the context.
-%\begin{LaTeXexample}
-%  \sisetup{obeyall}\\
-%  \ang{1;1;1} $\ang{1;1;1}$\\
-%  \sffamily \ang{2;2;2} $\ang{2;2;2}$\\
-%  \textbf{\ang{3;3;3}} \boldmath $\ang{3;3;3}$\\
-%  \emph{\ang{4;4;4}} \emph{$\ang{4;4;4}$}
-%  \[ \ang{5;5;5} \]
-%\end{LaTeXexample}
-%
-% Fine control of which elements of the local font are used is
-% available with the \opt{obeyfamily}, \opt{obeybold},
-% \opt{obeyitalic} and \opt{obeymode} options.
-%\begin{LaTeXexample}
-%  \sisetup{obeyfamily}\\
-%  \ang{1;1;1} $\ang{1;1;1}$\\
-%  \sffamily \ang{2;2;2} $\ang{2;2;2}$\\
-%  \sisetup{obeybold}
-%  \textbf{\ang{3;3;3}} \boldmath $\ang{3;3;3}$\\
-%  \emph{\ang{4;4;4}} \emph{$\ang{4;4;4}$}
-%  \[ \ang{5;5;5} \]
-%\end{LaTeXexample}
-%
-%\section{Package options\label{sec:options}}
-%\DescribeMacro{\sisetup}
-% The ``native'' options for the package are all given using the
-% key--value method. Most of the package options can be given both
-% when loading the package and at any point in the document.  This is
-% achieved using the \cs{sisetup} macro.
-%
-% The package options take a number of different forms.
-%\begin{itemize}
-%  \item \opt{option=\meta{bool}} Simple true/false values.  These
-%    macros all default to \opt{option=true}, meaning that giving the
-%    option name along will set the appropriate flag.
-%  \item \opt{option=\meta{choice}} Take a single item from a
-%    pre-determined list. Depending on the value, one or more
-%    internal states will be altered.  Values not on the list are
-%    ignored (with a warning).
-%  \item \opt{option=\meta{choice,literal}} If the given value is a
-%    \meta{choice}, then the internal settings for that choice are
-%    used.  Any other value is used directly.
-%  \item \opt{option=\meta{literal}} The given value is used as a
-%    literal by the package.
-%  \item \opt{option=\meta{csname}} These options expect a command
-%    sequence as a value.
-%  \item \opt{option=\meta{length}} Requires a \TeX\ length, for
-%    example \opt{0.5ex}.
-%  \item \opt{option=\meta{list}} Takes a list of one or more items,
-%    which are not determined in advance.
-%  \item \opt{option=\meta{number}} Takes a number (possibly
-%    including an exponent part).
-%\end{itemize}
+%\DescribeOption{forbid-literal-units}
+% Some users may prefer to completely disable the use of literal input
+% in units, for example to enforce consistency. This can be
+% accomplished by setting the \opt{forbid-literal-units} switch. With 
+% this option enabled, only macro-based units can be used in a document.
+% 
+%\DescribeOption{inter-unit-separator} 
+% The separator between each unit is stored using the 
+% \opt{inter-unit-separator} option. The standard setting is a thin 
+% space: another common choice is a centred dot. To get the correct
+% spacing it is necessary to use "{}\cdot{}" in the later case.
+%\begin{LaTeXdemo}
+%  \si{\farad\squared\lumen\candela} \\
+%  \si[inter-unit-separator={}\cdot{}]{\farad\squared\lumen\candela} 
+%\end{LaTeXdemo} 
+% 
+%\DescribeOption{per-mode}
+%\DescribeOption{per-symbol}
+%\DescribeOption{bracket-unit-denominator}
+% The handling of \cs{per} is altered using the \opt{per-mode} choice
+% option.  The standard setting is \opt{reciprocal}, meaning that 
+% \cs{per} generates reciprocal powers for units.  Setting the option
+% to \opt{fraction} uses the \cs{frac} function to typeset the positive
+% and negative powers of a unit separately. 
+%\begin{LaTeXdemo}
+%  \si{\joule\per\mole\per\kelvin} \\
+%  \si{\metre\per\second\squared} \\
+%  \si[per-mode=fraction]{\joule\per\mole\per\kelvin} \\
+%  \si[per-mode=fraction]{\metre\per\second\squared} 
+%\end{LaTeXdemo}
+% The closely-related \opt{reciprocal-positive-first} setting acts in 
+% the same way but places all of the positive powers before any negative
+% ones.
+%\begin{LaTeXdemo}
+%  \si{\ampere\per\mole\second} \\
+%  \si[per-mode = reciprocal-positive-first]
+%    {\ampere\per\mole\second}
+%\end{LaTeXdemo}
+% It is possible to use a symbol (usually \texttt{/}) to separate the
+% two parts of a unit by setting \opt{per-mode} to \opt{symbol}; the 
+% symbol used is stored using the setting \opt{per-symbol}. This method
+% for displaying units can be ambiguous, and so brackets are added 
+% unless \opt{bracket-unit-denominator} is set to \opt{false}.
+% Notice that \opt{bracket-unit-denominator} only applies when
+% \opt{per-mode} is set to \opt{symbol} or \opt{symbol-or-fraction}.
+% The output for \opt{per-symbol} is always made in math mode, and so
+% \cs{text} will be needed to print textual information.
+%\begin{LaTeXdemo}
+%  \sisetup{per-mode = symbol}%
+%  \si{\joule\per\mole\per\kelvin} \\
+%  \si{\metre\per\second\squared} \\
+%  \si[per-symbol = \text{~div~}]{\joule\per\mole\per\kelvin} \\
+%  \si[bracket-unit-denominator = false]{\joule\per\mole\per\kelvin}
+%\end{LaTeXdemo}
+% The often-requested (but mathematically invalid) 
+% \opt{repeated-symbol} option is also available to repeat the symbol 
+% for each \cs{per}.
+%\begin{LaTeXdemo}
+%  \si[per-mode=repeated-symbol]{\joule\per\mole\per\kelvin}
+%\end{LaTeXdemo}
+% Finally, it is possible for the behaviour of the \cs{per} function
+% to depend on the surrounding environment. Setting the option to
+% \opt{symbol-or-fraction}, causes the same behaviour as
+% \opt{symbol} when the surroundings are in line, and the same 
+% behaviour as \opt{fraction} when in a display context.
+%\begin{LaTeXdemo}
+%  \sisetup{per-mode = symbol-or-fraction}%
+%  \( \si{\joule\per\mole\per\kelvin} \) 
+%  \[ \si{\joule\per\mole\per\kelvin} \]
+%     \si{\joule\per\mole\per\kelvin} 
+%\end{LaTeXdemo}
+% 
+%\DescribeOption{sticky-per}
+% By default, \cs{per} applies only to the next unit
+% given.\footnote{This is the standard method of reading units in
+% English: for example, \si{\joule\per\mole\per\kelvin} is pronounced
+% \enquote{joules per mole per kelvin}.}  By setting the 
+% \opt{sticky-per} flag, this behaviour is changed so that \cs{per} 
+% applies to all subsequent units.
+%\begin{LaTeXdemo}
+%  \si{\pascal\per\gray\henry} \\
+%  \si[sticky-per]{\pascal\per\gray\henry}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{qualifier-mode}
+% Unit qualifiers can be printed in three different formats, set by the
+% \opt{qualifier-mode} option. The standard setting is \opt{subscript},
+% while the options \opt{brackets} and \opt{space} are also possible.
+% With the last settings, powers can lead to ambiguity and are 
+% automatically detected and brackets added as appropriate.
+%\begin{LaTeXdemo}
+%  \si{\kilogram\polymer\squared\per\mole\catalyst\per\hour} \\
+%  \si[qualifier-mode=brackets]
+%    {\kilogram\polymer\squared\per\mole\catalyst\per\hour} \\
+%  \si[qualifier-mode=space]
+%    {\kilogram\polymer\squared\per\mole\catalyst\per\hour} 
+%\end{LaTeXdemo}
+%
+%\DescribeOption{prefixes-as-symbols}
+% The unit prefixes (\cs{kilo}, \emph{etc}.) are normally given as 
+% letters. However, the package can convert these into numerical powers.
+% This is controlled by the \opt{prefixes-as-symbols} switch option.
+% This correctly deals with the kilogram, which is a base unit even
+% though it involves a prefix.
+%\begin{LaTeXdemo}
+%  \si{\milli\litre\per\mole\deci\ampere} \\
+%  \SI{10}{\kilo\gram\squared\deci\second} \\
+%  \si[prefixes-as-symbols=false]{\milli\litre\per\mole\deci\ampere} \\
+%  \SI[prefixes-as-symbols=false]{10}{\kilo\gram\squared\deci\second}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{parse-units}
+% Normally, \pkg{siunitx} is used with the unit parse enabled, and
+% only prints units directly if there is literal input. However, if
+% the input is known to be essentially consistent and high performance
+% is desired, then the parser can be turned off using the
+% \opt{parse-units} switch.
+%\begin{LaTeXdemo}
+%  \SI{300}{\MHz} \\
+%  \SI[parse-units = false]{300}{\MHz}
+%\end{LaTeXdemo}
+%
+%\subsection{Numbers with units}
+%
+% Some options apply to the combination of units and numbers, rather
+% than to units or numbers alone (\cref{tab:opt:units:numbers}).
+% 
+%\begin{table}
+%  \centering
+%  \caption{Options for numbers with units.}
+%  \label{tab:opt:units:numbers}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
+%    \toprule
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      allow-number-unit-breaks & Switch & false    \\
+%      list-units               & Choice & repeat   \\
+%      multi-part-units         & Choice & brackets \\
+%      number-unit-separator    & Math   & \cs{,}   \\
+%      product-units            & Choice & repeat   \\
+%      range-units              & Choice & repeat   \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
 %
-% The package has a large range of options, to allow full control of
-% the various features of the package.  These control differing
-% aspects of the package, and are given below in groups based on
-% function.  Where the key has a default value, it is given in bold.
+%\DescribeOption{allow-number-unit-breaks}
+% Usually, the combination of a number and unit is regarded as a single
+% mathematical entity which should not be split across lines. However,
+% there are cases (very long units, narrow columns, \emph{etc}.) where 
+% breaks may be needed. This can be turned on using the 
+% \opt{allow-number-unit-breaks} option.
+%\begin{LaTeXdemo}
+%  \begin{minipage}{2.55 cm}
+%    % Gives an underfull hbox
+%    Some filler text \SI{10}{\metre} \\
+%    \sisetup{allow-number-unit-breaks}
+%    Some filler text \SI{10}{\metre} 
+%  \end{minipage}    
+%\end{LaTeXdemo}
+%
+%\DescribeOption{number-unit-separator}
+% The separator between the number and unit is set using the 
+% \opt{number-unit-separator} option. This is always printed in math
+% mode, and so anything which must be printed as text should be placed
+% inside a \cs{text} macro.
+%\begin{LaTeXdemo}
+%  \SI{2.67}{\farad} \\
+%  \SI[number-unit-separator=\text{~}]{2.67}{\farad} \\
+%  \SI[number-unit-separator=]{2.67}{\farad} 
+%\end{LaTeXdemo}
+%
+%\DescribeOption{multi-part-units}
+% When a number has multiple parts (such as a separate uncertainty) then
+% the unit must apply to all parts of the number. How this is shown is
+% controlled using the \opt{multi-part-units} options. The standard
+% setting is \opt{brackets}, which will place the entire numerical part
+% in brackets and use a single unit symbol. Alternative options are
+% \opt{repeat} (print the unit for each part of the number) and
+% \opt{single} (print only one unit symbol: mathematically incorrect).
+%\begin{LaTeXdemo}
+%  \sisetup{separate-uncertainty}%
+%  \SI{12.3(4)}{\kilo\gram} \\
+%  \SI[multi-part-units = brackets]{12.3(4)}{\kilo\gram} \\
+%  \SI[multi-part-units = repeat]{12.3(4)}{\kilo\gram}   \\
+%  \SI[multi-part-units = single]{12.3(4)}{\kilo\gram}   
+%\end{LaTeXdemo}
+% It is important to notice that numbers with units are not affected by
+% the setting of \opt{bracket-numbers}, which applies to \enquote{pure}
+% numbers only. For example:
+%\begin{LaTeXdemo}
+%  \sisetup{separate-uncertainty,bracket-numbers = false}%
+%  \num{1.234(5)e-4} \\
+%  \SI{1.234(5)e-4}{\metre}   
+%\end{LaTeXdemo}
+% The reason is that the requirements to bracket values with units are
+% fundamentally different from those for numbers alone. Some combinations
+% which are mathematically valid in the absence of a unit become invalid
+% when a unit is present.
+%
+%\DescribeOption{product-units}
+% When a product of values is given, the resulting units can be 
+% displayed in a number of ways, set using the \opt{product-units}
+% option. The standard setting is \opt{repeat}, which prints one
+% unit symbol for each numbers. Alternatives are \opt{brackets},
+% \opt{brackets-power}, \opt{power}, \opt{repeat} and \opt{single}.
+% This option does not affect the application of brackets for each
+% number within the product list: it only sets those around the
+% entire list.
+%\begin{LaTeXdemo}
+%  \SI{2 x 3 x 4}{\metre} \\ 
+%  \SI[product-units = brackets]{2 x 3 x 4}{\metre}       \\
+%  \SI[product-units = brackets-power]{2 x 3 x 4}{\metre} \\
+%  \SI[product-units = power]{2 x 3 x 4}{\metre}          \\
+%  \SI[product-units = repeat]{2 x 3 x 4}{\metre}         \\
+%  \SI[product-units = single]{2 x 3 x 4}{\metre}         
+%\end{LaTeXdemo}
+%
+%\DescribeOption{list-units}
+%\DescribeOption{range-units}
+% The \opt{list-units} and \opt{range-units} options determines how 
+% the \cs{SIlist} and\cs{SIrange} function displays units, respectively.
+% The standard setting for both is \opt{repeat}, where each number will
+% be printed with a unit. Alternatives are \opt{brackets} and 
+% \opt{single}. Any brackets needed on individual numbers within a 
+% product are controlled by the \opt{brackets-numbers} option
+% (\emph{i.e}.~they are treated as pure numbers).
+% These options do not affect the application of brackets for each
+% number within the list or range: they only sets those around the
+% entire group.
+%\begin{LaTeXdemo}
+%  \SIlist{2;4;6;8}{\tesla} \\ 
+%  \SIlist[list-units = brackets]{2;4;6;8}{\tesla} \\
+%  \SIlist[list-units = repeat]{2;4;6;8}{\tesla} \\
+%  \SIlist[list-units = single]{2;4;6;8}{\tesla} \\
+%  \SIrange{2}{4}{\degreeCelsius} \\ 
+%  \SIrange[range-units = brackets]{2}{4}{\degreeCelsius} \\
+%  \SIrange[range-units = repeat]{2}{4}{\degreeCelsius} \\
+%  \SIrange[range-units = single]{2}{4}{\degreeCelsius}
+%\end{LaTeXdemo}
 %
-%\subsection{Font family and style}
-% The font used when typesetting material can be tightly controlled
-% using \currpkg.  A number of options affect how the package matches
-% the surrounding font, and the font families used to achieve this.
-% The default is to use the current upright maths serif font with no
-% variation.
+%\subsection{Tabular material}
 %
-%\DescribeOption{mode}
-%\DescribeOption{textmode}
-%\DescribeOption{valuemode}
-%\DescribeOption{unitmode}
-%\DescribeOption{obeymode}
-% The output of \currpkg can occur using either text or maths mode.
-% The package option \opt{mode} determines which is used: valid
-% options are \defaultopt{maths} and \opt{text}.\footnote{Here and in
-% all other cases, either UK or US spelling may be used.  Thus
-% \opt{mode=maths} or \opt{mode=math} have exactly the same effect.}
-% The shortcut \opt{textmode} is provided for setting \opt{mode=text}
-% quickly. Further refinement is possible using the \opt{valuemode}
-% and \opt{unitmode} options.  These apply to numbers (the output of
-% \cs{num} and the first mandatory argument of \cs{SI}) and units
-% (all other output), respectively. By setting the \opt{obeymode}
-% flag, the package will use the local typesetting mode (maths or
-% text).
-%
-%\DescribeOption{obeyall}
-%\DescribeOption{obeyfamily}
-%\DescribeOption{obeybold}
-%\DescribeOption{obeyitalic}
-% The detection and matching of surrounding text can be controlled
-% using a number of Boolean package options. \opt{obeyall} turns on
-% all of the detection.  Thus output with \opt{obeyall} in force will
-% always match the local text appearance.  \opt{obeyfamily} instructs
-% the package on detecting the surrounding font family (Roman, sans
-% serif, fixed width), but does not detect bold or italic.
-% \opt{obeybold} detects the local bold setting, whilst
-% \opt{obeyitalic} picks up italic fonts.
-%
-% Bold detection is influenced by the value of \opt{inlinebold},
-% which takes values \defaultopt{text} and \opt{maths}.  The package
-% can detect the local value of bold for either the surrounding text,
-% or the surrounding inline (|$|\ldots|$|) maths.  The
-% \opt{obeyitalic} option does \emph{not} have the same facility
-% (maths is italic anyway).
-%
-%\DescribeOption{mathsrm}
-%\DescribeOption{mathssf}
-%\DescribeOption{mathstt}
-%\SpecialOptionIndex{mathrm}
-%\SpecialOptionIndex{mathsf}
-%\SpecialOptionIndex{mathtt}
-%\DescribeOption{textrm}
-%\DescribeOption{textsf}
-%\DescribeOption{texttt}
-% The font commands used by the package to achieve the above are all
-% available for user modification.  The options \opt{mathsrm},
-% \opt{mathssf} and \opt{mathstt} hold the command sequences used in
-% maths mode,\footnote{These can also be set using \opt{mathrm},
-% \opt{mathsf} and \opt{mathtt}} while \opt{textrm}, \opt{textsf} and
-% \opt{texttt} do the same for text mode.  By default, these contain
-% the obvious command names, for example \opt{mathsrm=mathrm} and
-% \opt{texttt=ttfamily}.  However, they can be set at will: the macro
-% names indicate the nature of the surrounding text detected.  For
-% example, the value of \opt{mathssf} is used in maths mode when the
-% surrounding text is sans serif.
-%
-%\SpecialOptionIndex{valuemathsrm}
-%\SpecialOptionIndex{valuemathssf}
-%\SpecialOptionIndex{valuemathstt}
-%\SpecialOptionIndex{valuemathrm}
-%\SpecialOptionIndex{valuemathsf}
-%\SpecialOptionIndex{valuemathtt}
-%\SpecialOptionIndex{unitmathsrm}
-%\SpecialOptionIndex{unitmathssf}
-%\SpecialOptionIndex{unitmathstt}
-%\SpecialOptionIndex{valuetextrm}
-%\SpecialOptionIndex{valuetextsf}
-%\SpecialOptionIndex{valuetexttt}
-%\SpecialOptionIndex{valuetextrm}
-%\SpecialOptionIndex{valuetextsf}
-%\SpecialOptionIndex{valuetexttt}
-%\SpecialOptionIndex{unittextrm}
-%\SpecialOptionIndex{unittextsf}
-%\SpecialOptionIndex{unittexttt}
-% Each of the font options can be given separately for the contents
-% of numbers and units.  The option names include \opt{value} or
-% \opt{unit} before the mode name.  For example, the \opt{mathsrm}
-% option may be split into \opt{valuemathsrm} and \opt{unitmathsrm}.
-%
-%\DescribeOption{detectdisplay}
-% The font detection system can treat displayed mathematical content
-% in two ways.  This is controlled by the \opt{detectdisplay} option.
-% When set to \defaultopt{true}, display mathematics is treated
-% independently from the body of the document.  Thus the local
-% \emph{maths} font is checked for matching.  In contrast, when set
-% to \opt{false}, display material is treated with the current
-% running text font.
-%\begin{LaTeXexample}
-%  \sffamily
-%  Some text
-%  \sisetup{obeyall}
-%  \[ x = \SI{1.2e3}{\kg\kelvin\candela} \]
-%  More text
-%  \sisetup{detectdisplay=false}
-%  \[ y = \SI{3}{\metre\second\mole} \]
-%\end{LaTeXexample}
-%
-%\subsection{Spacing and separators}
-%\DescribeOption{unitsep}
-%\DescribeOption{valuesep}
-%\DescribeOption{digitsep}
-%\DescribeOption{anglesep}
-% The separators between items can all be set using options taking a
-% list of pre-defined items or a literal value.  The ``\opt{sep}''
-% options (\opt{unitsep}, \opt{valuesep}, \opt{digitsep} and
-% \opt{anglesep}) all recognise \opt{thin}, \opt{medium}, \opt{med},
-% \opt{thick}, \opt{space}, \opt{cdot}, \opt{times}, \opt{tightcdot},
-% \opt{tighttimes}, \opt{fullstop}, \opt{stop}, \opt{period} and
-% \opt{none}.  The named spaces are the normal maths separations,
-% with \opt{space} representing a full (non-breakable text) space,
-% and with the obvious meanings for \opt{cdot} and \opt{times}.  The
-% \opt{tight} variants reduce the spacing available. Three possible
-% values are provided for ``|.|'', and \opt{none} yields no space at
-% all. In all cases, other values are treated literally and are
-% typeset in maths mode.  The default value is \defaultopt{thin} for
-% all separations except \opt{anglesep}, which is set to
-% \defaultopt{none}.
-%
-%\DescribeOption{unitspace}
-%\DescribeOption{errspace}
-% The \opt{unitspace} and \opt{errspace} options again take a list
-% or literal value, but only the ``real'' spaces \opt{thin},
-% \opt{medium}, \opt{med}, \opt{thick}, \opt{space} and \opt{none}
-% are recognised in the list. The \opt{unitspace} option controls the
-% output generated by an explicit space (|~|) inside a unit macro,
-% while \opt{errspace} is used to separate a bracketed error from the
-% main number.
-%
-%\subsection{Number formatting}
-%\DescribeOption{numdigits}
-%\DescribeOption{numdecimal}
-%\DescribeOption{numdiv}
-%\DescribeOption{numexp}
-%\DescribeOption{numsign}
-%\DescribeOption{numaddn}
-%\DescribeOption{numgobble}
-% There are two groups of options for formatting numbers.  The first
-% group all begin with ``\opt{num}'', and take literal values used by
-% the package to parse numbers.  \opt{numdigits} contains the valid
-% number symbols (\defaultopt{0123456789}), with \opt{numdecimal}
-% containing the decimal markers (\defaultopt{.,}).  As in the
-% \numprint package, \opt{numexp} (the list of exponent markers)
-% recognises \defaultopt{deDE} as valid by default.  \opt{numsign}
-% contains the sign markers for numbers
-% (\defaultopt{+-\cs{pm}\cs{mp}}).  \opt{numdiv} holds the division
-% marker in numbers (\defaultopt{/}). \opt{numaddn} and \opt{numgobble}
-% both control which other characters do not give an error when present
-% in a number.  \opt{numaddn} contains valid characters which should be
-% included in the final output ``as is'', whereas \opt{numgobble} lists
-% the characters that are completely ignored.  In all cases, the
-% content of the options is a simple string, for example
-% \opt{numdigits=1234567890}.
-%
-%\DescribeOption{decimalsymbol}
-%\DescribeOption{digitsep}
-%\DescribeOption{sepfour}
-% The second group of number options control the output of numbers
-% after parsing. The symbol used by \currpkg as a decimal marker is
-% set by the \opt{decimalsymbol} option, which can take a list of
-% choices or a literal.  The valid choices here are
-% \defaultopt{fullstop}, \opt{comma}, \opt{cdot} and
-% \opt{tightcdot}.\footnote{\opt{fullstop} also has aliases
-% \opt{stop} and \opt{period}.}  Notice that this does not have to
-% agree with the input marker.  The other separator for numerical
-% output is the division of digits into groups of three.  The result
-% is dependent on two options.  The previously-described
-% \opt{digitsep} option controls the spacing added between groups of
-% three numbers.  For numbers consisting of exactly four digits, the
-% \opt{sepfour} Boolean option controls whether separation occurs in
-% these cases.  The default is \defaultopt{false}.
-%\begin{LaTeXexample}
-%  \num{1234}\\
-%  \num[sepfour]{1234}
-%\end{LaTeXexample}
-%
-%\DescribeOption{seperr}
-%\DescribeOption{numopenerr}
-%\DescribeOption{numcloseerr}
-% For numbers given with an error [\eg \num{1.23(4)}], the package
-% can separate out the error part, to give for example
-% \num[seperr]{1.23(4)}.  This behaviour is activated by the
-% \opt{seperr} option, and requires that \opt{numopenerr} and
-% \opt{numcloseerr} contain the left- and right-hand delimiters for
-% the error [defaults \opt{numopenerr=(} and \opt{numcloseerr=)}].
-%\begin{LaTeXexample}
-%  \sisetup{seperr}\\
-%  \num{1.234(5)}\\
-%  \num{1.234(5)e6}
-%\end{LaTeXexample}
-%\DescribeOption{trapambigerr}
-%\DescribeOption{openerr}
-%\DescribeOption{closeerr}
-%\DescribeOption{tightpm}
-% If the number has an exponent, or if units are not repeated, then
-% the result can be considered ambiguous.  By default, the package
-% adds the markers stored in \opt{openerr} and \opt{closeerr} to
-% remove the ambiguity; the options have the same default values as
-% the input error markers.  Detection of a potentially-ambiguous
-% error is controlled by the \opt{trapambigerr} option, although for
-% numbers with units the \opt{repeatunits} option is also important.
-% The spacing around the $\pm$ sign is normally set by \TeX. However,
-% using the \opt{tightpm} option will cause this to be reduced to a
-% minimum.
-%\begin{LaTeXexample}
-%  \sisetup{seperr}\\
-%  \num[trapambigerr=false]{1.234(5)e6}\\
-%  \SI{1.234(5)}{\metre}\\
-%  \sisetup{repeatunits=false}
-%  \SI{1.234(5)}{\metre}\\
-%  \SI[trapambigerr=false]{1.234(5)}{\metre}\\
-%  \num[tightpm]{1.234(5)}
-%\end{LaTeXexample}
-%
-%\DescribeOption{numprod}
-%\DescribeOption{repeatunits}
-% The number processor can recognise products in the numerical input;
-% the symbols used for products are stored in \opt{numprod}, with the
-% default value of ``\opt{x}''.  By default, the \cs{SI} macro will
-% repeat the units for a number given in this way.  This behaviour is
-% altered  by the \opt{repeatunits} option, which takes the values
-% \defaultopt{true}, \opt{false} and \opt{power}.  The later applies
-% only when providing multiplied numbers with units, and converts the
-% unit to the appropriate power rather than repeating the
-% units.\footnote{This is a very simply option: do not expect it to
-% work with anything except areas and volumes.} Notice that when
-% applied to errors, \opt{repeatunits} takes priority over
-% \opt{trapambigerr}.\footnote{\opt{repeatunits} also applies to the 
-% range macro \cs{SIrange}.}
-%\begin{LaTeXexample}
-%  \num{1 x 2 x 3}\\
-%  \SI{4 x 5 x 6}{\metre}\\
-%  \sisetup{repeatunits=false}
-%  \SI{1.2 x 3.4 x 5.6}{\milli\metre\cubed}\\
-%  \SI[seperr]{1.234(5)}{\metre}\\
-%  \SI[seperr,
-%    trapambigerr=false]
-%    {9.1093897(54)e-31}{\kilo\gram}\\
-%  \SI[seperr,repeatunits,
-%    trapambigerr=false]
-%    {9.1093897(54)e-31}{\kilo\gram}\\
-%  \SI[repeatunits=power]{1 x 2 x 3}{\metre}
-%\end{LaTeXexample}
-%
-%\DescribeOption{expproduct}
-%\DescribeOption{expbase}
-%\DescribeOption{allowzeroexp}
-% The formatting of exponents is controlled by \opt{expproduct} and
-% \opt{expbase}.  \opt{expproduct} sets the symbol used to indicate a
-% product for exponents (\eg the $\times$ in \num{2e2}), while the
-% value of \opt{expbase} sets the power used (the \num{10} in the
-% example).  Both options accept a very short list of options:
-% \defaultopt{times}, \opt{tighttimes}, \opt{cdot} and
-% \opt{tightcdot} for the product, and \defaultopt{ten} and \opt{two}
-% for the power.\footnote{The \opt{tighttimes} and \opt{tightcdot}
-% options give the rather questionable results:
-% \num[expproduct=tighttimes]{1e2} and
-% \num[expproduct=tightcdot]{1e2}, as opposed to \num{1e2} and
-% \num[expproduct=cdot]{1e2}.} Other choices are used literally. Also
-% relevant to exponent processing is the \opt{allowzeroexp} option.
-% By default, the package will suppress a zero exponent, but setting
-% the flag will allow the output of \num[allowzeroexp]{e0}.
-%
-%\DescribeOption{addsign}
-%\DescribeOption{sign}
-%\DescribeOption{retainplus}
-% Additions to the input can take the form of implicit signs and
-% padded zeros.  The \opt{addsign} option takes a list of potential
-% sites to add a sign: \defaultopt{none}, \opt{mantissa},
-% \opt{exponent} and \opt{both}.\footnote{Aliases are provided:
-% \opt{mant} = \opt{mantissa}, \opt{exp} = \opt{exponent}, \opt{all}
-% = \opt{true} = \opt{both}, \opt{false} = \opt{none}.}  If no sign
-% is given in the input, the setting here determines if one is added.
-% The sign to add is stored in \opt{sign}, which takes the list of
-% choices \defaultopt{plus}, \opt{minus}, \opt{pm} and \opt{mp}, or
-% uses the input literally (in maths mode).  For positive numbers,
-% the \opt{retainplus} option causes a $+$ sign explicitly in the
-% input to be retained.  By default, the package will remove such
-% signs.
-%
-%\DescribeOption{padnumber}
-% The \opt{padnumber} option controls the addition of zeros to the
-% input, to ``pad'' the result.  The option takes a list of choices:
-% \defaultopt{leading}, \opt{trailing}, \opt{both} and
-% \opt{none}.\footnote{Aliases: \opt{all} = \opt{true} = \opt{both},
-% \opt{false} = \opt{none}.}  No additional precision is added by
-% this option; integer input will not add a decimal point.
-%\begin{LaTeXexample}
-%  \num[padnumber=leading]{.1}\\
-%  \num[padnumber=leading]{2.}\\
-%  \num[padnumber=trailing]{3.}\\
-%  \num[padnumber=both]{4.}\\
-%  \num[padnumber=both]{.5}\\
-%  \num[padnumber=both]{6}\\
-%  \num[padnumber=none]{7.}\\
-%  \num[padnumber=none]{.8}
-%\end{LaTeXexample}
-%
-%\DescribeOption{fixdp}
-%\DescribeOption{dp}
-% In contrast to the \opt{padnumber} option, the package can alter
-% the precision of the input number if the \opt{fixdp} option is set.
-% The \opt{fixdp} option will fix the decimal places of the output to
-% the number stored in the \opt{dp} option.  The later should be a 
-% positive integer or zero.
-%\begin{LaTeXexample}
-%  \sisetup{fixdp,dp=3}
-%  \num{1}\\
-%  \num{53.9}\\
-%  \num{4.56783}\\
-%  \num{-1.2942}\\
-%  \num{-1.2959}\\
-%  \num{9.9999}\\
-%  \num{2.1264e90}\\
-%  \num[dp=0]{12.345}
-%\end{LaTeXexample}
-%
-%\DescribeOption{fixsf}
-%\changes{v1.1}{2008/08/22}{New \opt{fixsf} option}
-%\DescribeOption{sf}
-%\changes{v1.1}{2008/08/22}{New \opt{sf} option}
-% In contrast to the \opt{dp} option, the \opt{fixsf} and \opt{sf}
-% options control the number of significant figures in the output.
-% This never adds extra digits to the output, as significant figures
-% are concerned with accuracy.
-%\begin{LaTeXexample}
-%  \sisetup{fixsf,sf=3}
-%  \num{1}\\
-%  \num{53.9}\\
-%  \num{4.56783}\\
-%  \num{-1.2942}\\
-%  \num{-1.2959}\\
-%  \num{9.9999}\\
-%  \num{2.1264e90}\\
-%  \num{773322}
-%\end{LaTeXexample}
-%
-%\DescribeOption{tophrase}
-% When using the range macros \cs{numrange} and \cs{SIrange}, the phrase
-% used for ``to'' is set using the option \opt{tophrase}. This can take
-% three pre-defined choices \defaultopt{to}, \opt{dots} and \opt{dash},
-% or arbitrary input in text mode.
-%\begin{LaTeXexample}
-%  \numrange{1}{10}\\
-%  \numrange[tophrase=dots]{1}{10}\\
-%  \numrange[tophrase=dash]{1}{10}\\
-%  \numrange[tophrase={{ bis }}]{1}{10}\\
-%\end{LaTeXexample}
-% Notice that any space required must be included in the phrase itself,
-% and that this may require a second set of braces.
+% Processing of material in tables obeys the same settings as described
+% for the functions already described. However, there are some settings
+% which apply only to the layout of tabular material 
+% (\cref{tab:opt:tables}).
 % 
-%\DescribeOption{trapambigrange}
-%\changes{v1.2i}{2009/04/01}{Added \opt{trapambigrange} option}
-%\DescribeOption{openrange}
-%\DescribeOption{closerange}
-% When \opt{repeatunits} is false, the \opt{trapambigrange} option 
-% controls whether brackets are added to keep unit--value agreement.
-% As with other options for trapping ambiguous output, the bracket 
-% symbols used here are stored as \opt{openrange} and \opt{closerange}.
-%\begin{LaTeXexample}
-%  \SIrange{1}{10}{\kg}\\
-%  \SIrange[repeatunits=false]{1}{10}{\kg}\\
-%  \SIrange[repeatunits=false,trapambigrange=false]
-%    {1}{10}{\kg}
-%\end{LaTeXexample}
-% Notice that any space required must be included in the phrase itself,
-% and that this may require a second set of braces.
-%
-%\subsection{Angle formatting}
-%\DescribeOption{padangle}
-%\DescribeOption{strictarc}
-% The angle formatter uses \cs{num} to format numbers: any options
-% for numbers are therefore applicable here.  The \opt{padangle}
-% option takes choices \defaultopt{small}, \opt{large}, \opt{all} and
-% \opt{none}, and controls how angles are padded when given in
-% degrees, minutes and seconds.\footnote{Aliases: \opt{all} =
-% \opt{true} = \opt{both}, \opt{false} = \opt{none}.}  When giving
-% angles as arcs (in degrees, minutes and seconds), the package can
-% detect if the correct number of semi-colons have been given. This
-% is controlled by the \opt{strictarc} option, which is a Boolean
-% switch with a \defaultopt{true} default.  With \opt{strictarc} set
-% to \opt{false}, an incomplete arc is interpreted as degrees and
-% minute, while an over-complete one will drop excess input.
-%\begin{LaTeXexample}
-%  \ang[padangle=none]{1;;}\\
-%  \ang[padangle=large]{2;;}\\
-%  \ang[padangle=small]{3;;}\\
-%  \ang[padangle=both]{;4;}\\
-%  \ang[padangle=none]{;5;5}\\
-%  \ang[strictarc=false]{1;2}\\
-%  \ang[strictarc=false]{1;2;3;4;}
-%\end{LaTeXexample}
-%
-%\DescribeOption{angformat}
-% The angle formatting system can convert between decimal angles and
-% those given as degrees, minutes and seconds.  This is controlled by
-% the \opt{angformat} option, which takes choices
-% \defaultopt{unchanged}, \opt{decimal} and
-% \opt{arc}.\footnote{Aliases: \opt{decimal} = \opt{dec}, \opt{arc} =
-% \opt{dms}, \opt{unchanged} = \opt{none}.}  When set to
-% \opt{unchanged}, nothing is done to the input.  The conversion is
-% based on \TeX\ dimensions, and is therefore limited in accuracy.
-% For this reason, the output is automatically rounded: output as a
-% decimal angle is limited to three places, and that as an arc is
-% given to a single decimal place for the seconds component.
-%\begin{LaTeXexample}
-%  $\ang{1;2;3} = \ang[angformat=dec]{1;2;3}$\\
-%  $\ang{4.56} = \ang[angformat=arc]{4.56}$
-%\end{LaTeXexample}
-%
-%\DescribeOption{astroang}
-% For astronomers, the \opt{astroang} option is provided.  This
-% moves the degrees, minutes or seconds symbol (as appropriate)
-% over the decimal marker rather than after the number.
-%\begin{LaTeXexample}
-%  \ang{1;2;3.4}\\
-%  \ang[astroang]{5;6;7.8}
-%\end{LaTeXexample}
+%\begin{table}
+%  \centering
+%  \caption{Options for tabular material.}
+%  \label{tab:opt:tables}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
+%    \toprule
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      table-align-text-post     & Switch  & true      \\
+%      table-alignment           & Choice  & \m{none}  \\
+%      table-auto-round          & Switch  & false     \\
+%      table-figures-decimal     & Integer & 2         \\
+%      table-figures-exponent    & Integer & 0         \\
+%      table-figures-integer     & Integer & 3         \\
+%      table-figures-uncertainty & Integer & 0         \\
+%      table-format              & Special & \m{none}  \\
+%      table-number-alignment    & Choice  & 
+%        center-decimal-marker \\
+%      table-parse-only          & Switch  & false     \\
+%      table-space-text-pre      & Literal & \m{empty} \\
+%      table-space-text-post     & Literal & \m{empty} \\
+%      table-sign-exponent       & Switch  & false     \\
+%      table-sign-mantissa       & Switch  & false     \\
+%      table-text-alignment      & Choice  & center    \\
+%      table-unit-alignment      & Choice  & center    \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
 %
-%\subsection{Tabular material}
-%\DescribeOption{tabnumalign}
-% Material typeset in |S| columns is processed internally by the
-% \cs{num} macro.  Thus, as with angles, the number options also
-% apply here.  The positioning of tabular material is controlled by
-% the two options \opt{tabnumalign} and \opt{tabformat}.
-% \opt{tabnumalign} takes values \defaultopt{centredecimal},
-% \opt{centre}, \opt{left} and \opt{right}.\footnote{Aliases
-% \opt{centerdecimal} = \opt{centredecimal}; \opt{center} =
-% \opt{centre}.}  When using \opt{centredecimal}, the package places
-% the decimal marker of the mantissa at the centre of the column,
-% which then grows to accommodate the widest number given.  For equal
-% numbers of digits before and after the decimal sign, this is the
-% easiest option.  The other choices use a fixed-width box to store
-% the number; the box is then aligned with the edges of the column.
-%
-%\DescribeOption{tabformat}
-% The \opt{tabformat} option sets the amount of space reserved by
-% \currpkg for the alignment box when not using the
-% \opt{centredecimal} setting of \opt{tabnumalign}.  The numerical
-% parts of \opt{tabformat} are interpreted as
-% \texttt{\meta{pre}\meta{dec}\meta{post}}; \meta{pre} and
-% \meta{post} are the number of digits before and after the decimal
-% sign, respectively.  Both signs and exponents can be included in
-% \opt{tabformat}, resulting in appropriate space being reserved. The
-% entire \opt{tabformat} input is processed using the \cs{num} macro
-% internally.  Thus the decimal and exponent signs used in
-% \opt{tabformat} are checked against \opt{numdecimal} and
-% \opt{numexp}, respectively.
-%
-%\DescribeOption{tabalignexp}
-%\DescribeOption{tabexpalign}
-%\changes{v1.1d}{2008/10/29}{Added \opt{tabexpalign} as an alias for
-%  \opt{tabalignexp}}
-% When \opt{tabformat} contains exponents, two possibilities are
-% available for alignment.  The first method is to place the exponent
-% parts so that the ``$\times 10$'' parts form a column, with
-% whitespace after shorter mantissa components.  In the second
-% method, no additional space is added after the mantissa, and the
-% exponents do no line up (\ref{tab:alignexp}).  This is controlled
-% by the \opt{tabalignexp} option, which can be set to
-% \defaultopt{true} or \opt{false}. The alias \opt{tabexpalign} is
-% available for this option.
-%\begin{LaTeXexample}[float]
+%\DescribeOption{table-parse-only}
+% The main use of the \texttt{S} column is to control the alignment of
+% the resulting output. However, it is possible to turn off alignment
+% entirely and only use the number parser of \pkg{siunitx}. This is
+% achieved using the \opt{table-parse-only} switch, as illustrated
+% in \cref{tab:S:parse}.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
 %    \centering
-%    \caption{The \opt{tabalignexp} option}
-%    \label{tab:alignexp}
-%    \sisetup{tabformat=1.3e2,tabnumalign=centre}
-%    \begin{tabular}{SS[tabalignexp=false]}
+%    \caption{Parsing without aligning in an \texttt{S} column.}
+%    \label{tab:S:parse}
+%    \begin{tabular}
+%      {
+%        S
+%        S[table-parse-only]
+%      }      
 %      \toprule
-%      {Header} & {Header} \\
+%        {Decimal-centred} &
+%        {Simple centring} \\
 %      \midrule
-%      1.2e3    & 1.2e3    \\
-%      1.234e56 & 1.234e56 \\
+%        12.345   & 12.345   \\
+%        6,78     & 6,78     \\
+%        -88.8(9) & -88.8(9) \\
+%        4.5e3    & 4.5e3    \\
 %      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\DescribeOption{tabtextalign}
-%\DescribeOption{tabunitalign}
-%\DescribeOption{tabalign}
-% Cells containing no numbers are handled by \currpkg in a manner
-% similar to \cs{multicolumn}.  The setting of \opt{tabtextalign} is
-% taken from the list \defaultopt{centre}, \opt{right} and
-% \opt{left}.\footnote{Alias \opt{centre} = \opt{center}.}  As would
-% be expected, these settings centre, right- or left-align the cell
-% contents. In |s| columns, all content is treated as input to the
-% \cs{si} macro.  The alignment of the contents relative to the cell
-% is controlled by the \opt{tabunitalign} option, which takes options
-% \defaultopt{left}, \opt{right} and \opt{centre}.  The settings for
-% \opt{tabnumalign}, \opt{tabtextalign} and \opt{tabunitalign} can be
-% set to the same value in one go with the \opt{tabalign} option.
-%
-%\DescribeOption{tabautofit}
-% The contents of table cells can automatically be rounded or
-% zero-filled to the number of decimal places given in
-% \opt{tabformat}.  This is activated by the \opt{tabautofit} Boolean
-% option. As \opt{tabformat} does not apply to columns with alignment
-% \opt{centredecimal}, \opt{tabautofit} is also inactive for these
-% columns (\ref{tab:autofit}).
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+%
+%\DescribeOption{table-number-alignment}
+% The alignment of numbers with the boundaries of the \texttt{S}
+% column is controlled using the \opt{table-number-alignment} option,
+% which takes the values \opt{center-decimal-marker}, \opt{center},
+% \opt{left} and \opt{right}. The \opt{center-decimal-marker} places the
+% decimal marker for the number at the centre of the column. This does
+% not need any information in advance, and so is the standard setting.
+% It works best for approximately symmetrical input (equal numbers of
+% digits before and after the decimal). On the other hand, the
+% \opt{center}, \opt{left} and \opt{right} options require space to be
+% reserved for the numbers, and then use this fixed space to align with
+% the edges of the column. The different alignment choices are 
+% illustrated in \cref{tab:S:align}, which uses somewhat 
+% exaggerated column headings to show the relative position of the 
+% cell contents.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
+%    \caption{Aligning the \texttt{S} column.}
+%    \label{tab:S:align}
 %    \centering
-%    \caption{The \opt{tabautofit} option}
-%    \label{tab:autofit}
-%    \sisetup{tabformat=1.3,tabnumalign=centre}
-%    % Notice the overfull hbox which results with
-%    % the first column
-%    \begin{tabular}{%
-%      S%
-%      S[tabautofit]%
-%      S[tabautofit,tabnumalign=centredecimal]}
-%      \toprule
-%      {Header} & {Header} & {Header} \\
-%      \midrule
-%      1.2    & 1.2    & 1.2    \\
-%      1.2345 & 1.2345 & 1.2345 \\
-%      \bottomrule
+%    \sisetup{
+%      table-figures-integer = 2,
+%      table-figures-decimal = 4
+%    }
+%    \begin{tabular}{
+%      S
+%      S[table-number-alignment = center]
+%      S[table-number-alignment = left]
+%      S[table-number-alignment = right]
+%    }
+%    \toprule
+%    {Some Values} & {Some Values} & {Some Values} & {Some Values} \\
+%    \midrule
+%       2.3456  &  2.3456  &  2.3456 &  2.3456 \\
+%      34.2345  & 34.2345  & 34.2345 & 34.2345 \\
+%      56.7835  & 56.7835  & 56.7835 & 56.7835 \\
+%      90.473   & 90.473   & 90.473  & 90.473  \\
+%    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\DescribeOption{tabparseonly}
-% It is possible to turn off the automatic alignment of numbers
-% while retaining the ability to parse the |S| column input.
-% Setting \opt{tabparseonly} to \opt{true} will still parse the
-% column contents, but will not align the decimal markers.  The
-% alignment of the cell is governed by \opt{tabnumalign}
-% (\ref{tab:parse}).
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+% Many of the other table options do not apply when 
+% \opt{table-number-alignment = center-decimal-marker} is set, as this 
+% mode always centres the marker at the expense of any other 
+% choices.
+%
+%\DescribeOption{table-figures-decimal}
+%\DescribeOption{table-figures-exponent}
+%\DescribeOption{table-figures-integer}
+%\DescribeOption{table-figures-uncertainty}
+% The space reserved by \pkg{siunitx} for a number is controlled by
+% two families of options. The first family cover the number of digits
+% allowed for in different parts of the number, for example
+% \opt{table-figures-integer} controls the space for integer digits in
+% the mantissa. If the number of figures is set to \num{0}, then no
+% space is reserved and some output will either be out of position
+% or not printed at all (although a warning will result). Reserving
+% space for a given part of number will automatically include space
+% for any associated items (for example the \enquote{\( \times \)} 
+% symbol for exponents).
+%\DescribeOption{table-sign-exponent}
+%\DescribeOption{table-sign-mantissa}
+% The second family of options are switches which govern whether
+% space is reserved for a sign: \opt{table-sign-exponent} and
+% \opt{table-sign-mantissa}. The effect of altering some of these
+% settings is shown in \cref{tab:S:space}.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
+%    \caption{Reserving space in \texttt{S} columns.}
+%    \label{tab:S:space}
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 2
+%    }
 %    \centering
-%    \caption{The \opt{tabparseonly} option}
-%    \label{tab:parse}
-%    \begin{tabular}{%
-%      S[tabparseonly]%
-%      S[tabparseonly,tabnumalign=left]%
-%      S[tabparseonly,tabnumalign=right]}
-%      \toprule
-%      {Header} & {Header} & {Header} \\
-%      \midrule
-%      14.2    & 14.2    & 14.2    \\
-%      1.23456 & 1.23456 & 1.23456 \\
-%      1.2e3   & 1.2e3   & 1.2e3   \\
-%      \bottomrule
+%    \begin{tabular}{
+%      S
+%      S[table-number-alignment = right]
+%      S[table-figures-uncertainty = 1]
+%      S[
+%        separate-uncertainty,
+%        table-figures-uncertainty = 1
+%      ]
+%      S[table-sign-mantissa]
+%      S[table-figures-exponent = 1]
+%      }
+%    \toprule
+%        {Values}
+%      & {Values}
+%      & {Values}
+%      & {Values}
+%      & {Values}
+%      & {Values} \\
+%    \midrule
+%       2.3  &  2.3  &  2.3(5)  &  2.3(5)  &   2.3  &  2.3e8  \\
+%      34.23 & 34.23 & 34.23(4) & 34.23(4) &  34.23 & 34.23   \\
+%      56.78 & 56.78 & 56.78(3) & 56.78(3) & -56.78 & 56.78e3 \\
+%       3,76 &  3,76 &  3,76(2) &  3.76(2) & +-3.76 &      e6 \\
+%    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\subsection{Units}
-%\DescribeOption{per}
-% Most of the unit options are concerned with the processing of named
-% units.  The processor for units given as macro names can be
-% influenced to give a variety of output formats.  The \opt{per}
-% option defines how the keyword macro \cs{per} is handled.  This
-% option takes a choice from the list \defaultopt{reciprocal},
-% \opt{slash} and \opt{fraction}.\footnote{Aliases \opt{reciprocal} =
-% \opt{rp} = \opt{power}, \opt{fraction} = \opt{frac}.}  The default
-% option uses \cs{per} to indicate reciprocal powers, whereas
-% \opt{slash} causes the package to use ``$/$'' to show division.
-%
-%\DescribeOption{fraction}
-%\DescribeOption{slash}
-% The \opt{fraction} option defines how \opt{per=fraction} is
-% interpreted.  The list of applicable values here is
-% \defaultopt{frac}, \opt{nice}, \opt{ugly} and \opt{sfrac}.  In each
-% case, the unit is typeset as a fraction, but the macro use to
-% achieve this varies. \opt{frac} uses the \TeX\ \cs{frac}, macro,
-% while \opt{nice} makes use of a \cs{nicefrac}-like method.  The
-% \opt{ugly} option uses a slash in text mode and \cs{frac} in maths
-% mode.\footnote{Similar to the \pkg{ugly} option of the
-% \pkg{nicefrac} package.}  Finally, the setting \opt{fraction=sfrac}
-% uses the \cs{sfrac} macro from the \pkg{xfrac} package, when
-% available.\footnote{\pkg{xfrac} is part of the experimental system
-% for \LaTeX3.  As it requires a number of additional packages to
-% work, \currpkg does not load \pkg{xfrac}. If it is unavailable, the
-% \opt{sfrac} setting will fall back to using \cs{nicefrac}.  See the
-% \pkg{xfrac} documentation for reasons to prefer \cs{sfrac} to
-% \cs{nicefrac}.}  The \opt{slash} option sets the symbol used when
-% \opt{per=slash} is in force.  This recognises the single keyword
-% \opt{slash}; anything else is used literally.
-%\begin{LaTeXexample}
-%  \sisetup{per=fraction}
-%  \si[fraction=frac]{\metre\per\second}\\
-%  \si[fraction=nice]{\metre\per\second}\\
-%  \si[fraction=sfrac]{\metre\per\second}\\
-%  \si[per=slash]{\metre\per\second}
-%\end{LaTeXexample}
-%
-%\DescribeOption{stickyper}
-% By default, \cs{per} applies only to the next unit
-% given.\footnote{This is the standard method of reading units in
-% English: for example, \si{\joule\per\mole\per\kelvin} is pronounced
-% ``joules per mole per kelvin''.}  By setting the \opt{stickyper}
-% flag, this behaviour is changed so that \cs{per} applies to all
-% subsequent units.\footnote{This is the behaviour in \SIunits.}
-%\begin{LaTeXexample}
-%  \si{\kilogram\per\metre\ampere}\\
-%  \si[stickyper]{\kilogram\per\metre\ampere}
-%\end{LaTeXexample}
-%
-%\DescribeOption{trapambigfrac}
-%\DescribeOption{openfrac}
-%\DescribeOption{closefrac}
-% When using \opt{per=slash}, multiple units in the denominator will
-% yield a potentially ambiguous result.  The \opt{trapambigfrac}
-% determines whether the package checks for this: this takes
-% \defaultopt{true} and \opt{false}.  When set, the contents of
-% \opt{openfrac} are inserted before the denominator, and
-% \opt{closefrac} is inserted after.
-%\begin{LaTeXexample}
-%  \sisetup{trapambigfrac,openfrac=(,closefrac=),per=slash}\\
-%  \si{\metre\per\second\per\kilogram}\\
-%  \si[trapambigfrac=false]{\metre\per\second\per\kilogram}
-%\end{LaTeXexample}
-%
-%\DescribeOption{prefixsymbolic}
-%\DescribeOption{prefixbase}
-%\DescribeOption{prefixproduct}
-% The unit prefixes (\cs{kilo}, \etc) are normally given as letters.
-% However, the package can convert these into numerical
-% powers.\footnote{Provided things are not too complex!}  This is
-% controlled by the \opt{prefixsymbolic} Boolean option, which by
-% default is \defaultopt{true}.  If \opt{prefixsymbolic} is set to
-% \opt{false}, the format of the prefix is controlled by
-% \opt{prefixbase} and \opt{prefixproduct}, which work in the same
-% way as \opt{expbase} and \opt{expproduct}.
-%
-%\DescribeOption{prespace}
-%\DescribeOption{xspace}
-%\DescribeOption{allowoptarg}
-% By default, the single unit macros (\eg \cs{metre}) add no space
-% either before or after the unit.  Setting the \opt{xspace} flag to
-% true means that the single macros are followed by the \cs{xspace}
-% command (when used outside of \cs{SI}/\cs{si}).  For users of
-% \unitsdef, the \opt{prespace} macro changes the behaviour of the
-% unit macros, so that they can immediately follow a number.  As a
-% result, the unit macros will \emph{always} be preceded by a fixed
-% space when the \opt{prespace} flag is true: this will be in
-% addition to any other space. Also relevant to users moving from
-% \unitsdef is the \opt{allowoptarg} option.  This allows single unit
-% macros to take an optional numerical argument, in the same way that
-% occurs in that package.
-%\begin{LaTeXexample}
-%  \metre is the symbol for metres\\
-%  \sisetup{xspace}
-%  No, \metre is the correct symbol\\
-%  \sisetup{prespace}
-%  30\metre\\
-%  Do not use \metre in running text\\
-%  \sisetup{allowoptarg}
-%  \metre[40]
-%\end{LaTeXexample}
-%
-%\subsection{Symbols}
-% User access to control the symbols used for \si{\ohm}, \si{\micro},
-% \si{\degree}, \si{\arcmin}, \si{\arcsec}, \si{\angstrom} and
-% \si{\celsius} is provided here. These are all literal options,
-% which are available in text and maths mode variants.  For example,
-% \opt{textmicro} is the code used for the \si{\micro} symbol in text
-% mode.  The text mode macros should be safe when forced into text,
-% and the maths ones when forced into maths.  The symbols defined in
-% this way are:
-%\newcommand*{\listsymbopt}[1]{\item \opt{#1}\SpecialOptionIndex{#1}}
-%\begin{itemize}
-%  \listsymbopt{textOmega};
-%  \listsymbopt{mathsOmega};
-%  \listsymbopt{textmu};
-%  \listsymbopt{mathsmu};
-%  \listsymbopt{textdegree};
-%  \listsymbopt{mathsdegree};
-%  \listsymbopt{textminute};
-%  \listsymbopt{mathsminute};
-%  \listsymbopt{textsecond};
-%  \listsymbopt{mathssecond};
-%  \listsymbopt{textringA};
-%  \listsymbopt{mathsringA};
-%  \listsymbopt{textcelsius};
-%  \listsymbopt{mathscelsius}.
-%\end{itemize}
-%
-%\DescribeOption{redefsymbols}
-% When \currpkg is loaded, it can check for the presence of the
-% \pkg{textcomp} and \pkg{upgreek} packages, to provide better
-% symbols for certain items. To prevent this, set the
-% \opt{redefsymbols} option \opt{false} (the default is
-% \defaultopt{true}).
-%
-%\DescribeOption{eVcorra}
-%\DescribeOption{eVcorrb}
-% The \si{\electronvolt} symbol requires some fine-tuning, and so has
-% two options of its own, both \TeX\ lengths.  \opt{eVcorra} is the
-% correction applied to the gap between ``e'' and ``V'' of the unit:
-% the default is \defaultopt{0.3ex}. \opt{eVcorrb} is the correction
-% applied to the gap between ``V'' of the unit and whatever follows;
-% the default is \defaultopt{0ex}.  The optimal value for these
-% options will depend on the current font settings.\footnote{This
-% document uses \opt{eVcorra=0.1ex}.}
-%\begin{LaTeXexample}
-%  \si[per=slash]{\electronvolt\per\metre}\\
-%  \si[per=slash,eVcorrb=0.7ex]{\electronvolt\per\metre}
-%\end{LaTeXexample}
-%
-%\subsection{Colour}
-%\DescribeOption{colourall}
-%\DescribeOption{colourunits}
-%\DescribeOption{colourvalues}
-%\SpecialOptionIndex{colorall}
-%\SpecialOptionIndex{colorunit}
-%\SpecialOptionIndex{colorvalue}
-% The package provides internal hooks for applying colour to part or
-% all of the output.  This requires the user to load the \pkg{color}
-% or \pkg{xcolor} package to support colour in the output; \currpkg
-% will ignore a colour request if support is unavailable. The Boolean
-% options \opt{colourall}, \opt{colourunits} and \opt{colourvalues}
-% are used to turn application of a given colour on or off for all
-% output, only units and only values, respectively.  All three
-% switches are available with US spelling, \eg \opt{colorall} and
-% \opt{colourall} behave in the same way.  With colour turned off, no
-% \cs{color} command is issued internally, and output follows the
-% surrounding text.
-%
-%\DescribeOption{colour}
-%\DescribeOption{unitcolour}
-%\DescribeOption{valuecolour}
-%\SpecialOptionIndex{color}
-%\SpecialOptionIndex{unitcolor}
-%\SpecialOptionIndex{valuecolor}
-% The colour names to use for colouring output are set by the
-% \opt{colour}, \opt{unitcolour} and \opt{valuecolour} options (all
-% also available with US spelling).  The \opt{colour} option
-% internally sets both \opt{unitcolour} and \opt{valuecolour}.
-%\begin{LaTeXexample}
-%  {\color{brown} Text \num{50}}\\
-%  \sisetup{colourall,colour=green}
-%  \SI{10}{\metre}\\
-%  {\color{purple} Text \num{70}}\\
-%  \sisetup{colourunits=true,colourvalues=false}
-%  \SI{40}{\second}
-%\end{LaTeXexample}
-%
-%\DescribeOption{colourneg}
-%\DescribeOption{negcolour}
-%\SpecialOptionIndex{colorneg}
-%\SpecialOptionIndex{negcolor}
-% \currpkg can automatically add a colour to negative numbers.  This
-% is turned on using the \opt{colourneg} switch.  The colour used is
-% set by the \opt{negcolour} option; both options are available using
-% US spellings.
-%
-%\subsection{International support}
-%\DescribeOption{locale}
-% \currpkg allows the user to switch between the typographic
-% conventions of different (geographical) areas by using
-% \latin{locales}.  Currently, the package is supplied with
-% configurations for locales \opt{UK}, \opt{USA}, \opt{DE} (Germany)
-% and \opt{ZA} (South Africa). The \opt{locale} option is used to
-% switch to a particular locale.
-%\begin{LaTeXexample}
-%  \SI{1.234}{\metre}\\
-%  \SI[locale=DE]{6.789}{\metre}
-%\end{LaTeXexample}
-%
-%\DescribeOption{loctolang}
-% Locales are distinct from \pkg{babel} languages, as typographic
-% conventions are not tightly integrated with language.  However, it
-% is useful to be able to associate a particular locale with a
-% \pkg{babel} language.  The option \opt{loctolang} handles this, and
-% expects pairs of values:
-% \opt{loctolang=\meta{locale}:\meta{language}}.
-%\begin{LaTeXexample}
-%  \sisetup{loctolang={UK:UKenglish,DE:german}}\\
-%  \SI{6.022e23}{\per\mole}\\
-%  \selectlanguage{german}\\
-%  \SI{6.022e23}{\per\mole}
-%\end{LaTeXexample}
-%
-%\subsection{Package control}
-%\DescribeOption{load}
-%\DescribeOption{noload}
-%\DescribeOption{alsoload}
-% The package keeps most of the unit and abbreviations definitions in
-% files separate from \file{siunitx.sty}.  To control what is loaded,
-% three complementary options are provided, all of which take a list
-% of one or more choices.  \opt{load} and \opt{alsoload} define which
-% support configuration files are loaded.  The list in \opt{load}
-% recognises the value \opt{default}, which is expanded to the normal
-% list before loading. The difference between \opt{load} and
-% \opt{alsoload} is that \opt{load} specifies the \emph{complete}
-% list of files to load, whereas \opt{alsoload} adds to the existing
-% list. To use the \opt{load} option successfully requires knowing
-% everything that is needed. The \opt{noload} option can be used to
-% delete one or more items from the \opt{load} list, without needing
-% to know what is on it.\footnote{\opt{noload} does not prevent the
-% loading of a file needed by one which is loaded.  Thus the package
-% may internally override a \opt{noload} value if needed.}
-%
-%\DescribeOption{log}
-%\DescribeOption{debug}
-% To control data written to the \ext{log} file, the \opt{log} option
-% is provided.  This takes a value from the list \defaultopt{normal},
-% \opt{none}, \opt{minimal}, \opt{errors} and \opt{debug}.  As would
-% be expected, these indicate the amount of detail written to the log
-% file. As a shortcut to \opt{log=debug}, the package also recognises
-% the \opt{debug} option directly.
-%
-%\DescribeOption{strict}
-% Some users will want to stick closely to the official rules for
-% typesetting units.  This could be made complicated if the options
-% for non-standards behaviour could not be turned off.  The load-time
-% option \opt{strict} resets package behaviour to follow the rules
-% closely, and disables options which deviate from this.  If the
-% package is loaded with the \opt{strict} option, all output is made
-% in maths mode using the upright serif font.
-%
-%\subsection{Back-compatibility options}
-%\DescribeOption{emulate}
-% The package can emulate \SIunits, \SIstyle, \unitsdef, \units,
-% \pkg{hepunits}, \pkg{fancyunits} and \pkg{fancynum}.  Giving the
-% \opt{emulate=\meta{package}} option will give the desired
-% emulation, and combinations which would be possible with the real
-% packages will also work here. The package will recognise the
-% options of the emulated packages.  This will automatically cause
-% emulation to be switched on.
-%
-%\subsection{Summary of all options}
-% \ref{tab:allopt} lists a summary of the package options (excluding
-% those for backward-compatibility).  A reminder or the input format
-% is also provided.
-%\begin{longtable}{>{\ttfamily}lll}
-%    \caption{All package options\label{tab:allopt}}\\
+%\end{LaTeXdemo}
+% The table-printing code will omit any part of a number which has no
+% space reserved, placing a warning in the LaTeX log. This means that
+% uncertainties and exponents will not be printed if no space is reserved 
+% for them.
+%
+%\DescribeOption{table-format}
+% As a short cut for the preceding options, \pkg{siunitx} also 
+% provides the \opt{table-format} option. This can be used to give the
+% same information about the space to reserve for a number in a 
+% \enquote{compressed} manner. The input to \opt{table-format} should
+% consist of a number showing how many figures to reserve in each part
+% of the input. Thus
+%\begin{LaTeXdemo}[code only]
+%  \sisetup{
+%    table-format = 3.2
+%  }  
+%\end{LaTeXdemo} 
+% is equivalent to 
+%\begin{LaTeXdemo}[code only]
+%  \sisetup{
+%    table-figures-integer = 3,
+%    table-figures-decimal = 2
+%  }  
+%\end{LaTeXdemo} 
+% The \opt{table-format} option will also correctly interpret the 
+% presence of a sign, so that
+%\begin{LaTeXdemo}[code only]
+%  \sisetup{
+%    table-format = +3.2e+4
+%  }  
+%\end{LaTeXdemo} 
+% will have the same effect as
+%\begin{LaTeXdemo}[code only]
+%  \sisetup{
+%    table-figures-integer  = 3,
+%    table-figures-decimal  = 2,
+%    table-figures-exponent = 4,
+%    table-sign-mantissa,
+%    table-sign-exponent
+%  }  
+%\end{LaTeXdemo} 
+% It is important to note that any parts of a number \emph{not} 
+% specified in the table format argument are set to be absent (the
+% number of figures is set to zero). Setting the \opt{table-format}
+% option also resets \opt{table-number-alignment} to \opt{center}
+% (\cref{tab:S:format}).
+%\begin{LaTeXdemo}[code and float]
+%  \begin{table}
+%    \caption{Using the \opt{table-format} option.}
+%    \label{tab:S:format}
+%    \centering
+%    \begin{tabular}{
+%      S
+%      S[table-format =  2.2]
+%      S[table-format =  2.2(1)]
+%      S[table-format = +2.2]
+%      S[table-format =  2.2e1]
+%      }
 %    \toprule
-%    Option & Type & Description \\
+%        {Values}
+%      & {Values}
+%      & {Values}
+%      & {Values}
+%      & {Values} \\
 %    \midrule
-%  \endfirsthead
+%       2.3  &  2.3  &  2.3(5)  &   2.3  &  2.3e8  \\
+%      34.23 & 34.23 & 34.23(4) &  34.23 & 34.23   \\
+%      56.78 & 56.78 & 56.78(3) & -56.78 & 56.78e3 \\
+%       3,76 &  3,76 &  3.76(2) & +-3.76 &      e6 \\
+%    \bottomrule
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{table-space-text-pre}
+%\DescribeOption{table-space-text-post}
+% Space for material before and after the \texttt{S} column can
+% be reserved by giving model text for the options
+% \opt{table-space-text-pre} and \opt{\ldots -post}.
+% This is then used to provide the necessary gap while maintaining 
+% alignment (\cref{tab:S:ends}).
+%\begin{LaTeXdemo}[code and float]
+%  \begin{table}
+%    \caption{Text before and after numbers.}
+%    \label{tab:S:ends}
+%    \centering
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 2,
+%      table-figures-decimal  = 4,
+%      table-space-text-pre   = $ > $,
+%      table-space-text-post  = 
+%        \textsuperscript{\emph{a}}
+%    }
+%    \begin{tabular}{S}
 %    \toprule
-%    Option & Type & Description \\
+%    {Values} \\
 %    \midrule
-%  \endhead
+%             2.3456  \\
+%            34.2345  \textsuperscript{\emph{a}}\\
+%            56.7835  \\
+%      $ > $ 90.473   \\
 %    \bottomrule
-%    \multicolumn{3}{r}{\emph{Continued on next page}}
-%  \endfoot
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{table-align-text-post}
+% Note markers are often given in tables after the numerical content. It
+% may be desirable for these to close up to the numbers. Whether this 
+% takes place is controlled by the \opt{table-align-text-post} 
+% option (\cref{tab:S:notes}).\footnote{Currently, closing up material 
+% to numbers is only supported for simple real numbers. A more 
+% extended method, including a second option for text before numbers, 
+% is planned for \pkg{siunitx} v2.1.}
+%\begin{LaTeXdemo}[code and float]
+%  \begin{table}
+%    \caption{Closing notes up to text.}
+%    \label{tab:S:notes}
+%    \newcommand\NoteMark[1]{%
+%      \textsuperscript{\emph{#1}}%
+%    }
+%    \centering
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 2,
+%      table-figures-decimal  = 4,
+%    }
+%    \begin{tabular}{
+%      S
+%      S[table-align-text-post = false]
+%    }
+%    \toprule
+%      {Values}             & {Values} \\
+%    \midrule
+%       2.3456              & 2.3456 \\
+%      34.234  \NoteMark{a} & 34.234 \NoteMark{a} \\
+%      56.78   \NoteMark{b} & 56.78  \NoteMark{b} \\
+%      90.4    \NoteMark{c} & 90.4   \NoteMark{c} \\
 %    \bottomrule
-%  \endlastfoot
-%  addsign & List & Add sign to number \\
-%  allowlitunits & Boolean & Allow literal input of units \\
-%  allowoptarg & Boolean & Allow optional argument to unit macros \\
-%  allowzeroexp & Boolean & Allow \num[allowzeroexp]{e0} \\
-%  angformat & List & Conversion of angle format \\
-%  anglesep & List or literal & Space between angle components \\
-%  astroang & Boolean & Astronomy-style angles \\
-%  closeerr & Literal & Closes potential-ambiguous error \\
-%  closefrac & Literal & Closes potential-ambiguous fraction \\
-%  closerange & Literal & Closes potential-ambiguous range \\
-%  color & Literal & Colour used for units and values \\
-%  colour & Literal & Colour used for units and values \\
-%  colorall & Boolean & Switch for colouring all output \\
-%  colourall & Boolean & Switch for colouring all output \\
-%  colorneg & Boolean & Colour negative numbers \\
-%  colourneg & Boolean & Colour negative numbers \\
-%  colorunits & Boolean & Switch for colouring units \\
-%  colourunits & Boolean & Switch for colouring units \\
-%  colorvalues & Boolean & Switch for colouring values \\
-%  colourvalues & Boolean & Switch for colouring values \\
-%  decimalsymbol & List or literal & Decimal symbol \\
-%  debug & Boolean & Write debugging data to log \\
-%  detectdisplay & Boolean & Treat display maths separately \\
-%  digitsep & List & Separation of digits in large numbers \\
-%  dp & Integer & Number of decimal places to \\
-%   & & output numbers to \\
-%  emulate & Modules & Emulation modules to load \\
-%  errspace & List & Spacing of bracketed error \\
-%  eVcorra & Length & Spacing correction in \eV \\
-%  eVcorrb & Length & Spacing correction after \eV \\
-%  expbase & List or literal & Base used for exponents \\
-%  expproduct & List or literal & Product sign for exponents \\
-%  fixdp & Boolean & Switch for fixing decimal \\
-%   & & places of numbers \\
-%  fixsf & Boolean & Switch for fixing significant \\
-%    & & figures of numbers \\
-%  fraction & List & Method used when setting \opt{per=frac} \\
-%  inlinebold & List & Select how inline bold is tested \\
-%  load & Modules & Modules to load \\
-%  locale & Modules & Locale to follow \\
-%  loctolang & Special & Associate locale with \pkg{babel}
-%    language \\
-%  log & List & Amount of data added to log \\
-%  mathOmega & Literal & ``$\makeatletter\si@mathsOmega\makeatother$''
-%    symbol in maths mode \\
-%  mathcelsius & Literal & ``$\makeatletter\si@mathscelsius\makeatother$''
-%    symbol in maths mode \\
-%  mathdegree & Literal & ``$\makeatletter\si@mathsdegree\makeatother$''
-%    symbol in maths mode \\
-%  mathminute & Literal & ``$\makeatletter\si@mathsminute\makeatother$''
-%    symbol in maths mode \\
-%  mathmu & Literal & ``$\makeatletter\si@mathsmu\makeatother$''
-%    symbol in maths mode \\
-%  mathringA & Literal & ``$\makeatletter\si@mathsringA\makeatother$''
-%    symbol in maths mode \\
-%  mathrm & Csname & Roman maths font \\
-%  mathsOmega & Literal & ``$\makeatletter\si@mathsOmega\makeatother$''
-%    symbol in maths mode \\
-%  mathscelsius & Literal & ``$\makeatletter\si@mathscelsius\makeatother$''
-%    symbol in maths mode \\
-%  mathsdegree & Literal & ``$\makeatletter\si@mathsdegree\makeatother$''
-%    symbol in maths mode \\
-%  mathsecond & Literal & ``$\makeatletter\si@mathssecond\makeatother$''
-%    symbol in maths mode \\
-%  mathsf & Csname & Sans serif maths font \\
-%  mathsminute & Literal & ``$\makeatletter\si@mathsminute\makeatother$''
-%    symbol in maths mode \\
-%  mathsmu & Literal & ``$\makeatletter\si@mathsmu\makeatother$''
-%    symbol in maths mode \\
-%  mathsringA & Literal & ``$\makeatletter\si@mathsringA\makeatother$''
-%    symbol in maths mode \\
-%  mathsrm & Csname & Roman maths font \\
-%  mathssecond & Literal & ``$\makeatletter\si@mathssecond\makeatother$''
-%    symbol in maths mode \\
-%  mathssf & Csname & Sans serif maths font \\
-%  mathstt & Csname & Fixed-width maths font \\
-%  mathtt & Csname & Fixed-width maths font \\
-%  mode & List & Use text or maths mode for \\
-%   & & typesetting \\
-%  negcolor & Literal & Colour used for negative numbers \\
-%  negcolour & Literal & Colour used for negative numbers \\
-%  noload & Modules & Modules not to load \\
-%  numaddn & Literal & Additional input allowed in numbers \\
-%  numcloseerr & Literal & Character indicating end of \\
-%   & & numerical error\\
-%  numdecimal & Literal & Decimal symbols in numbers \\
-%  numdigits & Literal & Digit characters in numbers \\
-%  numdiv & Literal & Division characters in numbers \\
-%  numexp & Literal & Exponent characters in numbers \\
-%  numgobble & Literal & Characters to ignore in numbers \\
-%  numopenerr & Literal & Character indicating start of \\
-%   & & numerical error\\
-%  numprod & Literal & Characters used for a product \\
-%  numsign & Literal & Sign characters in numbers \\
-%  obeyall & Boolean & Combination of \opt{obeybold}, \\
-%   & & \opt{obeyitalic} and \opt{obeymode} \\
-%  obeybold & Boolean & Check local bold setting \\
-%  obeyitalic & Boolean & Check local italic setting \\
-%  obeymode & Boolean & Check local mode (text/maths) \\
-%  openerr & Literal & Opens potentially-ambiguous error \\
-%  openfrac & Literal & Opens potentially-ambiguous fraction \\
-%  openrange & Literal & Opens potentially-ambiguous range \\
-%  padangle & List & Add zeros to blank parts of angles \\
-%  padnumber & List & Add zeros to blank parts of numbers \\
-%  per & List & Behaviour of \cs{per} \\
-%  prefixbase & List or literal & Base used when making prefixes \\
-%   & & numerical \\
-%  prefixproduct & List or literal & Product sign for prefixes \\
-%  prefixsymbolic & Boolean & Behaviour of unit prefixes\\
-%  prespace & Boolean & Add space before units \\
-%  redefsymbols & Boolean & Use better symbols if available \\
-%  repeatunits & List & Repeat units with separated errors, \\
-%   & &  products and in ranges \\
-%  retainplus & Boolean & Retain explicit plus sign\\
-%  seperr & Boolean & Separate number and error \\
-%  sepfour & Boolean & Separate four-digit numbers \\
-%  sf & Integer & Number of significant figures \\
-%   & & to output numbers to \\
-%  sign & List or literal & Sign to add to numbers \\
-%  slash & List or literal & Symbol used for ``/'' \\
-%  stickyper & Boolean & Require \cs{per} only once \\
-%  strict & Boolean & Obey the rules strictly \\
-%  strictarc & Boolean & Require exactly zero or \\
-%   & & two semi-colons \\
-%  tabalign & List & Positioning of all column data \\
-%  tabalignexp & Boolean & Alignment of exponents in tables \\
-%  tabautofit & Boolean & Switch for rounding numbers to \\
-%   & & length given by \opt{tabformat} \\
-%  tabformat & Number & Space reserved in table for numbers \\
-%  tabnumalign & List & Alignment of |S| column numbers \\
-%  tabparseonly & Boolean & Do not align |S| columns \\
-%   & & on decimal marker \\
-%  tabtextalign & List & Positioning of text in |S| columns \\
-%  tabunitalign & List & Positioning of units in |s| columns \\
-%  textcelsius & Literal & ``$^{\circ}$C'' symbol in text mode \\
-%  textdegree & Literal & ``${\circ}$'' symbol in text mode \\
-%  textminute & Literal & ``$'$'' symbol in text mode \\
-%  textmu & Literal & ``$\upmu$'' symbol in text mode \\
-%  textomega & Literal & ``$\Omega$'' symbol in text mode \\
-%  textringa & Literal & ``\AA'' symbol in maths mode \\
-%  textrm & Csname & Roman text font \\
-%  textsecond & Literal & ``$''$'' symbol in text mode \\
-%  textsf & Csname & Sans serif text font \\
-%  texttt & Csname & Fixed-width text font \\
-%  tightpm & Boolean & Reduce space around $\pm$ \\
-%  tophrase & List or literal & The phrase ``to'' for ranges \\
-%  trapambigerr & Boolean & Check for ambiguous errors \\
-%  trapambigfrac & Boolean & Check for ambiguous fractions \\
-%  trapambigrange & Boolean & Check for ambiguous ranges \\
-%  unitcolor & Literal & Switch for colouring units \\
-%  unitcolour & Literal & Switch for colouring units \\
-%  unitmathrm & Csname & Roman maths font for units \\
-%  unitmathsf & Csname & Sans serif maths font for units \\
-%  unitmathsrm & Csname & Roman maths font for units \\
-%  unitmathssf & Csname & Sans serif maths font for units \\
-%  unitmathstt & Csname & Fixed-width maths font for units \\
-%  unitmathtt & Csname & Fixed-width maths font for units \\
-%  unitmode & List &  As \opt{mode}, for units only \\
-%  unitsep & List or literal & Separator for units \\
-%  unitspace & List or literal & Space used for ``|~|'' in units \\
-%  valuecolor & Literal & Switch for colouring value \\
-%  valuecolour & Literal & Switch for colouring value \\
-%  valuemathrm & Csname & Roman maths font for values \\
-%  valuemathsf & Csname & Sans serif maths font for values \\
-%  valuemathsrm & Csname & Roman maths font for values \\
-%  valuemathssf & Csname & Sans serif maths font for values \\
-%  valuemathstt & Csname & Fixed-width maths font for values \\
-%  valuemathtt & Csname & Fixed-width maths font for values \\
-%  valuemode & List &  As \opt{mode}, for values only \\
-%  valuesep & List or literal & Separator between value and unit \\
-%  xspace & Boolean & Use \pkg{xspace} after units \\
-%\end{longtable}
-%
-%\section{Emulation of other packages}
-% \currpkg has been designed as a replacement for \SIunits, \SIstyle,
-% \unitsdef, \units, \pkg{hepunits}, \pkg{fancyunits} and
-% \pkg{fancynum}. It therefore provides options reproduce the
-% functions of all of these packages.  In this way, \currpkg should
-% be usable as a straight replacement for the older
-% packages.\footnote{User macros means that they are described in the
-% package documentation; simply not containing an \texttt{@} does not
-% mean they will have been emulated.}  This means for example that
-% the \cs{num} macro takes an optional star when emulating \SIstyle.
-% However, there are some points that should be remembered.  In
-% particular, \currpkg validates numerical input, meaning that places
-% where a number is expected in the older packages \emph{require} a
-% number when emulated by \currpkg.
-%
-% The \numprint package has provided many useful ideas for the code
-% used here for number formatting. The basic use of the \cs{numprint}
-% (or \cs{np}) macro can be reproduced using \currpkg.  However,
-% \numprint is large and complex, with its own backward-compatibility
-% options.  As a result, emulation of \numprint is not provided here.
-% To use a \numprint document with \currpkg, the \cs{numprint} macro
-% could be provided using the following code.
-%^^A Need to deal with \cs{numprint} being defined.
-%\let\numprint\relax
-%\begin{LaTeXexample}
-%  \newcommand*{\numprint}[2][]{\SI[obeymode]{#2}{#1}}\\
-%  \numprint{-123456} \\
-%  \numprint[N/mm^2]{-123456}
-%\end{LaTeXexample}
-%^^A Back to the normal - with \cs{newcommand}
-%\newcommand*{\numprint}{\pkg{numprint}\xspace}
-%
-% \currpkg can be used more-or-less directly to replace both
-% \pkg{dcolumn} and \pkg{rccol}.  As is explained in the code
-% section, much of the column-alignment system here is taken from
-% \pkg{dcolumn}, while \pkg{rccol} provided a model for a
-% customisable system.  However, neither package has been directly
-% emulated here.  The |S| column type can be used to replace both |D|
-% and |R| columns by setting the appropriate package options.
-%
-%\section{Configuration files}
-% \currpkg is a modular package.  The unit definitions, abbreviations
-% and locales are all stored in configuration files.  These all take
-% names of the form \file{si-\meta{name}.cfg}, where \meta{name} is
-% the part of the filename used as an option in \cs{sisetup} or when
-% loading \currpkg.  Producing new configuration files therefore
-% consists of making a suitably-named file and adding it to the path
-% searched by \TeX.  The files should normally consist of settings
-% (in \cs{sisetup}) and unit definitions, \etc.
-%
-%\DescribeMacro{\addtolocale}
-% To allow arbitrary macros to be stored in locales, the
-% \cs{addtolocale} macro is provided.  This ensures that arbitrary
-% text is only executed when using a locale, not when loading it. The
-% macro takes two arguments, \marg{locale} and \marg{code}.
-%\begin{LaTeXexample}
-%  \addtolocale{DE}{TEST}
-%  Some text as filler \\
-%  \sisetup{locale=DE}
-%  This example is rather trivial!
-%\end{LaTeXexample}
-%
-%\DescribeMacro{\requiresiconfigs}
-% To load one or more configuration files from inside another
-% configuration file, the \cs{requiresiconfigs} macro is provided.
-% This accepts a comma-separated list of configuration names, in the
-% same way as \opt{load} or \opt{noload}.
-%
-% In addition to the various configuration files provided with the
-% package, a local file \file{siunitx.cfg} may be provided.  This is
-% read at the end of loading \currpkg, and allows the user to include
-% any local definitions or settings easily.
-%
-%\section{Common questions}
-%\subsection{Why do I need \cs{per} more than once?}
-% The unit engine of \currpkg is based around the English method for
-% reading units out loud. Thus \si{\joule\per\mole\per\kelvin} is
-% pronounced ``joules per mole per kelvin''.  Hence by default you
-% need to put \cs{per} before each item in the denominator of a unit.
-% The behaviour can be altered by setting the \opt{stickyper} option.
-%
-%\subsection{Why is the order of my units changed?}
-% Then using \opt{per=reciprocal}, the units are typeset as given.
-% However, when using \opt{per=slash} or \opt{per=fraction}, the
-% package needs to find which ones are in the denominator.  It then
-% prints the numerator and denominator separately.  So if you give a
-% unit in the denominator \emph{before} one in the numerator, they
-% have to be re-ordered.\footnote{``Double division''
-% (\SI{1}{s/m/kg}) is mathematically incorrect.}
-%\begin{LaTeXexample}
-%  \SI{88}{\per\kilogram\metre} \\
-%  \SI[per=slash]{66}{\per\kilogram\metre}
-%\end{LaTeXexample}
-%
-%\subsection{Why are compound units not recommended outside of
-%  \cs{SI}/\cs{si}?}
-% To fully process units made up of several parts, the processor has
-% to know where the end of the unit is.  When the unit macros are
-% used outside of \cs{SI}/\cs{si}, this is not the case.  The package
-% therefore does its best, but results may be sub-optimal.  To get
-% consistent results, either define a new \emph{single} unit, or keep
-% compound units inside \cs{SI} and \cs{si}.
-%\begin{LaTeXexample}
-%  \metre\per\micro\second \\
-%  \si{\metre\per\micro\second} \\
-%  \newunit{\myunit}{\metre\per\micro\second}
-%  \myunit
-%  \newunit{\myunittwo}{\kilogram\myunit} \\
-%  \myunittwo \\
-%  \kilogram\myunit
-%\end{LaTeXexample}
-% Notice the difference in behaviour of \cs{per} in the first two
-% lines, and the spacing error on the last line in the example.
-%
-%\subsection{How do I set superscripts to use lining numbers?}
-% Lowercase (``old style'') numbers are favoured by many people for
-% use in running text.  However, this does not necessarily look good
-% in superscripts. The mode used to typeset data can be varied, so
-% that maths mode numbers are used for the unit part of the output.
-%\begin{LaTeXexample}
-%  \SI[mode=text]{1234}{\metre\per\second}\\
-%  \SI[valuemode=text,unitmode=maths]{1234}{\metre\per\second}
-%\end{LaTeXexample}
-%
-%\subsection{Why do most of the examples use
-%  \texorpdfstring{\si{\joule\per\mole\per\kelvin}}{J mol-1 K-1}?}
-% The package author is a chemist, and this is the unit of entropy
-% (disorder).  It nicely demonstrates the use of the \cs{per} macro,
-% and so it crops up a lot.  It is also in the subsection heading
-% here to act as a test with \pkg{hyperref} and moving arguments!
-%
-%\subsection{What can \numprint do that \currpkg cannot?}
-% \currpkg uses a lot of ideas from \numprint: a reasonable amount of
-% the number-processing code here is based on that in \numprint.
-% However, the two packages have somewhat different aims, and as a
-% result there are things that \numprint can do that \currpkg does
-% not implement.  The main features of \numprint not available here
-% are:
-%\begin{itemize}
-%  \item General support for numbers with base other than $10$ (see
-%    \pkg{nbaseprt});
-%  \item Alignment of the decimal marker of powers in tables;
-%  \item Alignment of numbers in running text;
-%  \item Specific formatting commands for \TeX\ counters and lengths.
-%\end{itemize}
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
 %
-%\section{Tricks and known issues}
-%
-%\subsection{Ensuring maths mode}
-% Due to the possibility of output in either maths or text mode, any
-% input which requires a particular mode needs to be protected.  You
-% cannot use |$|\ldots|$|, as this can get ``caught out'', but also
-% as it may give hard-to-follow errors.  Always use \cs{ensuremath}
-% to force maths processing, and \cs{text} (from the \AMS\TeX\
-% bundle) to ensure text mode.
-%
-%\subsection{Using \texttt{.} and fixed spaces in units}
-% To use a literal |.| in a unit, it has to be within an extra set of
-% braces.  This does not need any extra protection, unlike the
-% situation with \SIstyle (for example, no \cs{text} macro is
-% needed).  The fixed space (|~|) is more problematic: set
-% \opt{unitspace=space} to get a full space here.
-%\begin{LaTeXexample}
-%  \newunit[unitspace=space]{\myunit}{V~vs{.}~NHE}%
-%  \SI{10}{\myunit}
-%\end{LaTeXexample}
-%
-%\subsection{Passing unprocessed digits through an \texttt{S}
-%  column}
-% The method used to detect numbers in an |S| column will pick up
-% material wrapped inside braces if there is more than a single
-% character inside the braces.  If you want to pass a \emph{single}
-% numerical character without processing it, you need two sets of
-% braces (\ref{tab:S-limits}).
-%\begin{LaTeXexample}[float]
+%\DescribeOption{table-auto-round}
+% The contents of table cells can automatically be rounded or
+% zero-filled to the number of decimal digits given for the 
+% \opt{table-figures-decimal} option. This mode is activated using
+% the \opt{table-auto-round} switch, as illustrated in 
+% \cref{tab:S:auto}.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
 %    \centering
-%    \caption{Passing single digit characters}
-%    \label{tab:S-limits}
-%    \begin{tabular}{S[colourall,colour=orange]}
+%    \caption{The \opt{table-auto-round} option.}
+%    \label{tab:S:auto}
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 1,
+%      table-figures-decimal  = 3
+%    }
+%    % Notice the overfull hbox which results with
+%    % the first column
+%    \begin{tabular}{
+%      S
+%      S[table-auto-round]
+%    }
 %      \toprule
-%        {Heading} \\
+%        {Header} & {Header} \\
 %      \midrule
-%        {1-2} \\
-%        {1}   \\
-%        {{1}} \\
-%        {{-}} \\ % Using {-} gives an error!
+%        1.2    & 1.2    \\
+%        1.2345 & 1.2345 \\
 %      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\subsection{Limitations of \cs{mathrm}}
-% The package uses the \cs{mathrm} font family by default to typeset
-% output in maths mode.  This however has a few side-effects.  For
-% example, the Greek alphabet can give odd results.\footnote{This
-% depends on your font setup; this document uses T1 encoding, which
-% shows the issue, whereas using OT1 does not.}  The use of the
-% \cs{mathnormal} font \emph{may} get around this issue.
-%\begin{LaTeXexample}
-%  \num[numaddn=\pi]{4\pi e-7}\\
-%  \num[numaddn=\pi,mathsrm=mathnormal]{4\pi e-7}
-%\end{LaTeXexample}
-% On the other hand, you may want to use text mode, in which case
-% \cs{ensuremath} is needed.  Depending on the exact circumstances,
-% the \LaTeX\ protection mechanism (\cs{DeclareRobustCommand}) may be
-% sufficient; in some cases, this will fail and the \eTeX\
-% \cs{protected} system may be required. There are several potential
-% pitfalls in this area; experimentation may well be needed.
-%\begin{LaTeXexample}
-%  \DeclareRobustCommand*{\numpi}{\ensuremath{\pi}}
-%  \num[numaddn=\numpi,mode=text]{4\numpi e-7}
-%\end{LaTeXexample}
-%
-%\subsection{Effects of emulation}
-% The package has been designed so that almost everything can be set
-% using the options.  In the emulation code, some internal macros are
-% redefined.  This is because the legacy packages do odd things,
-% which are deliberately not implemented by \currpkg.  Using an
-% emulation file will prevent subsequent loading of the real package.
-% This is to prevent errors or, worse, difficult to diagnose changes
-% to output.
-%
-%\subsection{Centring columns on non-decimal input}
-% The \pkg{dcolumn} manual suggests using that package to align a
-% column on a $\pm$ sign. The same type of output is possible using
-% \currpkg, but some care is needed (\ref{tab:dcolumn}).  Odd things
-% may happen: use with care!
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+%
+%\DescribeOption{parse-numbers}
+% When the \opt{parse-numbers} option is set to \opt{false}, then
+% the alignment code for tables takes a different approach. The
+% output is always set in math mode, and alignment takes place
+% at the first decimal marker. This is achieved by making it 
+% active in math mode. When reserving space for content only
+% the integer and decimal values for the mantissa are considered
+% (\cref{tab:S:nonparsed}).
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
+%    \caption{Aligning without parsing.}
+%    \label{tab:S:nonparsed}
+%    \sisetup{
+%      parse-numbers = false,
+%      table-figures-integer = 2,
+%      table-figures-decimal = 3
+%    }
 %    \centering
-%    \caption{Non-standard \texttt{S} column}
-%    \label{tab:dcolumn}
-%    \begin{tabular}{%
-%      S[digitsep=none,decimalsymbol={\,\pm\,},
-%        numdigits={0123456789.},numdecimal=+]}
+%    \begin{tabular}{
+%      S
+%      S[table-number-alignment = center]
+%      S[table-number-alignment = right]
+%      S[table-number-alignment = left]
+%      }
 %    \toprule
-%    {Some Values} \\
+%        \multicolumn{1}{c}{Some values}
+%      & \multicolumn{1}{c}{Some values}
+%      & \multicolumn{1}{c}{Some values}
+%      & \multicolumn{1}{c}{Some values} \\
 %    \midrule
-%    2.3456  + 0.02  \\
-%    34.2345 + 0.001 \\
-%    56.7835 + 0.067 \\
-%    90.473  + 0.021 \\
+%       2.35  &    2.35  &    2.35  &   2.35   \\
+%      34.234 &   34.234 &   34.234 &  34.234  \\
+%      56.783 &   56.783 &   56.783 &  56.783  \\
+%       3,762 &    3,762 &    3,762 &   3.762  \\
+%    \sqrt{2} & \sqrt{2} & \sqrt{2} & \sqrt{2} \\
 %    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{table-text-alignment}
+% Cell contents which are not part of a number can be protected
+% using braces, as illustrated. Cells which contain no numerical data
+% at all are aligned using the setting specified by the 
+% \opt{table-text-alignment} option, which recognises the values
+% \opt{center}, \opt{left} and \opt{right} (\cref{tab:S:text}).
+%\begin{LaTeXdemo}[code and float]
+%  \begin{table}
+%    \caption{Aligning text in \texttt{S} columns.}
+%    \label{tab:S:text}
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 4,
+%      table-figures-decimal  = 4
+%    }
+%    \centering
+%    \begin{tabular}{
+%      S
+%      S[table-text-alignment = left]
+%      S[table-text-alignment = right]
+%      }
+%    \toprule
+%        {Values}
+%      & {Values}
+%      & {Values} \\
+%    \midrule
+%      992.435  &  992.435  &  992.435  \\
+%     7734.2344 & 7734.2344 & 7734.2344 \\
+%       56.7834 &   56.7834 &   56.7834 \\
+%        3,7462 &    3,7462 &    3,7462 \\
+%    \bottomrule
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
+% 
+%\DescribeOption{table-unit-alignment}
+% The contents of \texttt{s} columns can be centred or aligned to the
+% left or right using the \opt{table-unit-alignment} option. As for the
+% other alignment options, this recognises the choices \opt{center},
+% \opt{left} and \opt{right}. 
+%\begin{LaTeXdemo}[code and float]
+%  \begin{table}
+%    \centering
+%    \caption{Alignment options in \texttt{s} columns.}
+%    \label{tab:s:align}
+%    \begin{tabular}
+%      {
+%        s[table-unit-alignment = right]
+%        s
+%        s[table-unit-alignment = left]
+%      }      
+%      \toprule
+%        {Left-aligned}  &   
+%        {Centred text}  &
+%        {Right-aligned} \\
+%      \midrule
+%        \metre\per\second & \metre\per\second & \metre\per\second \\
+%        \kilogram         & \kilogram         & \kilogram         \\
+%      \bottomrule
+%    \end{tabular}
+%  \end{table}
+%\end{LaTeXdemo}
+%
+%\DescribeOption{table-alignment}
+% The three table alignment options (\opt{table-number-alignment}, 
+% \opt{table-text-alignment} and \opt{table-unit-alignment}) can be set 
+% to the same value using the \opt{table-alignment} option. This will 
+% set all three alignment options to the same value (one of \opt{center}, 
+% \opt{right} or \opt{left}).
+% 
+%\subsection{Symbols}
 %
+% Most units use letters as the symbol for the unit, and these are all
+% very easy to control.  However, a small number of units use other
+% symbols, and matching these to the body text requires more work.
+% \pkg{siunitx} provides appropriate symbols for commonly-used units,
+% but the definitions may need adjustment depending on the body font
+% used in a document.
+% 
+%\DescribeOption{redefine-symbols}
+% The package provides one general option for the handling of symbols.
+% If the packages \pkg{textcomp} or \pkg{upgreek} are loaded, symbols 
+% can be taken from these for units, rather than using the
+% \pkg{siunitx} default values. The switch \opt{redefine-symbols} 
+% can be used to turn this behaviour on or off: the standard setting
+% is \opt{true}.
+% 
+% The individual symbols are set up independently for math and text
+% output, and are summarised in \cref{tab:opt:symbols}.  Many of 
+% the definitions are variations using \cs{text} or \cs{ensuremath} to
+% produce the correct output, as the symbols available in the document
+% may vary considerably. In the case of the micro symbol 
+% (\SIUnitSymbolMicro), \pkg{sunitx} provides a suitable low-level 
+% definition for the symbol. Depending on the fonts available, this
+% may need to be replaced by an alternative by the user. The 
+% ohm symbol (\SIUnitSymbolOhm) is usually set to \cs{Omega}, but
+% will check that this has not been redefined as a slanted letter. If
+% \cs{Omega} has been redefined, an alternative definition is used.
+% 
+%\begin{table}
+%  \centering
+%  \caption{Symbol options.}
+%  \label{tab:opt:symbols}
+%  \begin{tabular}{>{\ttfamily}ll>{\ttfamily}l}
+%    \toprule
+%      \multicolumn{1}{l}{Option name} & 
+%      Type &
+%      \multicolumn{1}{l}{Default} \\
+%    \midrule ^^A (
+%      math-angstrom    & Literal & \verb=\text{\AA}=                 \\ 
+%      math-arcminute   & Literal & \verb={}^{\prime}=                \\
+%      math-arcsecond   & Literal & \verb={}^{\prime\prime}=          \\
+%      math-celsius     & Literal & \verb={}^{\circ}=                 \\
+%        & & \verb=\kern -\scriptspace \mathrm{C}= \\ 
+%      math-degree      & Literal & \verb={}^{\circ}=                 \\
+%      math-micro       & Literal & \meta{see text}                   \\
+%      math-ohm         & Literal & \cs{Omega}                        \\
+%      redefine-symbols & Switch & true \\
+%      text-angstrom    & Literal & \cs{AA}                           \\ 
+%      text-arcminute   & Literal & \verb=\ensuremath{{}^{\prime}}=   \\
+%      text-arcsecond   & Literal & 
+%        \verb=\ensuremath{{}^{\prime\prime}}= \\ 
+%      text-celsius     & Literal &  \verb=\ensuremath{{}^{\circ}=    \\
+%        & & \verb=\kern -\scriptspace \text{C}}= \\ 
+%      text-degree      & Literal & \verb=\ensuremath{{}^{\circ}}=    \\ 
+%      text-micro       & Literal & \meta{see text}                   \\
+%      text-ohm         & Literal & \verb=\ensuremath{\Omega}=        \\
+%    \bottomrule
+%  \end{tabular}
+%\end{table}
+%
+%\DescribeMacro{\SIUnitSymbolAngstrom}
+%\DescribeMacro{\SIUnitSymbolArcminute}
+%\DescribeMacro{\SIUnitSymbolArcsecond}
+%\DescribeMacro{\SIUnitSymbolCelsius}
+%\DescribeMacro{\SIUnitSymbolDegree}
+%\DescribeMacro{\SIUnitSymbolMicro}
+%\DescribeMacro{\SIUnitSymbolOhm}
+% The math and text symbols defined above are wrapped up into mode
+% independent functions with user names.  These are then used in the
+% definitions of the appropriate units.  For example, the micro
+% symbol can be accessed using the macro \cs{SIUnitSymbolMicro}.
+% Notice that these names capitalise the unit name (to make reading 
+% the macro name easier!).\footnote{The function 
+% \cs{SIUnitSymbolAngstrom} uses the name without accents.}
+% 
+%\subsection{Other options}
+%
+%\DescribeOption{strict}
+% Some users will want to stick closely to the official rules for
+% typesetting units.  This could be made complicated if the options
+% for non-standards behaviour could not be turned off.  The
+% preamble-only option \opt{strict} resets package behaviour to 
+% follow the rules closely, and disables options which deviate from 
+% this.  If the package is loaded with the \opt{strict} option, all 
+% output is made using the upright serif font.
+% 
+%\subsection{Local configurations}
+%\label{sec:config:local}
+% 
+% The \pkg{siunitx} package will check for a local configuration file
+% \file{siunitx.cfg} during package loading.  This occurs before
+% applying any setting given in the optional argument to 
+% \cs{usepackage}.  A typical configuration file may include 
+% settings (using \cs{sisetup}) and locally-defined units, for
+% example
+%\begin{LaTeXdemo}[code only]
+%  \ProvidesFile{siunitx.cfg}
+%  \sisetup{
+%    output-decimal-marker = {,},
+%    per-mode              = symbol,
+%  }
+%  \DeclareSIUnit\torr{torr}
+%\end{LaTeXdemo}
+% As units are always declared, overwriting any existing definition,
+% units may safely be created in the configuration file even when also
+% included in individual LaTeX document headers.
+% 
+%\section{Hints for using \pkg{siunitx}}   
+% 
+%\subsection{Ensuring text or math output}
+%
+% The macros \cs{ensuremath} and \cs{text} should be used to ensure that
+% a particular item is always printed in the desired mode. Some 
+% mathematical output does not work well in \cs{mathrm} (the standard
+% font used by \pkg{siunitx} for printing). The easiest way to solve
+% this is to use the construction "\text{\ensuremath{...}}", which will
+% print the material in the standard mathematics font without affecting
+% the rest of the output. In some cases, simply forcing \cs{mathnormal}
+% will suffice, but this is less reliable with non-Latin characters.
+% 
+%\subsection{Numbers greater than, less than and so forth}
+%
+% The numerical relationships \( > \), \( < \), \emph{etc}.~are
+% not signs, and so the results obtained by using them as such with
+% \pkg{siunitx} are not predictable. The supported method for including
+% relations is to use them outside of numbers:
+%\begin{LaTeXdemo} 
+%  \( \num{1e4} > \num{1e-4} \) \\
+%  \( {>}\SI{34.5}{\metre} \)
+%\end{LaTeXdemo} 
+% Notice the extra braces in the second example line, needed to
+% prevent TeX including more space around the \( > \).
+% 
 %\subsection{Expanding content in tables}
-% When processing |S| columns, \currpkg works hard to expand any
-% items which may give numbers.  So for example you can define values
-% as macros (\ref{tab:vmacros}). To avoid the expansion of single
-% macros, you must either wrap them in two sets of braces or make
-% them robust (using either \cs{DeclareRobustCommand} or
-% \cs{protected}).
-%\begin{LaTeXexample}[float]
+%
+% When processing tables, \pkg{siunitx} will expand anything stored
+% inside a macro, unless it is long or protected. LaTeX2e robust
+% commands are also detected and are not expanded 
+% (\cref{tab:xmpl:macro}). Values which would otherwise be expanded
+% can be protected by wrapping them in a set of braces. As TeX itself
+% will expand the first token in a table cell before \pkg{siunitx}
+% can act on it, using the e-TeX protected mechanism is the 
+% recommended course of action to prevent expansion of macros in
+% table cells. (As is shown in the table, TeX's expansion of
+% LaTeX2e robust commands can lead to unexpected results.)
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
 %    \centering
-%    \caption{Values as macros}
-%    \label{tab:vmacros}
-%    \newcommand*{\myvala}{1.234}%
-%    \newcommand*{\myvalb}{20.345}%
-%    \newcommand*{\myvalc}{0.987654}%
-%    \DeclareRobustCommand*{\myvald}{88.88}%
-%    \begin{tabular}{S[tabtextalign=left]}
+%    \caption{Values as macros in \texttt{S} columns.}
+%    \label{tab:xmpl:macro}
+%    \newcommand*\myvaluea{1234}
+%    \newcommand\myvalueb{1234}
+%    \DeclareRobustCommand*\myvaluec{1234}
+%    \protected\def\myvalued{1234}
+%    \begin{tabular}{S}
 %    \toprule
-%    {Some Values} \\
+%      {Some Values} \\
 %    \midrule
-%    \myvala  \\
-%    \myvalb \\
-%    \myvalc \\
-%    {{\myvala}} \\
-%    \myvald \\
+%       \myvaluea  8.8 \myvaluea  \\ % Both expanded
+%       \myvalueb  8.8 \myvalueb  \\ % First expanded by TeX
+%                                    % to numbers
+%       \myvaluec  8.8 \myvaluec  \\ % First expanded by TeX
+%                                    % but not to numbers!
+%       \myvalued  8.8 \myvalued  \\ % Neither expanded
+%      {\myvaluea\ 8.8 \myvaluea} \\ % Neither expanded
 %    \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
+%\end{LaTeXdemo}
 %
 % It is possible to use calculated values in tables. For this to
 % work, the calculation must take place before attempting to parse
-% the number. This means that any calculation code should be wrapped
-% in braces and appear before the use of the number. This is
-% illustrated by using the \pkg{datatool} package to set up a
-% miniature database, and then output the values doubled
-% (\ref{tab:calc}). This example also shows that macros such as
-% \cs{DLTforeach}, which construct a table while \TeX\ is running,
-% cannot be placed inside an |S| column (or an |s| one). Instead, an
-% additional dummy column has been added with no inter-column space.
-% This is used to contain the tale-building macro.
-%\begin{LaTeXexample}[float]
+% the number. An added complication is that TeX itself will
+% expand the first macro in a table cell until it finds 
+% something unexpandable. The e-TeX protected mechanism can be
+% used to prevent this; using the \pkg{etoolbox} package provides
+% a convenient way to apply this protection to existing functions.
+% The general approach is illustrated in \cref{tab:xmpl:calc}.
+% The macro \cs{DTLmul} is made robust inside the table using
+% the \cs{robustify} command from \pkg{etoolbox}, before 
+% constructing the table using an extra column to contain the
+% calculation.
+%\begin{LaTeXdemo}[code and float]
 %  \DTLnewdb{data}
 %  \DTLnewrow{data}\DTLnewdbentry{data}{value}{66.7012}
 %  \DTLnewrow{data}\DTLnewdbentry{data}{value}{66.0212}
 %  \DTLnewrow{data}\DTLnewdbentry{data}{value}{64.9026}
 %  \begin{table}
-%    \caption{Calculated values}
-%    \label{tab:calc}
+%    \caption{Calculated values.}
+%    \label{tab:xmpl:calc}
 %    \centering
-%    \sisetup{tabformat=2.4}
-%    \begin{tabular}{SS@{}l}
+%    \robustify\DTLmul
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 2,
+%      table-figures-decimal  = 4
+%    }
+%    \begin{tabular}{
+%      S
+%      S[table-figures-integer = 3]
+%      @{}l
+%    }
 %      \toprule
-%      {Value} & {Doubled}  &
+%        {Value} & {Doubled}  &
 %      \DTLforeach{data}{\myvalue=value}{%
 %        \DTLiffirstrow {\\ \midrule}{\\}%
 %        \myvalue & % First column
-%        {\DTLmul{\myvalue}{\myvalue}{2}} \myvalue % second column
+%        \DTLmul{\myvalue}{\myvalue}{2} \myvalue % second column
 %        & }\\
 %      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\subsection{Adding items after the last column of a tabular}
-% If you use an |S| or |s| column as the last one in a tabular, and
-% you use the \pkg{array} ``|<|'' construction to add items after it,
-% the spacing may be wrong.  This will occur if the column contents
-% are of differing widths.  Changing the \LaTeX\ |\\| line ending for
-% the plain \TeX\ \cs{cr} will give the correct spacing, but does not
-% allow adjustment of inter-row distance (\ref{tab:cr}).\footnote{For
-% the \TeX\ experts, the issue here is that the system to gather up
-% cell contents is added in using the \texttt{<} construction.
-% Normally, this comes after the cell contents and any other
-% \texttt{<} arguments, so collects the user additions.  However, in
-% the last cell the contents include \texttt{\bslash\bslash}, which
-% is converted to \cs{cr} before gathering can occur.  By using
-% \cs{cr} directly, the gathering process receives all of the cell
-% contents as normal.}  In most cases, this should not be a serious
-% issue. Notice that an extra set of braces is needed here, compared
-% to usual \LaTeX\ use; this is to prevent any expansion of the
-% material by \currpkg.
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+%
+%\subsection{Using \pkg{siunitx} with \pkg{datatool}}
+%
+% As illustrated in \cref{tab:xmpl:calc}, \pkg{siunitx} can be used
+% to typeset data stored using \pkg{datatool}. For quickly displaying
+% the contents of tables, \pkg{datatool} offers the \cs{DTLshowtable}
+% macro. This will only work with \texttt{S} columns if number parsing
+% is turned off (\cref{tab:xmpl:datatool}).
+%\begin{LaTeXdemo}[code and float]
+%  \DTLnewdb{moredata}
+%  \DTLnewrow{moredata}\DTLnewdbentry{moredata}{value}{ 6.7012}
+%  \DTLnewrow{moredata}\DTLnewdbentry{moredata}{value}{66.0212}
+%  \DTLnewrow{moredata}\DTLnewdbentry{moredata}{value}{64.902 }
 %  \begin{table}
-%    \caption{Correcting spacing in last \texttt{S} column}
-%    \label{tab:cr}
-%    \hfil
-%    \begin{tabular}{S<{{\,\si{\kg}}}S<{{\,\si{\kg}}}}
-%      \toprule
-%      \multicolumn{1}{c}{Long header} &
-%        \multicolumn{1}{c}{Long header} \\
-%      \midrule
-%      1.23 & 1.23 \\
-%      4.56 & 4.56 \\
-%      7.8  & 7.8  \\
-%      \bottomrule
-%    \end{tabular}
-%    \hfil
-%    \begin{tabular}{S<{{\,\si{\kg}}}S<{{\,\si{\kg}}}}
-%      \toprule
-%      \multicolumn{1}{c}{Long header} &
-%        \multicolumn{1}{c}{Long header} \\
-%      \midrule
-%      1.23 & 1.23 \cr
-%      4.56 & 4.56 \cr
-%      7.8  & 7.8  \cr
-%      \bottomrule
-%    \end{tabular}
-%    \hfil
+%    \caption{Displaying a \textsf{datatool} table.}
+%    \label{tab:xmpl:datatool}
+%    \centering
+%    \sisetup{
+%      parse-numbers          = false,
+%      table-number-alignment = center,
+%      table-figures-integer  = 2,
+%      table-figures-decimal  = 4
+%    }
+%    \renewcommand*\dtlrealalign{S}
+%    \DTLdisplaydb{moredata}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\subsection{Using \currpkg\ with the \pkg{cellspace} package}
-% Both \currpkg\ and \pkg{cellspace} use the letter \texttt{S} for a 
+%\end{LaTeXdemo}
+% 
+%\subsection{Using units such as \si{\micro\metre\per\second} in 
+%  headings}
+%
+% The \pkg{siunitx} code is designed to work correctly with functions 
+% in headings. They will print correctly in headings and in the table
+% of contents. As illustrated here, the standard behaviour is to ignore
+% font changes. When the \pkg{hyperref} package is loaded, the
+% functions automatically \enquote{degrade gracefully} to produce 
+% useful information in PDF bookmarks. If you want more control over
+% the bookmark text, use the \cs{texorpdfstring} function from 
+% \pkg{hyperref}, for example:
+%\begin{LaTeXdemo}[code only]
+%  \section{Some text 
+%    \texorpdfstring
+%      {\si{\joule\per\mole\per\kelvin}}
+%      {J mol-1 K-1}%
+%    }
+%\end{LaTeXdemo}
+%
+%\subsection{Symbols and XeTeX}
+%
+% A small number of non-Latin symbols are needed by \pkg{siunitx},
+% notably \SIUnitSymbolOhm\ and \SIUnitSymbolMicro. The package picks
+% glyphs for these which are correct in the sense that they are upright
+% (not italic) symbols, and match the LaTeX standard Computer Modern
+% font. However, this does not make them the best choice if other
+% fonts are in use, which is particularly common when XeTeX is 
+% being used. 
+% 
+% XeTeX users will probably need to choose appropriate symbols 
+% themselves. The correct choice depends on the fonts in use, but many
+% system fonts include Greek letters and other symbols (which is not
+% the case with most TeX-specific fonts). An appropriate setting
+% could then be to use the text \SIUnitSymbolMicro\ symbol in all
+% cases:
+%^^A This document cannot be UTF-8, as it has to work correctly with
+%^^A pdfLaTeX. So there is a bit of work to do here to get the right
+%^^A output.
+%\begin{flushleft}
+%  \ttfamily
+%  \textbackslash \textcolor{blue}{sisetup}\{\\
+%  \ \ math-micro  = \textbackslash 
+%    \textcolor{blue}{text}\{\SIUnitSymbolMicro\}, \\
+%  \ \ text-micro \ = \SIUnitSymbolMicro \\
+%  \}
+%\end{flushleft}
+%
+%\subsection{Scaled document fonts with XeTeX}
+%
+% The \pkg{fontspec} package makes it possible to scale the document
+% body font. This can lead to unexpected problems with printing 
+% for \pkg{siunitx}, as some symbols will not scale while numbers
+% and text will. The problem is best avoided by forcing \pkg{siunitx}
+% to use the default math font for all output:
+%\begin{LaTeXdemo}[code only]
+%  \sisetup{
+%    mode    = math,
+%    math-rm = \ensuremath
+%  }
+%\end{LaTeXdemo}
+% This will cause all \pkg{siunitx} output \emph{not} to scale at all,
+% consistent with other mathematical content.
+% 
+% \subsection{Interaction with \pkg{tex4ht}}
+%
+% \pkg{siunitx} will detect when \pkg{tex4ht} is in use, and makes 
+% some changes to the way output is printed. Text mode printing is
+% automatically selected, and certain items (such as spaces) are
+% printed in text mode rather than as math. This is designed to 
+% reduce the likelihood of spurious formulae appearing in, for
+% example, output converted to OpenOffice format.
+%
+%\subsection{Maximising performance}
+%
+% Both the number and unit parsers require significant effort in
+% terms of TeX programming. For input that does not require 
+% such processing, the maximum performance for \pkg{siunitx} can
+% therefore be obtained by turning off both systems:
+%\begin{LaTeXdemo}
+%  \SI{7.3}{\Hz} \\
+%  \SI[parse-units = false]{7.3}{\Hz} \\
+%  \SI[
+%    parse-numbers = false,
+%    parse-units   = false
+%  ]{7.3}{\Hz} 
+%\end{LaTeXdemo}
+%
+%\subsection{Transferring settings to \pkg{pgf}}
+%
+%\DescribeMacro{\SendSettingsToPgf}
+% The numerical engine in the \pkg{pgf} package has settings similar
+% to those in \pkg{siunitx}. To enable working with both packages
+% easily, the macro \cs{SendSettingsToPgf} is available. It will
+% set some commonly-used numerical formatting options in \pkg{pgf}
+% to the current values used by \pkg{siunitx} to make using the 
+% two packages together more convenient for end users. This
+% function can be used at any point after loading both the 
+% \pkg{pgf} and \pkg{siunitx} packages.
+%\begin{LaTeXdemo}[code only]
+%  \documentclass{article}
+%  \usepackage{pgf,siunitx}
+%  \sisetup{...}
+%  \SendSettingsToPgf
+%  ...
+%\end{LaTeXdemo} 
+%
+%\subsection{Using \pkg{siunitx} with the \pkg{cellspace} package}
+%
+% Both \pkg{siunitx} and \pkg{cellspace} use the letter \texttt{S} for a 
 % new column type. This obviously leads to a problem. If both are 
-% loaded, \currpkg\ will retain the \texttt{S} column, and moves the
+% loaded, \pkg{siunitx} will retain the \texttt{S} column, and moves the
 % functionality of \pkg{cellspace} to the letter \texttt{C}. This 
 % allows the normal use of \pkg{cellspace} with standard column types:
-% it does \emph{not} work with the \currpkg\ \texttt{S} or \texttt{s}
-% columns.
-% 
-%\subsection{Using \currpkg\ with the \pkg{mathabx} package}
-%\changes{v1.1g}{2008/11/26}{Respect loading of \pkg{mathabx}}
-% The \pkg{mathabx} package defines its own \cs{second} and 
-% \cs{degree} macros.  This is respected by \currpkg: if you want the
-% \currpkg\ definitions instead, put the lines
-%\begin{LaTeXexample}[noexample]
-%  \makeatletter
-%  \renewunit{\second}{s}
-%  \renewunit[valuesep=none]{\degree}{\si@sym@degree}
-%  \makeatother
-%\end{LaTeXexample}
-% after |\begin{document}|.
-% 
-%\subsection{Numbers with no mantissa in \texttt{S} columns}
-% The \texttt{S} column is design for handling numbers which will 
-% contain a decimal symbol. The current code deals unreliably with
-% numbers which consist only of an exponent part. This is on the
-% list for version 2 of \pkg{siunitx}: the current code makes this issue
-% difficult to fix without major changes.
-%
-%\iffalse
-%<*bug>
-%\fi
-%\section{Reporting a problem}
-% \currpkg is quite long and complicated, and works hard to cover all
-% possible eventualities.  However, there will be bugs in the code
-% and unexpected interactions with other packages.  If you think you
-% have found a bug, please report it.  A short test-case
-% demonstrating the problem would be very welcome.  The following is
-% a suitable template, and is available as \file{si-bug.ltx} in the
-% \texttt{doc/latex/siunitx} directory or by running the \ext{dtx} or
-% \ext{ins} file through \TeX.
-%    \begin{macrocode}
-\listfiles
-\documentclass{article}
-%    \end{macrocode}
-% Load other packages needed here.
-%    \begin{macrocode}
-\usepackage{siunitx}
-%    \end{macrocode}
-% Normally, debugging the load procedure will not be needed; the
-% debug option here means that all run-time information is logged.
-%    \begin{macrocode}
-\sisetup{debug}
-\begin{document}
-This is the bug test-case document for the \textsf{siunitx}
-package.\\
-Please put your demonstration here, and e-mail to the package
-author.
-\begin{center}
-  \texttt{joseph.wright@morningstar2.co.uk}
-\end{center}
-\end{document}
-%    \end{macrocode}
-%\iffalse
-%</bug>
-%\fi
-%
-%\section{Feature requests}
-% Feature requests for \currpkg are welcome.  The package maintainer
-% will consider any ideas within the remit of the package (units and
-% values).  If suggesting a new feature, an example of how it should
-% work would be appreciated.  If new controls are needed, some
-% suggestions for option names would be welcome.
-%
-%\section{Acknowledgements}
-% Many thanks indeed to Stefan Pinnow, who has made a very large
-% number of suggestions and found numerous bugs in the package.  His
-% contribution to the package has been vital. The package author has
-% learned \LaTeX\ tricks from far too many people to thank all of
-% them.  However, for this package specific thanks must go to the
-% authors of the existing ``unit'' packages: Danie Els (\SIstyle),
-% Marcel Heldoorn (\SIunits), Patrick Happel (\unitsdef), Axel
-% Reichert (\units) and Harald Harders (\numprint).  Will Robertson
-% and Heiko Oberdiek deserve much credit for demonstrating \LaTeX\
-% coding best practice. Victor Eijkhout's excellent (and free)
-% \emph{\TeX\ by Topic} has provided some useful coding hints
-% \cite{Eijkhout}.  The idea for combining and extending unit
-% provision in \LaTeX\ was heavily inspired by Philip Lehmann's
-% \pkg{biblatex}. Thanks to the various contributors of ideas for the
-% package: Donald Arseneau, Michele Dondi, Paul Gans, Ben Morrow, Lan
-% Thuy Pham, Alan Ristow, Patrick Heinze, Andrea Blomenhofer, Morten
-% H{\o}gholm, Burkhard Moddemann  and Patrick Steegstra.
-%
-%\clearpage
-%\part{Correct application of (SI) units}
-%\section{Background}
+% it does \emph{not} work with the \pkg{siunitx} \texttt{S} or 
+% \texttt{s} columns.
+%
+%\section{Correct application of (SI) units}
+%
 % Consistent and logical units are a necessity for scientific work,
 % and have applicability everywhere.  Historically, a number of
 % systems have been used for physical units.  SI units were
-% introduced by the \latin{Conf\'erence G\'en\'erale des Poids et
+% introduced by the \emph{Conf{\'e}rence G{\'e}n{\'e}rale des Poids et
 % Mesures} (CGPM) in 1960.  SI units are a coherent system based on
 % seven base units, from which all other units may be derived.
 %
@@ -2985,241 +3327,211 @@ author.
 % As befits an agreed international standard, the full rules are
 % detailed. It is not appropriate to reproduce these in totality
 % here; instead, a useful summary of the key points is provided. The
-% full details are available from the \latin{Bureau International des
-% Poids et Mesures} (BIPM) in French \cite{BIPM:FR} and English
-% \cite{BIPM:EN}.  They also publish a very useful and detailed guide
-% to using units, values and so on, available online in a number of
-% different formats \cite{BIPM:PDF}.
-%
-% \currpkg takes account of the information given here, so far as is
-% possible.  Thus the package defaults follow the recommendations
+% full details are available from the \emph{Bureau International des
+% Poids et Mesures} \cite{BIPM}.
+%
+% \pkg{siunitx} takes account of the information given here, so far as 
+% is possible.  Thus the package defaults follow the recommendations
 % made for typesetting units and values.  Spacing and so forth is
 % handled in such a way as to make implementing the rules
 % (relatively) easy.
 %
-%\section{Units}
-%\subsection{SI base units}
-% There are seven base SI units, listed in \ref{tab:baseunits}. Apart
-% from the kilogram, these are defined in terms of a measurable
+%\subsection{Units}
+%
+% There are seven base SI units, listed in \cref{tab:unit:base}. 
+% Apart from the kilogram, these are defined in terms of a measurable
 % physical quantity needing the definition alone.\footnote{Some base
 % units need others defined first; there is therefore a required
 % order of definition.}  The base units have been chosen such that
 % all physical quantities can be expressed using an appropriative
 % combination of these units, needing no others and with no
 % redundancy.  The kilogram is slightly different from the other base
-% units as it is still defined in terms of a ``prototype'' held in
-% Paris.\footnote{At the time of writing, this is under review and
-% will be altered.}
+% units as it is still defined in terms of a \enquote{prototype} held in
+% Paris.
 %
-%\subsection{SI derived units}
-% All other units within the SI system are regarded as ``derived''
+% All other units within the SI system are regarded as \enquote{derived}
 % from the seven base units.  At the most basic, all other SI units
 % can be expressed as combinations of the base units.  However, many
-% units (listed in \ref{tab:derived}, \ref{tab:experimental} and
-% \ref{tab:accepted}) have a special name and symbol.\footnote{The
-% nautical mile has a given name but no agreed symbol, and although
-% accepted by the SI is not provided by \currpkg as a unit macro.}
-% Most of these units are simple combinations of one or more base
-% units (raised to powers as appropriate).  A small number of units
-% derived from experimental data are allowed as SI units
-% (\ref{tab:experimental}).
-%
-% Some of these units (in \ref{tab:accepted}) are regarded as only
-% ``temporarily'' accepted, as the use of only the base and
-% fully-consistent derived units in \ref{tab:derived} is encouraged.
-% They are accepted as they are in common use in one or more
-% disciplines; some are still very widespread in the appropriate
-% areas.  These units are mainly multiples of base units (for
-% example, a tonne is \SI{1000}{\kilo\gram}).
-%
-% One point to note is that ``unitless ratios'' are regarded as
-% having base units which cancel out.  For example, the radian is
-% regarded as having base unit \si{\metre\per\metre}.  The result of
-% this division (``$1$'') is therefore regarded as a derived SI unit
-% in this context.
-%
-%\subsection{SI prefixes}
-% A series of SI prefixes for decimal multiples and submultiples are
+% units (listed in \cref{tab:unit:derived,tab:unit:accepted}) have a 
+% special name and symbol. Most of these units are simple combinations 
+% of one or more base units (raised to powers as appropriate).  A small
+% number of units derived from experimental data are allowed as SI
+% units (\cref{tab:unit:physical}).
+%
+% A series of SI prefixes for decimal multiples and sub-multiples are
 % provided, and can be used as modifiers for any SI unit (either base
 % or derived units) with the exception of the kilogram.  The prefixes
-% are listed in \ref{tab:prefix}.  No space should be used between a
-% prefix and the unit, and only a single prefix should be used.  Even
-% the degree Celsius can be given a prefix, for example
-% \SI{1}{\milli\celsius}.  The only exception to this rule is for
-% degrees, minutes and seconds of an arc: \ang{1;2;3}.
+% are listed in \cref{tab:unit:prefix}.  No space should be used 
+% between a prefix and the unit, and only a single prefix should be 
+% used.  Even the degree Celsius can be given a prefix, for example
+% \SI{1}{\milli\degreeCelsius}. 
 %
 % It is important to note that the kilogram is the only SI unit with
 % a prefix as part of its name and symbol.  Only  single prefix may
 % be used, and so in the case of the kilogram prefix names are used
-% with the unit name ``gram'' and the prefix symbols are used with
-% the unit symbol \si{\gram}.  For example $\SI{1e-6}{\kilogram} =
-% \SI{1}{\milli\gram}$.
-% 
-% Three unit-prefix combinations deserve special note. The units
-% hectare, kilohm and megohm elide the additional vowel (these
-% would otherwise be hectoare, kiloohm and megaohm).  All other
-% vowel combinations are retained.\footnote{Thanks to Charles
-% Cameron for raising this issue with the package author.}
+% with the unit name \enquote{gram} and the prefix symbols are used with
+% the unit symbol \si{\gram}.  For example 
+% \( \SI[prefixes-as-symbols = false]{1}{\milli\gram} =
+% \SI{1}{\milli\gram} \).
 %
-%\subsection{Other units}
 % The application of SI units is meant to provide a single set of
 % units which ensure consistency and clarity across all areas.
 % However, other units are common is many areas, and are not without
-% merit. The units provided by \currpkg by default do not included
+% merit. The units provided by \pkg{siunitx} by default do not include
 % any of these; only units which are part of the SI set or are
 % accepted for use with SI units are defined.  However, several other
 % sets of units can be loaded as optional modules. The binary
-% prefixes and units (Section~\ref{sec:binary} and \ref{tab:binary})
-% are the most obvious example.  These are \emph{not} part of the SI
-% specifications, but the prefix names are derived from those in
-% \ref{tab:prefix}.
-%
-% Other units (such as those provided by the modules \opt{synchem},
-% \opt{hep} and \opt{astro}) are normally to be avoided where
-% possible.  SI units should, in the main, be preferred due to the
-% advantages of clear definition and self-consistency this brings.
-% However, there will probably always be a place for specialist or
-% non-standard units.  This is particulary true of units derived from
-% basic physical constants; for example reason, the \opt{hep} module
-% defines the speed of light, \si{\clight}, as a unit.  For work in
-% basic science, a small number of physical constants are recognised
-% as units provided the results for comparison with experiment are
-% given in SI units.
+% prefixes and units (\cref{tab:unit:binary}) are the most obvious 
+% example.  These are \emph{not} part of the SI specifications, but the 
+% prefix names are derived from those in \cref{tab:unit:prefix}.
+%
+% Other units are normally to be avoided where possible.  SI units 
+% should, in the main, be preferred due to the advantages of clear
+% definition and self-consistency this brings. However, there will 
+% probably always be a place for specialist or non-standard units.  
+% This is particularly true of units derived from basic physical
+% constants.
 %
 % There are also many areas where non-standard units are used so
 % commonly that to do otherwise is difficult or impossible.  For
 % example, most synthetic chemists measure the pressure inside vacuum
 % apparatus in \si{\mmHg}, partly because the most common gauge for
 % the task still uses a column of mercury metal.  For these reasons,
-% \currpkg does define non-SI units.
+% \pkg{siunitx} does define non-SI units.
 %
-%\section{Units and values in print}
 %\subsection{Mathematical meaning}
-% As explained earlier, a unit--value combination is a single
+%
+% As explained earlier, a number--unit combination is a single
 % mathematical entity.  This has implications for how both the number
 % and the unit should be printed.  Firstly, the two parts should not
 % be separated.  With the exception of the symbols for plane angles
-% (\si{\degree}, \si{\arcmin} and \si{\arcsec}), it is usual to have
-% a space between the unit and the value.  This should therefore be a
-% non-breaking space between the two.  Different geographical areas
-% have different conventions on the size of this space; a ``small''
-% space (|\,|) is the \currpkg default.
-%\begin{LaTeXexample}
+% (\si{\degree}, \si{\arcminute} and \si{\arcsecond}), it is usual to 
+% have a space between the unit and the value.  This should therefore
+% be a thin non-breaking space between the two.
+%\begin{LaTeXdemo}
 %  A space for \SI{10}{\percent}\\
-%  and also for \SI{100}{\celsius}\\
+%  and also for \SI{100}{\degreeCelsius}\\
 %  but not for \ang{1.23}.
-%\end{LaTeXexample}
+%\end{LaTeXdemo}
 %
 % The mathematical meaning of units also means that the shape, weight
 % and family are important.  Units are supposed to be typeset in an
 % upright, medium weight serif font.  Italic, bold and sans serif are
-% all used mathematically to convey other meanings.  \currpkg package
-% defaults again follow this convention: any local settings are
-% ignored, and uses the current upright serif maths font.  However,
+% all used mathematically to convey other meanings.  The \pkg{siunitx} 
+% package defaults again follow this convention: any local settings are
+% ignored, and uses the current upright serif math font.  However,
 % there are occasions where this may not be the most desirable
 % behaviour.  A classic example would be in an all-bold section
 % heading.  As the surrounding text is bold, some people feel that
 % any units should follow this.
-%\begin{LaTeXexample}
+%\begin{LaTeXdemo}
 %  Units should \textbf{not be bold: \SI{54}{\farad}}\\
 %  \textbf{But perhaps in a running block,\\
-%  it might look better: \SI[obeybold]{54}{\farad}}
-%\end{LaTeXexample}
+%  it might look better: \SI[detect-weight]{54}{\farad}}
+%\end{LaTeXdemo}
 %
-%\subsection{Unit multiplication and division}
 % Symbols for units formed from other units by multiplication are
 % indicated by means of either a half-height (that is, centred) dot
-% or a (thin) space.  This document uses a half-height dot as
-% (\emph{i}) this is the recommendation of \textsc{nist}, amongst
-% others and (\emph{ii}) it avoids potential confusion between unit
-% prefixes and multiplied units.
-%\begin{LaTeXexample}
-%  $\si{\metre\second} = \mbox{metre second}$ \\
-%  $\si{\milli\second} = \mbox{millisecond}$ \\
-%  \sisetup{unitsep=thin}
-%  $\si{\metre\second} = \mbox{metre second}$ \\
-%  $\si{\milli\second} = \mbox{millisecond}$
-%\end{LaTeXexample}
-% There are some circumstances under which it is permissable to omit
+% or a (thin) space. 
+%\begin{LaTeXdemo}
+%  \( \si{\metre\second} = \text{metre second} \) \\
+%  \( \si{\milli\second} = \text{millisecond}  \) \\
+%  \sisetup{inter-unit-separator = { } \cdot { } }
+%  \( \si{\metre\second} = \text{metre second} \) \\
+%  \( \si{\milli\second} = \text{millisecond}  \)
+%\end{LaTeXdemo}
+% There are some circumstances under which it is permissible to omit
 % any spaces.  The classic example is \si{\kWh}, where
-% ``\si[unitsep=thin]{\kWh}'' does not add any useful information.
-% If using such a unit repeatedly, users of \currpkg are advised to
-% create a custom unit to ensure consistency.\footnote{\cs{kWh} and
-% \cs{kilowatthour} are defined by \currpkg in this way.}
+% \enquote{\si[inter-unit-separator = \,]{\kWh}} does not add any 
+% useful information. If using such a unit repeatedly, users of 
+% \pkg{siunitx} are advised to create a custom unit to ensure 
+% consistency.
 %
 % Symbols for units formed from other units by division are indicated
-% by means of a virgule (oblique stroke, slash, |/|), a horizontal
+% by means of a virgule (oblique stroke, slash, "/"), a horizontal
 % line, or negative exponents.\footnote{Notice that a virgule and a
 % solidus are not the same symbol.}  However, to avoid ambiguity, the
 % virgule must not be repeated on the same line unless parentheses
-% are used. This is ensured when using named unit macros in \currpkg,
-% which will ``trap'' repeated division and format it correctly.  In
-% complicated cases, negative exponents are to be preferred over
-% other formats.
-%\begin{LaTeXexample}
+% are used. This is ensured when using named unit macros in 
+% \pkg{siunitx}, which will \enquote{trap} repeated division and format
+% it correctly.  In complicated cases, negative exponents are to be
+% preferred over other formats.
+%\begin{LaTeXdemo}
 %  \si{\joule\per\mole\per\kelvin}\\
-%  \si[per=fraction]{\joule\per\mole\per\kelvin}\\
-%  \si[per=slash]{\joule\per\mole\per\kelvin}
-%\end{LaTeXexample}
+%  \si[per-mode = fraction]{\joule\per\mole\per\kelvin}\\
+%  \si[per-mode = symbol]{\joule\per\mole\per\kelvin}
+%\end{LaTeXdemo}
 %
-%\subsection{Repeating units}
 % Products and errors should show what unit applies to each value
-% given.  Thus \SI{2x3}{\metre} is an ordered set of lengths of a
-% geometric area, whereas \SI[repeatunits=false]{2x3}{\metre} is a
-% length (and equal to \SI{6}{\metre}). Thus, $\times$ is not a
-% product but is a mathematical operator; in the same way, a $2
-% \times 3$ matrix is not a $6$ matrix!  In some areas, areas and
-% volumes are given with separated units but a unit raised to the
-% appropriate power: \SI[repeatunits=power]{2 x 3}{\metre}. Although
-% this does display the correct overall units, it is
-% potentially-confusing and is not encouraged.
-%
-%\subsection{Clarity in writing values of quantities}
+% given.  Thus \SI[product-units = brackets]{2x3}{\metre} is an 
+% ordered set of lengths of a geometric area, whereas 
+% \SI[product-units = single]{2x3}{\metre} is a length (and equal 
+% to \SI{6}{\metre}). Thus,  \(\times\) is not a product but is a 
+% mathematical operator; in the same way, a \(2 \times 3\) matrix is not
+% a \(6\) matrix! In some areas, areas and volumes are given with 
+% separated units but a unit raised to the appropriate power: 
+% \SI[product-units = power]{2 x 3}{\metre}. Although this does 
+% display the correct overall units, it is potentially-confusing and is
+% not encouraged.
+%
 % Care must be taken when writing ranges of numbers.  For purely
 % numerical values, it is common to use a en-dash between values, for
-% example ``see pages 1--5''.  On the other hand, values with units
-% could be misinterpret as negative values if written in this way. As
-% the unit--value combination is a single mathematic entity, writing
-% the values with an en-dash followed by a single unit is also
-% incorrect.  As a result, using the word ``to'' is strongly
+% example \enquote{see pages 1--5}.  On the other hand, values with 
+% units could be misinterpret as negative values if written in this 
+% way. As the unit--value combination is a single mathematical entity, 
+% writing the values with an en-dash followed by a single unit is also
+% incorrect.  As a result, using the word \enquote{to} is strongly
 % recommended.
-%\begin{LaTeXexample}
-%  \SI{1}{\metre} to \SI{5}{\metre} long.
-%\end{LaTeXexample}
+%\begin{LaTeXdemo}
+%  \SIrange{1}{5}{\metre} long.
+%\end{LaTeXdemo}
 %
 %\subsection{Graphs and tables}
+%
 % In graphs and tables, repetition of the units following each entry
 % or axis mark is confusing and repetitive.  It is therefore best to
 % place the unit in the label part of the information.  Placing the
 % unit in square brackets is common but mathematically
-% poor.\footnote{For example, for an acceleration $a$, the expression
-% $[a]$ is the dimensions of $a$, \ie length per time squared in this
-% case.}  Much better is to show division of all values by the unit,
-% which leaves the entries as unitless ratios.  This is illustrated
-% in \ref{tab:label} and \ref{fig:label}.
-%\begin{LaTeXexample}[float]
+% poor.\footnote{For example, for an acceleration \(a\), the expression
+% \([a]\) is the dimensions of \(a\), \emph{i.e.}~length per time 
+% squared in this case.}  Much better is to show division of all 
+% values by the unit, which leaves the entries as unitless ratios.  
+% This is illustrated in \cref{tab:xmpl:unitless} and 
+% \cref{fig:xmpl:unitless}.
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
 %    \centering
-%    \caption{An example of table labelling}
-%    \label{tab:label}
-%    \begin{tabular}{cS[tabformat=1.4,tabnumalign=centre]}
+%    \caption{An example of table labelling.}
+%    \label{tab:xmpl:unitless}
+%    \sisetup{
+%      table-number-alignment = center,
+%      table-figures-integer  = 1,
+%      table-figures-decimal  = 4
+%    }
+%    \begin{tabular}{cS}
 %      \toprule
-%      {Entry} & {Length/\si{\metre}} \\
+%        Entry & {Length/\si{\metre}} \\
 %      \midrule
-%      1 & 1.1234 \\
-%      2 & 1.1425 \\
-%      3 & 1.7578 \\
-%      4 & 1.9560 \\
+%        1 & 1.1234 \\
+%        2 & 1.1425 \\
+%        3 & 1.7578 \\
+%        4 & 1.9560 \\
 %      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%\begin{LaTeXexample}[float]
+%\end{LaTeXdemo}
+%\begin{LaTeXdemo}[code and float]
 %  \begin{figure}
 %    \centering
 %    \begin{tikzpicture}
-%      \begin{axis}[xlabel=$t/\si{\second}$,ylabel=$d/\si{\metre}$]
-%        \addplot[smooth,mark=x]
+%      \begin{axis}[
+%        xlabel = \( t/\si{\second} \),
+%        xmax   = 6,
+%        xmin   = 0,
+%        ylabel = \( d/\si{\metre}  \),
+%        ymin   = 0
+%      ]
+%        \addplot[smooth,mark=*]
 %          plot coordinates {
 %            (0,0)
 %            (1,5)
@@ -3231,855 +3543,259 @@ author.
 %           };
 %      \end{axis}
 %    \end{tikzpicture}
-%    \caption{An example of graph labelling}
-%    \label{fig:label}
+%    \caption{An example of graph labelling.}
+%    \label{fig:xmpl:unitless}
 %  \end{figure}
-%\end{LaTeXexample}
+%\end{LaTeXdemo}
 %
 % In most cases, adding exponent values in the body of a table is
 % less desirable than adding a fixed exponent to column headers.  An
-% example is shown in \ref{tab:exp}.  The use of \cs{multicolumn} is
-% needed here due to the ``|<|''; without \cs{multicolumn}, the
-% titles are followed by ``\si{\kilo\gram}''!
-%\begin{LaTeXexample}[float]
+% example is shown in \cref{tab:good}.  The use of \cs{multicolumn} is
+% needed here due to the \enquote{\texttt{<}}; without \cs{multicolumn}, 
+% the titles are followed by \enquote{\si{\kilo\gram}}!
+%\begin{LaTeXdemo}[code and float]
 %  \begin{table}
 %    \centering
-%    \caption{Good and bad columns}
-%    \label{tab:exp}
-%    \sisetup{tabnumalign=centre}
+%    \caption{Good and bad columns.}
+%    \label{tab:good}
+%    \sisetup{table-number-alignment = center}
 %    \begin{tabular}{
 %      c
-%      S[tabformat=1.3e1]<{{\,\si{\kilogram}}}
-%      S[tabformat=2.2]}
+%      S[
+%        table-figures-integer  = 1,
+%        table-figures-decimal  = 3,
+%        table-figures-exponent = 1
+%      ]
+%      @{\,\si{\kilogram}}
+%      S[
+%        table-figures-integer  = 2,
+%        table-figures-decimal  = 2
+%      ]
+%    }  
 %      \toprule
-%      Entry & \multicolumn{1}{c}{Mass} &
-%        {Mass/\SI{e3}{\kilogram}} \\
+%        Entry & \multicolumn{1}{c}{Mass} &
+%          {Mass/\SI{e3}{\kilogram}} \\
 %      \midrule
-%      1 & 4.56e3  & 4.56 \\
-%      2 & 2.40e3  & 2.40 \\
-%      3 & 1.345e4 & 13.45 \\
-%      4 & 4.5e2   & 0.45 \\
+%        1 & 4.56e3  & 4.56 \\
+%        2 & 2.40e3  & 2.40 \\
+%        3 & 1.345e4 & 13.45 \\
+%        4 & 4.5e2   & 0.45 \\
 %      \bottomrule
 %    \end{tabular}
 %  \end{table}
-%\end{LaTeXexample}
-%
-%\bibliographystyle{unsrt}
-%\StopEventually{%
-%  \clearpage
-%  \part{Notes}
-%  \PrintChanges
-%  \PrintIndex
-%  \bibliography{siunitx}}
+%\end{LaTeXdemo}
+%
+%\section{Making suggestions and reporting bugs}
+%
+% Feedback on \pkg{siunitx} is always welcome, either to make 
+% suggestions or to report problems. When sending feedback, it is
+% always useful if a small example file is included, showing the
+% bug being reported or illustrating the desired output.  It is
+% helpful if a \enquote{reference rendering} is included, showing what
+% the output should look like.  A typical example file might read
+%\begin{LaTeXdemo}[code only]
+%  \listfiles
+%  % Use the article class unless the problem is class-dependent
+%  \documentclass{article}
+%  \usepackage{siunitx}
+%  % Other packages loaded as required
+%  \begin{document}
+%  Reference output: $ 1.23\,\mathrm{m} $
+%  
+%  siunitx output: \SI{1.23}{\metre}
+%  \end{document}
+%\end{LaTeXdemo}
+% As illustrated, it is usually best to use the \texttt{article}
+% class and to only load packages which are needed to show the issue. 
+% It is also useful to include a copy of the log file generate by
+% TeX when reporting a bug (as the versions of packages can be
+% important to solving the issue).
+% 
+% Feedback can be sent in a range of ways.  The development code 
+% is hosted by 
+% \href{http://bitbucket.org/josephwright/siunitx}{BitBucket},
+% and the site includes an issue tracker.  Adding feedback directly
+% to the database means that other users can see it, and also 
+% ensures that it does not get forgotten.  E-mailing directly is 
+% will also definitely get attention:
+% \href{mailto:joseph.wright@morningstar2.co.uk}
+% {\texttt{joseph.wright@morningstar2.co.uk}}. I also keep an eye
+% on various groups, for example 
+% \href{http://groups.google.com/group/comp.text.tex/topics}
+% {\texttt{comp.text.tex}} and 
+% \href{http://www.latex-community.org/forum/}{The LaTeX Community}.
+% Sometimes I miss posts to these places, so it's useful if you also
+% e-mail me pointing to the appropriate thread.
+%
+%\section{Thanks}
+%
+% Many users have provided feedback, bug reports and ideas for new
+% features for \pkg{siunitx}: thanks to all of them. Particular thanks
+% to Stefan Pinnow, who has taken the lead role as beta tester for
+% \pkg{siunitx}, finding incorrect output, bad documentation and the 
+% odd spelling mistake in the documentation. Thanks also to 
+% Danie Els and Marcel Heldoorn for the \pkg{SIstyle} and \pkg{SIunits}
+% packages, respectively, which provided the starting point for the
+% development of \pkg{siunitx}.
+%
+%\end{documentation}
+%
+%\begin{implementation}
+%
+%\section{Implementation}
 %
-% \iffalse
+%    \begin{macrocode}
 %<*package>
-% \fi
+%    \end{macrocode}
 %
-%\clearpage
-%\part{Implementation}
-%\section{Main package}
-% Much of the code here is taken, with little or no modification,
-% from the existing packages.  These are all released under the LPPL,
-% and so this use is entirely allowed.  Rather than confuse the
-% source here with repeated references, note that code here could be
-% copied from \SIstyle, \SIunits, \numprint, \unitsdef or \units.
-% Some ideas have also been borrowed from \pkg{biblatex}; again these
-% will not be specifically noted. Code from other packages will be
-% marked when used.
-%
-% User-space commands (those not containing |@|) defined here should
-% give the same result as macros with the same name in the older
-% packages.\footnote{Although extra optional arguments may be added.}
-% However, internal package macros will behave differently; if the
-% user has redefined internal macros, then compatibility will be
-% impaired.
-%
-% The code used here uses \LaTeX\ rather than \TeX\ commands where
-% possible.\footnote{This applies to \LaTeX\ kernel commands only;
-% for example, \pkg{ifthenelse} is not used.}  For example,
-% \cs{newcommand*} is used in place of \cs{def}, unless custom
-% parameters are needed.  Hopefully, this will aid future
-% maintenance.  Grouping is used where possible to limit the scope of
-% temporary assignments.
-%
-%\subsection{Setup code}
-% As always, the package starts with identification.
-%    \begin{macrocode}
-\NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{siunitx}
-  [2010/02/22 v1.4c A comprehensive (SI) units package]
-%    \end{macrocode}
-% The package requires \eTeX, so the usual test is made.
-%    \begin{macrocode}
-\begingroup
-  \@ifundefined{eTeXversion}
-    {\PackageError{siunitx}
-       {Not running under e-TeX}
-       {This package requires e-TeX. Try compiling the document
-        with\MessageBreak `elatex' instead of `latex'. When
-        using pdfTeX, try `pdfelatex'\MessageBreak instead of
-        `pdflatex'}%
-     \endgroup\endinput}
-    {\endgroup}
-%    \end{macrocode}
-%\begin{macro}{\si@catcodes}
-% There are circumstances under which some odd category codes might
-% be in place.  The category codes for |{|, |}|, |[|, |]| and |#| are
-% assumed to be okay; if issues arise, this can be altered.  \LaTeX\
-% will have set |@| as a letter on loading \currpkg.
-%    \begin{macrocode}
-\edef\si@catcodes{%
-  \catcode\string`\string ` \the\catcode\string`\`\relax
-  \catcode\string`\string = \the\catcode\string`\=\relax
-  \catcode\string`\string ^ \the\catcode\string`\^\relax
-  \catcode\string`\string _ \the\catcode\string`\_\relax
-  \catcode\string`\string ~ \the\catcode\string`\~\relax
-  \catcode\string`\string : \the\catcode\string`\:\relax
-  \catcode\string`\string - \the\catcode\string`\-\relax
-  \catcode\string`\string + \the\catcode\string`\+\relax
-  \catcode\string`\string ; \the\catcode\string`\;\relax
-  \catcode\string`\string , \the\catcode\string`\,\relax
-  \catcode\string`\string . \the\catcode\string`\.\relax}
-\catcode\string`\` 12\relax
-\catcode`\= 12\relax
-\catcode`\^ 7\relax
-\catcode`\_ 8\relax
-\catcode`\~ \active\relax
-\@makeother{\:}
-\@makeother{\-}
-\@makeother{\+}
-\@makeother{\;}
-\@makeother{\,}
-\@makeother{\.}
-%    \end{macrocode}
-%\end{macro}
-% Packages needed for functionality are loaded.  \pkg{xkeyval}
-% handles the package options, while \pkg{amstext} from the \AMS\
-% bundle is needed for \cs{text}.  \pkg{array} is needed for the new
-% column type for tabular material.  \pkg{xspace} provides ``magic''
-% spacing after macros, if requested.
-%    \begin{macrocode}
-\RequirePackage{xkeyval}[2005/05/07]
-\RequirePackage{amstext,array,xspace}
-%    \end{macrocode}
-%\begin{macro}{\si@tempa}
-%\begin{macro}{\si@tempb}
-%\begin{macro}{\si@tempc}
-% Some scratch commands are defined; apart from where a known value
-% is carried through, these could contain anything.
-%    \begin{macrocode}
-\newcommand*{\si@tempa}{}
-\newcommand*{\si@tempb}{}
-\newcommand*{\si@tempc}{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@switch}
-% Various items will need a switch.  To avoid name pollution, a
-% single switch is defined here; grouping will keep the definition
-% local.
-%    \begin{macrocode}
-\newif\ifsi@switch
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tempboxa}
-%\begin{macro}{\si@tempboxb}
-%\begin{macro}{\si@tempboxc}
-%\begin{macro}{\si@tempboxd}
-% Some boxes are also needed.
-%    \begin{macrocode}
-\newbox\si@tempboxa
-\newbox\si@tempboxb
-\newbox\si@tempboxc
-\newbox\si@tempboxd
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@temptoks}
-% A token register is also handy.
-%    \begin{macrocode}
-\newtoks{\si@temptoks}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@packagecheck}
-%\begin{macro}{\si@blockpkgs}
-%\begin{macro}{\si@checkpkgs}
-% As \currpkg is intended to replace the other unit-management
-% packages, these are tested for before any further processing.  If
-% any are loaded, the package halts compilation; name clashes or
-% unexpected results could occur if this is not tested.  Notice that
-% \SIunits and \SIstyle could be loaded with variable capitalisation
-% (at least on Windows); both possibilities are tested.
-%    \begin{macrocode}
-\newcommand*{\si@blockpkgs}{SIunits,sistyle,siunits,SIstyle,%
-  unitsdef,fancyunits}
-\newcommand*{\si@checkpkgs}{units,hepunits,fancynum}
-\newcommand*{\si@packagecheck}{%
-  \begingroup
-  \@for\si@tempa:=\si@blockpkgs\do{
-    \@ifpackageloaded{\si@tempa}
-      {\PackageError{siunitx}
-         {Package `\si@tempa' incompatible}
-         {The \si@tempa\space package and siunitx are
-          incompatible.\MessageBreak Use the
-          `emulate=\si@tempa' package option when loading
-          siunitx}}
-      {}}
-%    \end{macrocode}
-% Some packages should not cause a clash, but are emulated and would
-% be better handled that way.
-%    \begin{macrocode}
-  \@for\si@tempa:=\si@checkpkgs\do{%
-    \@ifpackageloaded{\si@tempa}
-      {\PackageWarning{siunitx}
-         {Consider loading the siunitx package
-          with\MessageBreak option `emulate=\si@tempa', rather
-          than\MessageBreak loading both \si@tempa\space and
-          siunitx}}
-      {}}
-  \endgroup}
-%    \end{macrocode}
-% The check is carried out on loading and at the beginning of the
-% document, so that packages loaded both before and after \currpkg
-% are caught.
-%    \begin{macrocode}
-\si@packagecheck
-\AtBeginDocument{\si@packagecheck}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ifdefinable}
-%\darg{macro}
-% Using \cs{@ifdefinable} to check macro definitions gives a generic
-% error.  To give something more helpful, \cs{@ifundefined} is used,
-% but this needs some \cs{expandafter} work.  This way it can also be
-% used as a form of \cs{@ifundefined} for macro names.
-%    \begin{macrocode}
-\newcommand*{\si@ifdefinable}[1]{%
-  \expandafter\expandafter\expandafter\@ifundefined%
-    \expandafter\expandafter\expandafter%
-      {\expandafter\@gobble\string#1}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@addtolist}
-%\darg{macro}
-%\darg{items}
-% It is quite useful to be able to add to a comma-separated list of
-% expandable items.
-%    \begin{macrocode}
-\newcommand*{\si@addtolist}[2]{%
-  \ifx\@empty#1\@empty
-    \edef#1{#2}%
-  \else
-    \edef#1{#1,#2}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@addtocsname}
-%\darg{csname}
-%\darg{tokens}
-% A second item to add to a command sequence.
-%    \begin{macrocode}
-\newcommand*{\si@addtocsname}[2]{%
-  \@ifundefined{#1}
-    {\expandafter\gdef\csname #1\endcsname{#2}}
-    {\si@temptoks\expandafter\expandafter\expandafter{%
-       \csname #1\endcsname#2}%
-     \expandafter\xdef\csname #1\endcsname{\the\si@temptoks}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ifmtarg}
-%\begin{macro}{\si@xifmtarg}
-%\begin{macro}{\si@ifnotmtarg}
-% To keep down dependance on other packages, the very short code
-% block from \pkg{ifmtarg} is copied here with an internal name.
-%    \begin{macrocode}
-\begingroup
-  \catcode`\Q=3
-  \long\gdef\si@ifmtarg#1{%
-    \si@xifmtarg#1QQ\@secondoftwo\@firstoftwo\@nil}
-  \long\gdef\si@xifmtarg#1#2Q#3#4#5\@nil{#4}
-  \long\gdef\si@ifnotmtarg#1{%
-    \si@xifmtarg#1QQ\@firstofone\@gobble\@nil}
-\endgroup
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@newrobustcmd}
-%\begin{macro}{\si@newcommand}
-%\begin{macro}{\si@newcmd}
-%\begin{macro}{\si@xargdef}
-%\darg{macro}
-%\doarg{num-args}
-%\doarg{default}
-%\darg{def}
-% Some more copying, this time from \pkg{etoolbox}.  Various macros
-% need to be \emph{really} robust.  This is achieved using the \eTeX\
-% \cs{protected} primitive in various places.  However, it would be
-% nice to have a \cs{protected} version of \cs{newcommand}.
-% \pkg{etoolbox} has code for that, but to avoid needing to load it,
-% the necessary stuff is copied here.  The only changes form the
-% original are names, and the use of \cs{newcommand*} for the
-% \cs{si@newcommand} macro.
-%    \begin{macrocode}
-\@ifpackageloaded{etoolbox}
-  {\let\si@newrobustcmd\newrobustcmd}
-  {\protected\def\si@newrobustcmd{%
-     \@ifstar
-       {\let\l@ngrel@x\protected\si@newcommand}
-       {\def\l@ngrel@x{\protected\long}\si@newcommand}}
-   \newcommand*{\si@newcommand}[1]{\@testopt{\si@newcmd#1}0}
-   \def\si@newcmd#1[#2]{%
-     \@ifnextchar[%]
-       {\si@xargdef#1[#2]}
-       {\@argdef#1[#2]}}
-   \long\def\si@xargdef#1[#2][#3]#4{%
-     \@ifdefinable#1{%
-       \expandafter\protected
-       \expandafter\def
-       \expandafter#1%
-       \expandafter{%
-         \expandafter\@testopt
-         \csname\string#1\endcsname{#3}}%
-       \expandafter\@yargdef
-       \csname\string#1\endcsname\tw@{#2}{#4}}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%
-%\subsection{Logging}
-%\begin{macro}{\ifsi@debug}
-%\begin{macro}{\ifsi@logmin}
-%\begin{macro}{\ifsi@lognone}
-% To control logging, some new switches are declared.
-%    \begin{macrocode}
-\newif\ifsi@debug
-\newif\ifsi@logmin
-\newif\ifsi@lognone
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@log@err}
-%\darg{error}
-%\darg{explanation}
-% Some handy re-usable macros are defined here.  These all take names
-% beginning  These pop up in various places.  First errors are
-% handled.
-%    \begin{macrocode}
-\newcommand*{\si@log@err}[2]{%
-  \ifsi@lognone\else
-    \ifsi@logmin
-      \PackageWarning{siunitx}{#1}%
-    \else
-      \PackageError{siunitx}{#1}{#2}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@log@warn}
-%\begin{macro}{\si@log@inf}
-%\darg{text}
-% Then warnings and information.
-%    \begin{macrocode}
-\newcommand*{\si@log@warn}[1]{%
-  \ifsi@lognone\else
-    \ifsi@logmin\else
-      \PackageWarning{siunitx}{#1}%
-    \fi
-  \fi}
-\newcommand*{\si@log@inf}[1]{%
-  \ifsi@lognone\else
-    \ifsi@logmin\else
-      \PackageInfo{siunitx}{#1}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@log@debug}
-%\darg{debug-info}
-% The debug macro only gives output if the appropriate package option
-% is set.
-%    \begin{macrocode}
-\newcommand*{\si@log@debug}[1]{%
-  \ifsi@lognone\else
-    \ifsi@debug
-      \PackageInfo{siunitx}{#1}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%
-%\subsection{String comparison}
-%\begin{macro}{\si@str@ifchrstr}
-%\begin{macro}{\si@str@chrstr}
-%\darg{char}
-%\darg{string}
-% At various points, the package needs to compare two strings, to
-% find if one occurs in the other.  The first test is if a single
-% character is part of a second string; this is used, for example, to
-% check that a character is valid as input.  The first argument is
-% not expanded further, but the second is two allow division into
-% individual units.
-%    \begin{macrocode}
-\newcommand*{\si@str@ifchrstr}[2]{%
-  \begingroup
-    \si@switchfalse
-    \renewcommand*{\si@tempa}{#1}%
-    \protected@edef\si@tempb{#2}%
-    \expandafter\si@str@chrstr\si@tempb\@empty\@empty\@empty
-    \ifsi@switch
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@str@chrstr#1#2\@empty{%
-  \renewcommand*{\si@tempc}{#1}%
-  \ifx\si@tempa\si@tempc
-    \expandafter\si@switchtrue
-  \else
-    \ifx\@empty#2\@empty\else
-      \si@str@chrstr#2\@empty\@empty
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@str@ifonlychrs}
-%\begin{macro}{\si@str@onlychrs}
-%\darg{string}
-%\darg{chars}
-% The second test builds on the first.  Here, a check is made to see
-% if the first string is made up only of characters from the second
-% string.  In this case, the first string is expanded before
-% testing.  The second string will be expanded by the internal
-% character by character test.
-%    \begin{macrocode}
-\newcommand*{\si@str@ifonlychrs}[2]{%
-  \begingroup
-    \si@switchtrue
-    \protected@edef\si@tempa{#1}%
-    \renewcommand*{\si@tempb}{#2}%
-    \expandafter\si@str@onlychrs\si@tempa\@empty\@empty\@empty
-    \ifsi@switch
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@str@onlychrs#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@tempb}
-    {}{\si@switchfalse}%
-  \ifx\@empty#2\@empty\else
-    \si@str@onlychrs#2\@empty\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%
-%\subsection{Option handling}
-%\begin{macro}{\sisetup}
-%\darg{options}
-% To allow modification of options at run time, a setup macro is
-% provided.
+%\subsection{Preliminaries}
+%
+% The usual preliminaries.  
 %    \begin{macrocode}
-\newcommand*{\sisetup}{\setkeys[si]{key}}
+\ProvidesExplPackage {siunitx} {2010/05/23} {2.0}
+  {A comprehensive (SI) units package}
 %    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@key}
-%\darg{keyname}
-%\darg{code}
-% To aid maintenance, some shortcuts are defined for generating keys.
-% These also allow the debugging messages to be added automatically
-% to every key.  First of all the basic key definition.
+%    
+%\begin{macro}{\_siunitx_load_check:}
+% There are also a number of packages that are incompatible with
+% \pkg{siunitx}. These are all checked for next.  Some of the 
+% incompatible packages will not raise an error if loaded after 
+% \pkg{siunitx}.  So a test is made at the beginning of the 
+% document as well. The message for this may be needed immediately, so
+% it is created here not with the other messages.
 %    \begin{macrocode}
-\newcommand*{\si@opt@key}[2]{%
-  \define@key[si]{key}{#1}
-  {#2\si@log@debug{Option #1 set to ##1}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@cmdkey}
-%\doarg{default}
-%\darg{keyname}
-%\darg{function}
-% For a single command key, a function must be specified.
-%    \begin{macrocode}
-\newcommand*{\si@opt@cmdkey}[3][]{%
-  \define@cmdkey[si]{key}[si@]{#2}[#1]{#3}}
+\msg_set:nnnn { siunitx } { incompatible-package } 
+  { Package~'#1'~incompatible. }
+  { The~#1~package~and~siunitx~are~incompatible. }
+\cs_set_protected_nopar:Npn \_siunitx_load_check:n #1 {
+  \group_begin:
+    \@ifpackageloaded {#1} 
+      { \msg_error:nnx { siunitx } { incompatible-package } {#1} } 
+      { }
+  \group_end:
+}
+\clist_map_function:nN 
+  { SIunits , sistyle , siunits , SIstyle , unitsdef , fancyunits }
+  \_siunitx_load_check:n
+\AtBeginDocument {
+  \clist_map_function:nN { SIunits , sistyle , siunits , SIstyle }
+    \_siunitx_load_check:n
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@opt@cmdkeys}
-%\doarg{default}
-%\darg{keyname}
-% Whereas multiple definitions do not take a function.
+%
+% Now load the support packages.
 %    \begin{macrocode}
-\newcommand*{\si@opt@cmdkeys}[2][]{%
-  \define@cmdkeys[si]{key}[si@]{#2}[#1]}
+\RequirePackage{ amstext , array , l3keys2e }
 %    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@boolkey}
-%\doarg{function}
-%\darg{keyname}
-% Keys which only take switch values; anything other than \opt{true}
-% or \opt{false} will generate a warning from \pkg{xkeyval}.
+%    
+%\begin{macro}{\_siunitx_tmp:w}
+%\begin{macro}{\_l_siunitx_tmp_bool}
+%\begin{macro}{\_l_siunitx_tmp_box}
+%\begin{macro}{\_l_siunitx_tmp_int}
+%\begin{macro}{\_l_siunitx_tmpa_tl}
+%\begin{macro}{\_l_siunitx_tmpb_tl}
+% Scratch items.
 %    \begin{macrocode}
-\newcommand*{\si@opt@boolkey}[2][]{%
-  \define@boolkey[si]{key}[si@]{#2}[true]
-  {#1\si@log@debug{Option #2 set to ##1}}}
+\cs_set:Npn \_siunitx_tmp:w { }
+\bool_new:N \_l_siunitx_tmp_bool
+\box_new:N \_l_siunitx_tmp_box
+\int_new:N \_l_siunitx_tmp_int
+\tl_new:N \_l_siunitx_tmpa_tl
+\tl_new:N \_l_siunitx_tmpb_tl
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@opt@choicekey}
-%\doarg{default}
-%\darg{keyname}
-%\darg{choices}
-%\darg{function}
-% A ``fill in the blanks'' choice key.  In all cases, \cs{si@tempa}
-% is used to hold the value given to the key, so that \cs{ifx}
-% testing can occur.
-%    \begin{macrocode}
-\newcommand*{\si@opt@choicekey}[4][]{%
-  \define@choicekey*+[si]{key}{#2}[\si@tempa]{#3}[#1]
-    {#4\si@log@debug{Option #2 set to ##1}}
-    {\si@log@warn{Unknown value `##1' for option #2}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@xchoicekey}
-%\darg{keyname}
-%\darg{choices}
-%\darg{initial-value}
-% Several of the package options can take either a choice from a list
-% of known options, or a value to be interpreted literally.  To aid
-% maintenance, the necessary code can be set up here.  These keys all
-% define a new macro, which must exist.  The \cs{si@opt@xchoicekey}
-% macro therefore ensures that this is defined, as well as setting up
-% the \pkg{xkeyval} key.
-%    \begin{macrocode}
-\newcommand*{\si@opt@xchoicekey}[3]{%
-  \define@choicekey*+[si]{key}{#1}[\si@tempa]{#2}[#1]
-%    \end{macrocode}
-% This code will execute if the option is on the list.  There will be
-% a ``fixed'' macro with a matching name, which is used for this.
-%    \begin{macrocode}
-    {\si@log@debug{Option #1 set to ##1}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-      \csname si@#1\endcsname}{\@nameuse{si@fix@##1}}}
-%    \end{macrocode}
-% The user has given something that is not on the list as an
-% argument.  It is used literally.
-%    \begin{macrocode}
-    {\si@log@debug{Option #1 set to ##1}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-      \csname si@#1\endcsname}{##1}}
-%    \end{macrocode}
-% Finally, the initial value of the macro is set up.
-%    \begin{macrocode}
-  \expandafter\newcommand\expandafter*\expandafter{%
-    \csname si@#1\endcsname}%
-    {\@nameuse{si@fix@#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@compatkey}
-%\darg{package}
-%\darg{keyname}
-% An all-in-one definition for a back-compatibility key.  These
-% should only be used at load time, so are automatically disabled
-% once the package is loaded.  Emulation is also automatically turned
-% on.
-%    \begin{macrocode}
-\newcommand*{\si@opt@compatkey}[2]{%
-  \define@boolkey[si]{key}[si@old@]{#2}[true]
-  {\si@log@debug{Emulating #1 package option\MessageBreak #2}%
-   \sisetup{emulate=#1}%
-   \si@log@debug{Option #2 set to ##1}}
-   \AtEndOfPackage{\si@opt@disablekey{#2}
-     {Compatibility option #2 only\MessageBreak
-        available when loading siunitx package}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@opt@disablekey}
-%\darg{keyname}
-%\darg{text}
-% The ability to disable a key with a meaningful message is a must;
-% the warning will come from \currpkg, and not from \pkg{xkeyval}.
-%    \begin{macrocode}
-\newcommand*{\si@opt@disablekey}[2]{%
-  \key@ifundefined[si]{key}{#1}
-    {}
-    {\si@log@debug{Disabling key #1}%
-     \si@opt@key{#1}{\si@log@warn{#2}}}}
-%    \end{macrocode}
-%\end{macro}
-%
-% The \pkg{xkeyval} package option for logging is declared. This is
-% then processed to set the switches correctly.
-%    \begin{macrocode}
-\si@opt@choicekey[normal]{log}{debug,verbose,normal,errors,none}
-%    \end{macrocode}
-% A series of comparisons are made to assign the logging mode.  The
-% \opt{normal} option is not tested, as executing the option sets the
-% switches appropriately.
-%    \begin{macrocode}
-  {\si@debugfalse
-   \si@logminfalse
-   \si@lognonefalse
-   \renewcommand*{\si@tempb}{none}%
-   \ifx\si@tempa\si@tempb
-     \si@lognonetrue
-   \fi
-   \renewcommand*{\si@tempb}{minimal}%
-   \ifx\si@tempa\si@tempb
-     \si@logmintrue
-   \fi
-   \renewcommand*{\si@tempb}{debug}%
-   \ifx\si@tempa\si@tempb
-     \si@debugtrue
-   \fi
-   \renewcommand*{\si@tempb}{verbose}%
-   \ifx\si@tempa\si@tempb
-     \si@debugtrue
-   \fi}
-%    \end{macrocode}
-% A quick method to set \opt{log=debug}.
-%    \begin{macrocode}
-\si@opt@boolkey{debug}
-%    \end{macrocode}
-%\begin{macro}{\ifsi@strict}
-% It would be useful to be able to disable some keys, when strict
-% interpretation of the rules is desired.  This is a load-time
-% option, and has to disable various options.
-%    \begin{macrocode}
-\si@opt@boolkey[%
-  \ifsi@strict
-    \sisetup{
-      obeymode=false,
-      obeybold=false,
-      obeyitalic=false,
-      mode=maths,
-      repeatunits=true,
-      trapambigerr=true,
-      trapambigfrac=true,
-      trapambigrange=true}
-    \@for\si@tempa:=obeyall,obeymode,obeyitalic,mode,unitmode,%
-      valuemode,textmode,obeybold,repeatunits,trapambigerr,%
-      trapambigfrac,trapambigrange\do{%
-      \begingroup
-        \edef\si@tempb{\endgroup
-          \noexpand\si@opt@disablekey{\si@tempa}
-          {Option `\si@tempa' forbidden in strict mode}}%
-      \si@tempb}
-  \fi]{strict}
-\AtEndOfPackage{
-  \si@opt@disablekey{strict}
-    {Option `strict' only available when\MessageBreak
-     loading package}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@emulate}
-% The \opt{emulate} option is used for back-compatibility mode; the
-% option is only valid when loading \currpkg.
-%    \begin{macrocode}
-\newcommand*{\si@emulate}{}
-\si@opt@key{emulate}{\si@addtolist{\si@emulate}{#1}}
-\AtEndOfPackage{
-  \si@opt@disablekey{emulate}
-    {Option `emulate' only available when\MessageBreak
-     loading package}}
-%    \end{macrocode}
-%\end{macro}
-%\changes{2009/03/23}{v1.2g}{Added missing \texttt{space} option
-%  for various separators}
-%\begin{macro}{\si@unitsep}
-%\begin{macro}{\si@unitspace}
-%\begin{macro}{\si@errspace}
-%\begin{macro}{\si@valuesep}
-% The two \opt{\dots sep} options control the size of spaces between
-% the number and the unit (\cs{si@valuesep}), and that used to
-% represent a product (\cs{si@unitsep}).  Known values here are
-% \opt{thin}, \opt{med}, \opt{medium}, \opt{thick}, \opt{cdot},
-% \opt{tightcdot}\footnote{Both \cs{cdot}-based options only valid
-% for \opt{unitsep}.} and \opt{none};\footnote{Only valid for
-% \opt{valuesep}.} other entries will be treated as custom spaces.
-%    \begin{macrocode}
-\si@opt@xchoicekey{unitsep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-    times,tighttimes,cdot,tightcdot}{thin}
-\si@opt@xchoicekey{unitspace}{space,thin,med,medium,thick,
-  none}{thin}
-\si@opt@xchoicekey{errspace}{space,thin,med,medium,thick,
-  none}{none}
-\si@opt@xchoicekey{valuesep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-    times,tighttimes,cdot,tightcdot}{thin}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@digitsep}
-% Separation of digits in large numbers is controlled by the
-% \opt{digitsep} option.  As with the other \opt{sep} values, this
-% one has a choice of possible values.  The list is quite long, so
-% that a range of options are handled automatically.  Notice that
-% \opt{digitsep=none} will be used for no separation at all.
-%    \begin{macrocode}
-\si@opt@xchoicekey{digitsep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-    times,tighttimes,cdot,tightcdot}{thin}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@decimalsymbol}
-% The symbol used for the decimal position is varied here.  There are
-% only two real options, but options are given for the name of a full
-% stop.
-%    \begin{macrocode}
-\si@opt@xchoicekey{decimalsymbol}{comma,stop,fullstop,period,
-  cdot,tightcdot}{fullstop}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@anglesep}
-% The separator between degrees and minutes, and between minutes and
-% seconds, when using \cs{ang}.
-%    \begin{macrocode}
-\si@opt@xchoicekey{anglesep}
-    {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-      times,tighttimes,cdot,tightcdot}{none}
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@obeymode}
-% The first test for the font control is whether to respect the
-% surrounding maths or text mode.
-%    \begin{macrocode}
-\si@opt@boolkey{obeymode}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@numtextmode}
-%\begin{macro}{\ifsi@unittextmode}
-% The output of the package can be typeset using either text or maths
-% mode fonts. Two switches are needed, for numbers and units.
-%    \begin{macrocode}
-\newif\ifsi@numtextmode
-\newif\ifsi@unittextmode
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-% The \opt{textmode} option has to set both flags.
-%    \begin{macrocode}
-\si@opt@choicekey[true]{textmode}{true,false}
-  {\si@numtextmodefalse
-   \si@unittextmodefalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-     \si@unittextmodetrue
-   \fi}
-%    \end{macrocode}
-% The \opt{mode} option applies to numbers and units.
-%    \begin{macrocode}
-\si@opt@choicekey{mode}{math,maths,text}
-  {\si@numtextmodefalse
-   \si@unittextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-     \si@unittextmodetrue
-   \fi}
-%    \end{macrocode}
-% Now the two options for numbers or units alone.
-%    \begin{macrocode}
-\si@opt@choicekey{valuemode}{math,maths,text}
-  {\si@numtextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-   \fi}
-\si@opt@choicekey{unitmode}{math,maths,text}
-  {\si@unittextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@unittextmodetrue
-   \fi}
-%    \end{macrocode}
-%\begin{macro}{\ifsi@obeyfamily}
-% The package can work to match the font family (serif, sans serif,
-% typewriter) of the surrounding text.  This is controlled by a
-% Boolean option.
-%    \begin{macrocode}
-\si@opt@boolkey{obeyfamily}
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@obeybold}
-% The package can attempt to respect bold, or may ignore it.
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_error_bool}
+%\begin{macro}{\_siunitx_error:nxx}
+%\begin{macro}{\_siunitx_error:nx}
+%\begin{macro}{\_siunitx_error:n}
+%\begin{macro}{\_siunitx_error:nV}
+% General-purpose functions for throwing errors.
 %    \begin{macrocode}
-\si@opt@boolkey{obeybold}
+\bool_new:N \_l_siunitx_error_bool
+\cs_set_protected:Npn \_siunitx_error:nxx #1#2#3 {
+  \bool_set_true:N \_l_siunitx_error_bool
+  \msg_error:nnxx { siunitx } {#1} {#2} {#3}
+}
+\cs_set_protected:Npn \_siunitx_error:nx #1#2 {
+  \_siunitx_error:nxx {#1} {#2} { }
+}
+\cs_set_protected:Npn \_siunitx_error:n #1 {
+  \_siunitx_error:nxx {#1} { } { }
+}
+\cs_generate_variant:Nn \_siunitx_error:nx { nV }
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@inlinebtext}
-% For inline maths, two options for checking what is bold are
-% available, the maths environment (\ie \cs{boldmath}) and the
-% surrounding text (\cs{textbf} or \cs{bffamily}).
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%    
+% Some of the \texttt{TS1} encoding is needed to provide symbols in 
+% text mode. If the user has not loaded the encoding themselves, it is
+% done here.
 %    \begin{macrocode}
-\newif\ifsi@inlinebtext
-\si@opt@choicekey{inlinebold}{text,maths,math}
-  {\si@inlinebtextfalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@inlinebtexttrue
-   \fi}
+\AtBeginDocument { 
+  \cs_if_free:cT { T@TS1 } 
+    {
+      \DeclareFontEncoding { TS1 } { } { } 
+      \DeclareFontSubstitution { TS1 } { cmr } { m } { n } 
+    }
+}
 %    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@obeyitalic}
-% Italic is slightly different to bold, as there is no convenient
-% switch for maths.  Thus a choice key is used, with the appropriate
-% check.
+%
+%\begin{macro}{\_c_siunitx_minus_tl}
+% To allow the correct symbol to appear in text mode: this is the same
+% as \cs{textminus} from \pkg{textcomp}.
 %    \begin{macrocode}
-\si@opt@boolkey{obeyitalic}
+\DeclareTextSymbolDefault \_c_siunitx_minus_tl { TS1 }
+\DeclareTextSymbol \_c_siunitx_minus_tl { TS1 } { 61 }
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@detectdisplay}
-% For handling display mathematics, a setting is needed for whether to
-% treat it differently from other maths.
+%
+%\begin{macro}{\_c_siunitx_mu_tl}
+% The lack of an upright mu has to be sorted out.
 %    \begin{macrocode}
-\si@opt@boolkey{detectdisplay}
+\DeclareTextSymbol \_c_siunitx_mu_tl { TS1 } { 181 }
+\DeclareTextSymbolDefault \_c_siunitx_mu_tl { TS1 }
 %    \end{macrocode}
 %\end{macro}
-% The option to obey all font switching commands is Boolean-like but
-% needs alternative setup.
+%
+% Some package redefine \cs{Omega} to be slanted and move the original
+% symbol to \cs{upOmega}. This is handled here.
 %    \begin{macrocode}
-\si@opt@choicekey[true]{obeyall}{true,false}
-  {\si@obeyboldfalse
-   \si@obeyitalicfalse
-   \si@obeymodefalse
-   \si@obeyfamilyfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@obeyboldtrue
-     \si@obeyitalictrue
-     \si@obeymodetrue
-     \si@obeyfamilytrue
-   \fi}
+\tl_new:N \_c_siunitx_omega_tl
+\tl_set:Nn \_c_siunitx_omega_tl { \Omega }
+\AtBeginDocument {
+  \cs_if_exist:NT \upOmega 
+    { \tl_set:Nn \_c_siunitx_omega_tl { \upOmega } }
+}
 %    \end{macrocode}
-%\begin{macro}{\si@valuemathsrm}
-%\begin{macro}{\si@valuemathssf}
-%\begin{macro}{\si@valuemathstt}
-%\begin{macro}{\si@unitmathsrm}
-%\begin{macro}{\si@unitmathssf}
-%\begin{macro}{\si@unitmathstt}
-% The fonts used by the package default to the obvious \LaTeX\ ones;
-% however, this needs to be exposed to user modification.  First the
-% maths mode fonts are sorted out.
+%
+%\begin{macro}{\_siunitx_tl_put_left_math:Nn}
+%\begin{macro}{\_siunitx_tl_put_left_math:NV}
+%\begin{macro}{\_siunitx_tl_put_left_math:cV}
+%\begin{macro}{\_siunitx_tl_put_right_math:Nn}
+%\begin{macro}{\_siunitx_tl_put_right_math:NV}
+%\begin{macro}{\_siunitx_tl_put_right_math:cV}
+% To add stuff in math mode.
 %    \begin{macrocode}
-\si@opt@cmdkeys{valuemathsrm,valuemathssf,valuemathstt}
-\si@opt@cmdkeys{unitmathsrm,unitmathssf,unitmathstt}
+\cs_set_protected:Npn \_siunitx_tl_put_left_math:Nn #1#2 {
+  \tl_put_left:Nn #1 { \_siunitx_ensuremath:n {#2} }
+}
+\cs_generate_variant:Nn \_siunitx_tl_put_left_math:Nn { NV }
+\cs_generate_variant:Nn \_siunitx_tl_put_left_math:Nn { cV }
+\cs_set_protected:Npn \_siunitx_tl_put_right_math:Nn #1#2 {
+  \tl_put_right:Nn #1 { \_siunitx_ensuremath:n {#2} }
+}
+\cs_generate_variant:Nn \_siunitx_tl_put_right_math:Nn { NV }
+\cs_generate_variant:Nn \_siunitx_tl_put_right_math:Nn { cV }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -4087,1054 +3803,1094 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-% To make life easier for the user, US spellings are provided for the
-% maths keys.
+%
+% Unknown options should raise an \pkg{siunitx}-specific error message.
 %    \begin{macrocode}
-\si@opt@key{valuemathrm}{\sisetup{valuemathsrm=#1}}
-\si@opt@key{valuemathsf}{\sisetup{valuemathssf=#1}}
-\si@opt@key{valuemathtt}{\sisetup{valuemathstt=#1}}
-\si@opt@key{unitmathrm}{\sisetup{unitmathsrm=#1}}
-\si@opt@key{unitmathsf}{\sisetup{unitmathssf=#1}}
-\si@opt@key{unitmathtt}{\sisetup{unitmathstt=#1}}
+\keys_define:nn { siunitx } {
+  unknown .code:n = 
+    { 
+      \msg_error:nnx { siunitx } { unknown-option } 
+        { \exp_not:V \l_keys_key_tl } 
+    }
+}
 %    \end{macrocode}
-% The combined options are given, for setting numbers and units
-% at the same time.
+%
+%\begin{macro}{\_l_siunitx_option_deactivate_clist}
+%\begin{macro}{\_siunitx_option_deactivate:n}
+%\begin{macro}[aux]{\_siunitx_option_deactivate_aux:n}
+% Some options need to be deactivated at the start of the document.
 %    \begin{macrocode}
-\si@opt@key{mathsrm}{\sisetup{valuemathsrm=#1,unitmathsrm=#1}}
-\si@opt@key{mathssf}{\sisetup{valuemathssf=#1,unitmathssf=#1}}
-\si@opt@key{mathstt}{\sisetup{valuemathstt=#1,unitmathstt=#1}}
-\si@opt@key{mathrm}{\sisetup{valuemathsrm=#1,unitmathsrm=#1}}
-\si@opt@key{mathsf}{\sisetup{valuemathssf=#1,unitmathssf=#1}}
-\si@opt@key{mathtt}{\sisetup{valuemathstt=#1,unitmathstt=#1}}
+\clist_new:N \_l_siunitx_option_deactivate_clist
+\cs_set_protected_nopar:Npn \_siunitx_option_deactivate:n #1 {
+  \clist_put_right:Nn \_l_siunitx_option_deactivate_clist {#1}
+}
+\cs_set_protected_nopar:Npn \_siunitx_option_deactivate_aux:n #1 {
+  \keys_define:nn { siunitx } 
+    {
+      #1 .code:n = 
+        { \msg_warning:nnx { siunitx } { option-preamble-only } {#1} }
+    }
+}
+\AtBeginDocument {
+  \clist_map_function:NN \_l_siunitx_option_deactivate_clist
+    \_siunitx_option_deactivate_aux:n
+}
 %    \end{macrocode}
-%\begin{macro}{\si@valuetextrm}
-%\begin{macro}{\si@valuetextsf}
-%\begin{macro}{\si@valuetexttt}
-%\begin{macro}{\si@unittextrm}
-%\begin{macro}{\si@unittextsf}
-%\begin{macro}{\si@unittexttt}
-% The same thing for text mode fonts.  Once again the default values
-% are pretty obvious.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\prop_del:cn}
+%\begin{macro}{\prop_put:cnV}
+%\begin{macro}{\tl_replace_all_in:NnV}
+% Variants needed which are not in \pkg{expl3}.
 %    \begin{macrocode}
-\si@opt@cmdkeys{valuetextrm,valuetextsf,valuetexttt}
-\si@opt@cmdkeys{unittextrm,unittextsf,unittexttt}
-\si@opt@key{textrm}{\sisetup{unittextrm=#1,valuetextrm=#1}}
-\si@opt@key{textsf}{\sisetup{unittextsf=#1,valuetextsf=#1}}
-\si@opt@key{texttt}{\sisetup{unittexttt=#1,valuetexttt=#1}}
+\cs_generate_variant:Nn \prop_del:Nn { c }
+\cs_generate_variant:Nn \prop_put:Nnn { cnV }
+\cs_generate_variant:Nn \tl_replace_all_in:Nnn { NnV }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_cs_if_tl:NT}
+%\begin{macro}{\_siunitx_cs_if_tl:NTF}
+%\begin{macro}[aux]{\_siunitx_cs_if_tl_aux:w}
+%\begin{macro}{\_siunitx_cs_if_macro:NT}
+% This is basically a re-hash of stuff from \pkg{expl3}, but to test for
+% short macros only. The second test (with the \cs{cs_to_str:N} part)
+% is checking for LaTeX2e robust commands.
+%    \begin{macrocode}
+\group_begin:
+\tl_map_inline:nn { \M \A \C \R \O } 
+  { \char_make_other:n { `#1 } }
+\tl_map_inline:nn { \F \N \T }
+  { \char_set_lccode:nn { `#1 } { `#1 } } 
+\tl_to_lowercase:n {
+  \group_end:
+  \prg_new_conditional:Nnn \_siunitx_cs_if_tl:N { T , TF } 
+    {
+      \exp_after:wN \_siunitx_cs_if_tl_aux:w
+        \token_to_meaning:N #1 MACRO \q_nil
+          { 
+            \cs_if_exist:cTF { \cs_to_str:N #1 ~ }
+              { \prg_return_false: }
+              { \prg_return_true: }
+          } 
+          { \prg_return_false: }
+    }
+  \cs_set_nopar:Npn \_siunitx_cs_if_tl_aux:w #1 MACRO #2 \q_nil 
+    { \tl_if_empty:nTF {#1} }
+  \prg_new_conditional:Nnn \_siunitx_cs_if_macro:N { T } 
+    {
+      \exp_after:wN \_siunitx_cs_if_tl_aux:w
+        \token_to_meaning:N #1 MACRO \q_nil
+          { \prg_return_true: }
+          { \prg_return_false: }
+    }
+}
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\changes{v1.1}{2008/09/22}{Added \opt{numdiv} option}
-%\begin{macro}{\si@numdigits}
-%\begin{macro}{\si@numdiv}
-%\begin{macro}{\si@numdecimal}
-%\begin{macro}{\si@numexp}
-%\begin{macro}{\si@numprod}
-%\begin{macro}{\si@numgobble}
-%\begin{macro}{\si@numsign}
-%\begin{macro}{\si@numcloseerr}
-%\begin{macro}{\si@numopenerr}
-%\begin{macro}{\si@numaddn}
-% The list of possible valid characters for parsing numbers is set
-% up.  This is similar to \numprint, but with the \opt{extra} class,
-% and with characters ignored with no output renamed as \opt{gobble}.
+%
+%\begin{macro}{\_siunitx_ensuremath:n}
+% A copy is made of \cs{ensuremath}: if \pkg{tex4ht} is in use, it
+% is possible to deactivate this to give nicer looking conversion to
+% other formats.
 %    \begin{macrocode}
-\si@opt@cmdkeys{numdigits,numdecimal,numexp,numgobble,numsign,%
-  numcloseerr,numopenerr,numaddn,numprod,numdiv}
+\cs_set_eq:NN \_siunitx_ensuremath:n \ensuremath
+\AtBeginDocument {
+  \@ifpackageloaded { tex4ht }
+    { 
+      \cs_set_eq:NN \_siunitx_ensuremath:n \use:n 
+      \keys_set:nn { siunitx } { mode = text }
+    }
+    { }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\subsection{Font detection}
+%
+% A number of controls and tests are needed to control the font used
+% for output.  The detection routines set up various functions which can
+% then be used inside the \cs{text} macro from the \pkg{amstext}
+% package.  By carrying out the changes outside math mode, bold can
+% reliably be applied to math output.
+% 
+%\begin{macro}{\_c_siunitx_mathsf_int}
+%\begin{macro}{\_c_siunitx_mathtt_int}
+%\begin{macro}{\_siunitx_set_math_fam:n}
+% The detection routine needs some basic data about the sans serif and
+% monospaced fonts in use.  This is collected up at the start of the 
+% document. The families used can change between here and the start of 
+% the document. This is run as a hook onto \cs{document}, rather than
+% using \cs{AtBeginDocument} as it has to come after anything that
+% \pkg{fontspec} does (nasty errors arise otherwise). 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_set_math_fam:n #1 {
+  \int_new:c { _c_siunitx_math #1 _int }
+  \group_begin:
+    \hbox_set:Nn \_l_siunitx_tmp_box 
+      {
+        \ensuremath 
+          {
+            \use:c { math #1 } 
+              {
+                \int_gset:cn { _c_siunitx_math #1 _int } { \fam }  
+              }
+          }
+      }  
+  \group_end:
+}
+\tl_put_right:Nn \document {
+  \_siunitx_set_math_fam:n { sf }
+  \_siunitx_set_math_fam:n { tt }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_font_set_text_fam:n}
+%\begin{macro}{\_c_siunitx_textsf_tl}
+%\begin{macro}{\_c_siunitx_texttt_tl}
+% The text families are done in a somewhat different manner: there are 
+% no issues with \cs{AtBeginDocument}, luckily. The need to define 
+% new macros here arises as \cs{sfdefault} and \cs{ttdefault} are 
+% \cs{long}, whereas \cs{f@family} is not.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_set_text_fam:n #1 {
+  \tl_new:c { _c_siunitx_text #1 _tl }
+  \tl_set:cx { _c_siunitx_text #1 _tl } { \use:c { #1 default } }
+}
+\AtBeginDocument {
+  \_siunitx_set_text_fam:n { sf }
+  \_siunitx_set_text_fam:n { tt }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_detect_inline_weight_tl}
+% Used by the keys, but needs to be created here.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_detect_inline_weight_tl
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_detect_display_math_bool}
+%\begin{macro}{\_l_siunitx_detect_family_bool}
+%\begin{macro}{\_l_siunitx_detect_inline_weight_bool}
+%\begin{macro}{\_l_siunitx_detect_italic_bool}
+%\begin{macro}{\_l_siunitx_detect_mode_bool}
+%\begin{macro}{\_l_siunitx_detect_weight_bool}
+% Font detection is all about creating switches, with just a little
+% gloss for \texttt{detect-all} and \texttt{detect-none}.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  detect-all .choice:,
+  detect-all .default:n = true,
+  detect-all / false .meta:n = 
+    {
+      detect-family = false,
+      detect-italic = false,
+      detect-mode   = false,
+      detect-weight = false
+    },
+  detect-all / true .meta:n = 
+    {
+      detect-family = true,
+      detect-italic = true,
+      detect-mode   = true,
+      detect-weight = true
+    },
+  detect-display-math  .bool_set:N = 
+    \_l_siunitx_detect_display_math_bool,
+  detect-family        .bool_set:N = \_l_siunitx_detect_family_bool,
+  detect-inline-weight .choice:,
+  detect-inline-weight .value_required:,
+  detect-inline-weight / 
+    combined           .code:n = 
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { combined } },
+  detect-inline-weight / 
+    math               .code:n     = 
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { math } },
+  detect-inline-weight / 
+    text               .code:n     = 
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { text } },
+  detect-italic        .bool_set:N = \_l_siunitx_detect_italic_bool,
+  detect-mode          .bool_set:N = \_l_siunitx_detect_mode_bool,
+  detect-none          .choice:,
+  detect-none          .default:n = true,
+  detect-none / false .meta:n = 
+    {
+      detect-family = true,
+      detect-italic = true,
+      detect-mode   = true,
+      detect-weight = true
+    },
+  detect-none / true .meta:n = 
+    {
+      detect-family = false,
+      detect-italic = false,
+      detect-mode   = false,
+      detect-weight   = false
+    },
+  detect-weight        .bool_set:N = \_l_siunitx_detect_weight_bool
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@numvalid}
-%\begin{macro}{\si@numextra}
-% The various valid characters are collected together in a single
-% macro for later.  In common with the above macros, this one starts
-% \cs{si@num\ldots}.  The order here is the order the values are
-% tested later on.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_font_set_bool}
+%\begin{macro}{\_l_siunitx_font_math_mode_bool}
+% The internals of the package need a number of switches to track what
+% is happening.
 %    \begin{macrocode}
-\newcommand*{\si@numextra}{%
-  \si@numopenerr\si@numcloseerr\si@numaddn}
-\newcommand*{\si@numvalid}{\si@numgobble\si@numexp\si@numsign
-  \si@numdecimal\si@numdigits\si@numextra\si@numprod\si@numdiv}
+\bool_new:N \_l_siunitx_font_set_bool
+\bool_new:N \_l_siunitx_font_math_mode_bool
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@seperr}
-%\begin{macro}{\ifsi@trapambigerr}
-%\begin{macro}{\si@openerr}
-%\begin{macro}{\si@closeerr}
-% An option to control whether numerical error values are printed with
-% or separate from the number.
+%
+%\begin{macro}{\_l_siunitx_font_family_tl}
+% Also some token storage.
 %    \begin{macrocode}
-\si@opt@boolkey{seperr}
-\si@opt@boolkey{trapambigerr}
-\si@opt@cmdkeys{openerr,closeerr}
+\tl_new:N \_l_siunitx_font_family_tl
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_font_italic:}
+%\begin{macro}{\_siunitx_font_weight:}
+% These could be token lists or functions!
+%    \begin{macrocode}
+\cs_set_nopar:Npn \_siunitx_font_italic: { }
+\cs_set_nopar:Npn \_siunitx_font_weight: { }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@sepfour}
-% With four digits in a number, separating may or may not be desired.
-% Note that this option is the same as one for \numprint.
+%
+%\begin{macro}{\_siunitx_detect_font:}
+% The main font-setting macro is a control point for the other
+% functions.  Nesting font-control should not happen, so the first
+% test is to ensure this is not happening.
 %    \begin{macrocode}
-\si@opt@boolkey{sepfour}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font: {
+  \bool_if:NF \_l_siunitx_font_set_bool 
+    {
+      \_siunitx_detect_font_init:
+      \bool_if:NT \_l_siunitx_detect_weight_bool 
+        { \_siunitx_detect_font_weight: }
+      \bool_if:NT \_l_siunitx_detect_family_bool 
+        { \_siunitx_detect_font_family: }
+      \bool_if:NT \_l_siunitx_detect_italic_bool 
+        { \_siunitx_detect_font_italic: }
+      \bool_if:NT \_l_siunitx_detect_mode_bool 
+        { \_siunitx_detect_font_mode: }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@retainplus}
-% An option to keep an explicit positive sign.
+%
+%\begin{macro}{\_siunitx_detect_font_init:}
+% Set up the basic macros on the assumption nothing happens.
 %    \begin{macrocode}
-\si@opt@boolkey{retainplus}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_init: {
+  \bool_set_true:N \_l_siunitx_font_set_bool
+  \cs_set:Npn \_siunitx_font_weight: 
+    {
+      \unboldmath 
+      \mdseries
+    }
+  \cs_set:Npn \_siunitx_font_italic: { \upshape }
+  \tl_set:Nn \_l_siunitx_font_family_tl { rm }
+  \bool_set_true:N \_l_siunitx_font_math_mode_bool
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@expbase}
-%\begin{macro}{\si@expproduct}
-% The options for exponents are set up.
+%
+%\begin{macro}{\_siunitx_detect_font_weight:}
+% The font weight detection code depends on whether the current text is 
+% math or text, and also the type of math (if appropriate).  For 
+% inline math, there is a choice of what test to apply.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight: {
+  \mode_if_math:TF 
+    {
+      \mode_if_inner:TF 
+        {
+          \use:c 
+            {
+              _siunitx_detect_font_weight_ 
+              \_l_siunitx_detect_inline_weight_tl
+              :
+            }
+        }
+        {
+          \bool_if:NTF \_l_siunitx_detect_display_math_bool 
+            { \_siunitx_detect_font_weight_math: }
+            { \_siunitx_detect_font_weight_text: }
+        }
+    }
+    { \_siunitx_detect_font_weight_text: }
+}
+%    \end{macrocode}
+%\end{macro}
+%\begin{macro}{\_siunitx_detect_font_weight_combined:}
+%\begin{macro}{\_siunitx_detect_font_weight_math:}
+%\begin{macro}{\_siunitx_detect_font_weight_text:}
+% The tests for font weight depend on whether the module is testing 
+% text or math content.
 %    \begin{macrocode}
-\si@opt@xchoicekey{expproduct}{times,tighttimes,
-  cdot,tightcdot}{times}
-\si@opt@xchoicekey{expbase}{ten}{ten}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_combined: {
+  \_siunitx_detect_font_weight_math:
+  \_siunitx_detect_font_weight_text:
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_math: {
+  \tl_if_eq:nVT { bold } \math@version 
+    {
+      \cs_set:Npn \_siunitx_font_weight: 
+        {
+          \boldmath
+          \bfseries
+        }
+    }
+  \tl_if_eq:nVT { light } \math@version 
+    {
+      \cs_set:Npn \_siunitx_font_weight: 
+        { \lseries }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_text: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl { \exp_args:NV \tl_head_i:n \f@series }
+  \tl_if_eq:nVT { b } \_l_siunitx_tmpa_tl 
+    {
+      \cs_set:Npn \_siunitx_font_weight: 
+        {
+          \boldmath
+          \bfseries
+        }
+    }
+  \tl_if_eq:nVT { l } \_l_siunitx_tmpa_tl  
+    {
+      \cs_set:Npn \_siunitx_font_weight: 
+        { \lseries }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@allowzeroexp}
-% The package normally prevents \num[allowzeroexp]{e0}.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_detect_font_family:}
+% Family detection usually picks up the surrounding text.  However, for
+% display math there are two options, and so a second test may be made.
 %    \begin{macrocode}
-\si@opt@boolkey{allowzeroexp}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family: {
+  \_siunitx_detect_font_family_text:
+  \bool_if:NT \_l_siunitx_detect_display_math_bool 
+    {  
+      \mode_if_math:T 
+        { \mode_if_inner:F { \_siunitx_detect_font_family_math: } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@prefixproduct}
-% The marker for multiplication in prefixes.
-%    \begin{macrocode}
-\si@opt@xchoicekey{prefixproduct}{times,tighttimes,cdot,
-  tightcdot,none}{times}
+%\begin{macro}{\_siunitx_detect_font_family_math:}
+%\begin{macro}{\_siunitx_detect_font_family_text:}
+% The two detections routines check if the current font is sans serif or
+% monospaced.  The method used depends on whether the current math or
+% text font is of interest. The math detection routine re-applies the 
+% default (\texttt{rm}), as the text function is always called and may
+% have changed things.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family_math: {
+  \tl_set:Nn \_l_siunitx_font_family_tl { rm }
+  \intexpr_compare:nNnT 
+    { \int_use:N \fam } = { \int_use:N \_c_siunitx_mathsf_int } 
+    { \tl_set:Nn \_l_siunitx_font_family_tl { sf } }
+  \intexpr_compare:nNnT 
+    { \int_use:N \fam } = { \int_use:N \_c_siunitx_mathtt_int } 
+    { \tl_set:Nn \_l_siunitx_font_family_tl { tt } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family_text: {
+  \tl_if_eq:NNT \f@family \_c_siunitx_textsf_tl 
+    { \tl_set:Nn \_l_siunitx_font_family_tl { sf } }
+  \tl_if_eq:NNT \f@family \_c_siunitx_texttt_tl 
+    { \tl_set:Nn \_l_siunitx_font_family_tl { tt } }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@prefixbase}
-% In the same area, the power for prefixes is variable.  Here, two
-% choices ar needed.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_detect_font_italic:}
+% The italic test uses \cs{f@shape} as a handy indicator.
 %    \begin{macrocode}
-\si@opt@xchoicekey{prefixbase}{ten,two}{ten}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_italic: {
+  \tl_if_eq:nVT { it } \f@shape 
+    { \cs_set_nopar:Npn \_siunitx_font_italic: { \itshape } }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@prefixsymbolic}
-% Unit prefixes can be given as either symbols or numerically.
+%
+%\begin{macro}{\_siunitx_detect_font_mode:}
+% The mode switch works from the fact that math mode output it the
+% standard.
 %    \begin{macrocode}
-\si@opt@boolkey{prefixsymbolic}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_mode: {
+  \mode_if_math:F 
+    { \bool_set_false:N \_l_siunitx_font_math_mode_bool }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@num@padlead}
-%\begin{macro}{\ifsi@num@padtrail}
-% A setting is needed to indicate when to add zeros to decimal
-% numbers, either before the decimal marker (|.1| giving
-% ``\num[padnumber=all]{.1}'') or after (|1.| giving
-% ``\num[padnumber=all]{1.}'').
-%    \begin{macrocode}
-\newif\ifsi@num@padlead
-\newif\ifsi@num@padtrail
-\si@opt@choicekey[all]{padnumber}
-  {leading,lead,trailing,trail,all,both,true,none,false}
-  {\si@num@padleadfalse
-   \si@num@padtrailfalse
-   \renewcommand*{\si@tempb}{leading}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-   \fi
-   \renewcommand*{\si@tempb}{lead}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-   \fi
-   \renewcommand*{\si@tempb}{trailing}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{trail}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@sign}
-%\begin{macro}{\ifsi@num@signmant}
-%\begin{macro}{\ifsi@num@signexp}
-% Some new switches for adding signs to numbers
-%    \begin{macrocode}
-\newif\ifsi@num@signmant
-\newif\ifsi@num@signexp
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% Signs can be added to numbers by default. Two options are needed
-% here; whether to add a sign by default, and what the sign is.
-%    \begin{macrocode}
-\si@opt@xchoicekey{sign}{plus,minus,pm,mp}{plus}
-\si@opt@choicekey[all]{addsign}
-  {mantissa,exponent,mant,exp,all,both,true,none,false}
-%    \end{macrocode}
-%\end{macro}
-% The option is now processed.
-%    \begin{macrocode}
-  {\si@num@signmantfalse
-   \si@num@signexpfalse
-   \renewcommand*{\si@tempb}{mantissa}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-   \fi
-   \renewcommand*{\si@tempb}{mant}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-   \fi
-   \renewcommand*{\si@tempb}{exponent}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{exp}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi}
-%    \end{macrocode}
-%\begin{macro}{\ifsi@tightpm}
-%\begin{macro}{\si@pm}
-% To reduce spacing, it might be necessary to use a ``tight'' $\pm$
-% sign.
-%    \begin{macrocode}
-\si@opt@boolkey{tightpm}
-\newcommand*{\si@pm}{%
-  \ifsi@tightpm
-    \si@fix@tightpm
-  \else
-    \si@fix@pm
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@ang@padsmall}
-%\begin{macro}{\ifsi@ang@padlarge}
-% A switch for determining whether to typeset |\ang{;;1}| as
-% \ang[padangle=both]{;;1} or \ang[padangle=none]{;;1}.  First, two
-% new Boolean switches are needed to indicate padding.
-%    \begin{macrocode}
-\newif\ifsi@ang@padsmall
-\newif\ifsi@ang@padlarge
-\si@opt@choicekey[all]{padangle}
-  {small,large,all,both,true,none,false}
-  {\si@ang@padsmallfalse
-   \si@ang@padlargefalse
-   \renewcommand*{\si@tempb}{small}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-   \fi
-   \renewcommand*{\si@tempb}{large}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@ang@toarc}
-%\begin{macro}{\ifsi@ang@todec}
-% To control whether angles are formatted as decimals or
-% degrees--minutes--seconds, a package option plus two switches are
-% needed.  The later format is referred to as ``\opt{arc}'' most
-% readily.  An option to leave the input unchanged is also provided.
-%    \begin{macrocode}
-\newif\ifsi@ang@toarc
-\newif\ifsi@ang@todec
-\si@opt@choicekey[all]{angformat}
-  {dec,decimal,arc,dms,unchanged,none}
-  {\si@ang@toarcfalse
-   \si@ang@todecfalse
-   \renewcommand*{\si@tempb}{dec}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@todectrue
-   \fi
-   \renewcommand*{\si@tempb}{decimal}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@todectrue
-   \fi
-   \renewcommand*{\si@tempb}{arc}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@toarctrue
-   \fi
-   \renewcommand*{\si@tempb}{dms}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@toarctrue
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@astroang}
-% A slightly odd option to allow the method used by astronomers for
-% angles.
-%    \begin{macrocode}
-\si@opt@boolkey{astroang}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@strictarc}
-% For the \cs{ang} macro, the default is to require two semi-colons
-% in the input for arc angles.  This is controlled here.
-%    \begin{macrocode}
-\si@opt@boolkey{strictarc}
-%    \end{macrocode}
-%\end{macro}
-%\changes{v1.1}{2008/09/03}{Added \opt{tabparseonly} option}
-%\begin{macro}{\ifsi@tab@fixed}
-%\begin{macro}{\ifsi@tabparseonly}
-%\begin{macro}{\si@tabnumalign}
-%\begin{macro}{\si@tab@rfill@S}
-%\begin{macro}{\si@tab@lfill@S}
-% To determine the control of table alignment, two options are
-% provided.  The \opt{tabnumalign} option controls which centring method
-% is used, and the fills used for achieving this.
-%    \begin{macrocode}
-\newif\ifsi@tab@fixed
-\si@opt@boolkey{tabparseonly}
-\si@opt@choicekey{tabnumalign}
-  {centredecimal,centerdecimal,right,left,centre,center}
-  {\si@tab@fixedtrue
-   \def\si@tab@rfill@S{0.5}%
-   \def\si@tab@lfill@S{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@S{0}%
-     \def\si@tab@lfill@S{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@S{1}%
-     \def\si@tab@lfill@S{0}%
-   \fi
-   \renewcommand*{\si@tempb}{centredecimal}%
-   \ifx\si@tempa\si@tempb
-     \expandafter\si@tab@fixedfalse
-   \fi
-   \renewcommand*{\si@tempb}{centerdecimal}%
-   \ifx\si@tempa\si@tempb
-     \expandafter\si@tab@fixedfalse
-   \fi}
-\si@opt@key{tabalign}{\sisetup{tabnumalign=#1,tabtextalign=#1,
-  tabunitalign=#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@tabalignexp}
-% A switch for aligning exponents.
-%    \begin{macrocode}
-\si@opt@boolkey{tabalignexp}
-\si@opt@boolkey[%
-  \si@tabalignexpfalse
-  \ifsi@tabexpalign
-    \expandafter\si@tabalignexptrue
-  \fi
-  ]{tabexpalign}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@mantprecnt}
-%\begin{macro}{\si@tab@mantpostcnt}
-%\begin{macro}{\si@tab@expprecnt}
-%\begin{macro}{\si@tab@exppostcnt}
-%\begin{macro}{\ifsi@tab@mantsign}
-%\begin{macro}{\ifsi@tab@expsign}
-% To process the format information, various internal
-% number-processing macros are used.  First, some
-% storage areas are created.
-%    \begin{macrocode}
-\newcount\si@tab@mantprecnt
-\newcount\si@tab@mantpostcnt
-\newcount\si@tab@expprecnt
-\newcount\si@tab@exppostcnt
-\newif\ifsi@tab@mantsign
-\newif\ifsi@tab@expsign
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% The input is split into a mantissa and exponent, then passed to a
-% re-useable macro for further processing.
-%    \begin{macrocode}
-\si@opt@cmdkey{tabformat}
-  {\si@num@fixpm
-   \renewcommand*{\si@num@arg}{tabformat data}%
-   \renewcommand*{\si@num@exp}{}%
-   \renewcommand*{\si@num@mant}{}%
-   \si@tab@mantsignfalse
-   \si@tab@expsignfalse
-   \si@switchfalse
-   \si@num@sepmantexp{#1}%
-%    \end{macrocode}
-% When checking for a sign, the internal flag for finding but
-% deleting a plus sign is used.
-%    \begin{macrocode}
-   \si@num@sepsign{mant}%
-   \ifx\@empty\si@num@mantsign\@empty
-     \ifsi@num@delplus
-       \expandafter\expandafter\expandafter\si@tab@mantsigntrue
-     \fi
-   \else
-     \expandafter\si@tab@mantsigntrue
-   \fi
-   \si@num@sepsign{exp}%
-   \ifx\@empty\si@num@expsign\@empty
-     \ifsi@num@delplus
-       \expandafter\expandafter\expandafter\si@tab@expsigntrue
-     \fi
-   \else
-     \expandafter\si@tab@expsigntrue
-   \fi
-   \si@opt@proctform{mant}%
-   \si@opt@proctform{exp}%
-%    \end{macrocode}
-%\changes{v1.0h}{2008/08/02}{Simplified warnings for \opt{tabformat}}
-% If both the integer and decimal parts are empty, then something has
-% probably gone wrong.
-%    \begin{macrocode}
-   \ifnum\si@tab@mantpostcnt=\z@\relax
-     \ifnum\si@tab@mantprecnt=\z@\relax
-       \si@log@err{Empty mantissa argument for tabformat}
-         {The argument `#1' contains no valid entry for
-          a mantissa\MessageBreak It should be of the
-          form `m.n', where  m and n are integers}%
-     \fi
-   \fi
-%    \end{macrocode}
-% If \opt{tabformat} has been given with
-% \opt{tabnumalign=centredecimal} active, then the alignment is
-% changed to centred.
-%    \begin{macrocode}
-   \ifsi@tab@fixed\else
-     \sisetup{tabnumalign=centre}%
-   \fi
-   \let\pm\si@num@pm
-   \let\mp\si@num@mp}
-%    \end{macrocode}
-%\begin{macro}{\si@opt@proctform}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% Processing the number further uses the \cs{si@num@digits} macro.
-% The results are stored in the appropriate counter.
-%    \begin{macrocode}
-\newcommand*{\si@opt@proctform}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \expandafter\si@ifnotmtarg\expandafter{%
-    \csname si@num@#1\endcsname}
-     {\expandafter\expandafter\expandafter\si@num@digits
-        \csname si@num@#1\endcsname\@empty\@empty}%
-   \csname si@tab@#1precnt\endcsname\z@\relax
-   \csname si@tab@#1postcnt\endcsname\z@\relax
-   \ifx\@empty\si@num@predec\@empty\else
-     \csname si@tab@#1precnt\endcsname\si@num@predec\relax
-   \fi
-   \ifx\@empty\si@num@postdec\@empty\else
-     \csname si@tab@#1postcnt\endcsname\si@num@postdec\relax
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-% The alignment of tabular material when not processed by \cs{num}
-% needs to be available.
-%    \begin{macrocode}
-\si@opt@choicekey{tabtextalign}{left,right,centre,center}
-%    \end{macrocode}
-%\begin{macro}{\si@tab@rfill@t}
-%\begin{macro}{\si@tab@lfill@t}
-% By default, centring happens on both sides of the content of
-% tabular material.
-%    \begin{macrocode}
-  {\def\si@tab@rfill@t{0.5}%
-   \def\si@tab@lfill@t{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@t{0}%
-     \def\si@tab@lfill@t{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@t{1}%
-     \def\si@tab@lfill@t{0}%
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% The alignment of unit columns for tabular material has a similar
-% control option.
-%    \begin{macrocode}
-\si@opt@choicekey{tabunitalign}{left,right,centre,center}
-%    \end{macrocode}
-%\begin{macro}{\si@tab@rfill@s}
-%\begin{macro}{\si@tab@lfill@s}
-% By default, centring happens on both sides of the content of
-% tabular material.
-%    \begin{macrocode}
-  {\def\si@tab@rfill@s{0.5}%
-   \def\si@tab@lfill@s{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@s{0}%
-     \def\si@tab@lfill@s{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@s{1}%
-     \def\si@tab@lfill@s{0}%
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@fixdp}
-%\changes{v1.1}{2008/08/22}{Modified to work with \opt{fixsf} option}
-%\begin{macro}{\si@num@dp}
-%\changes{v1.1}{2008/08/22}{Modified to work with \opt{fixsf} option}
-% To allow control of rounding, two options are needed.  One sets how
-% many fixed digits to use, the second turns this function on and
-% off.
-%    \begin{macrocode}
-\si@opt@boolkey[%
-  \ifsi@fixdp
-    \expandafter\si@fixsffalse
-  \fi]{fixdp}
-\newcount\si@num@dp
-\si@opt@key{dp}{%
-  \si@str@ifonlychrs{#1}{0123456789}
-    {\si@num@dp#1\relax
-     \si@fixdptrue
-     \si@fixsffalse}
-    {\si@log@err{Invalid input for dp option}
-      {The dp option must be given a positive integer}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@fixsf}
-%\begin{macro}{\si@num@sf}
-% A similar approach for fixing significant figures.
-%    \begin{macrocode}
-\si@opt@boolkey[%
-  \ifsi@fixsf
-    \expandafter\si@fixdpfalse
-  \fi]{fixsf}
-\newcount\si@num@sf
-\si@opt@key{sf}{%
-  \si@str@ifonlychrs{#1}{0123456789}
-    {\si@num@sf#1\relax
-     \ifnum\si@num@sf=\z@\relax
-       \si@log@warn{Setting sf=0 disables function}%
-       \si@fixsffalse
-     \else
-       \si@fixsftrue
-       \si@fixdpfalse
-     \fi}
-    {\si@log@err{Invalid input for sf option}
-      {The sf option must be given a positive integer}}}
-%    \end{macrocode}
+%
+%\subsection{Font macros}
+%
+% With the detection routines in place, the module can apply the result
+% to control the font used for output. This requires a series of font 
+% names to be available. The appropriate storage areas will be selected
+% by name, based on output type (\texttt{unit} or \texttt{value}) and
+% the family selected by the detector.
+% 
+%\begin{macro}{\_l_siunitx_number_math_mode_bool}
+%\begin{macro}{\_l_siunitx_unit_math_mode_bool}
+% Most of the variables are created by the keys system: these are not.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_number_math_mode_bool
+\bool_new:N \_l_siunitx_unit_math_mode_bool
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_number_color_tl}
+%\begin{macro}{\_siunitx_number_mathrm:n}
+%\begin{macro}{\_siunitx_number_mathsf:n}
+%\begin{macro}{\_siunitx_number_mathtt:n}
+%\begin{macro}{\_siunitx_number_textrm:}
+%\begin{macro}{\_siunitx_number_textsf:}
+%\begin{macro}{\_siunitx_number_texttt:}
+% The settings are actually created separately for numbers and units:
+% numbers first.
+%    \begin{macrocode}
+\cs_set:Npn \_siunitx_number_mathrm:n #1 { }
+\cs_set:Npn \_siunitx_number_mathsf:n #1 { }
+\cs_set:Npn \_siunitx_number_mathtt:n #1 { }
+\cs_set_nopar:Npn \_siunitx_number_textrm: { }
+\cs_set_nopar:Npn \_siunitx_number_textsf: { }
+\cs_set_nopar:Npn \_siunitx_number_texttt: { }
+\keys_define:nn { siunitx } {
+  number-color  .tl_set:N    = \_l_siunitx_number_color_tl,
+  number-math-rm .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_mathrm:n ##1 { #1 {##1} } },
+  number-math-sf .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_mathsf:n ##1 { #1 {##1} } },
+  number-math-tt .code:n  = 
+    { \cs_set_nopar:Npn \_siunitx_number_mathtt:n ##1 { #1 {##1} } },
+  number-mode .choice:,
+  number-mode / math .code:n = 
+    { \bool_set_true:N \_l_siunitx_number_math_mode_bool },
+  number-mode / text .code:n =
+    { \bool_set_false:N \_l_siunitx_number_math_mode_bool },
+  number-text-rm .code:n  = 
+    { \cs_set_nopar:Npn \_siunitx_number_textrm: {#1} },
+  number-text-sf .code:n  = 
+    { \cs_set_nopar:Npn \_siunitx_number_textsf: {#1} },
+  number-text-tt .code:n  = 
+    { \cs_set_nopar:Npn \_siunitx_number_texttt: {#1} }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@tabautofit}
-% To apply rounding automatically in a table, a separate option is
-% used.
-%    \begin{macrocode}
-\si@opt@boolkey{tabautofit}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@xspace}
-% Unit macros on their own may need \pkg{xpsace}.
-%    \begin{macrocode}
-\si@opt@boolkey{xspace}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@prespace}
-%    \begin{macrocode}
-\si@opt@boolkey
-  [\si@unt@numfalse
-   \ifsi@prespace
-     \si@unt@numtrue
-  \fi]
-  {prespace}
+%\end{macro}  
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%    
+%\begin{macro}{\_l_siunitx_unit_color_tl}
+%\begin{macro}{\_siunitx_unit_mathrm:n}
+%\begin{macro}{\_siunitx_unit_mathsf:n}
+%\begin{macro}{\_siunitx_unit_mathtt:n}
+%\begin{macro}{\_siunitx_unit_textrm:}
+%\begin{macro}{\_siunitx_unit_textsf:}
+%\begin{macro}{\_siunitx_unit_texttt:}
+% Units look exactly the same. 
+%    \begin{macrocode}
+\cs_set_nopar:Npn \_siunitx_unit_mathrm: { }
+\cs_set_nopar:Npn \_siunitx_unit_mathsf: { }
+\cs_set_nopar:Npn \_siunitx_unit_mathtt: { }
+\cs_set_nopar:Npn \_siunitx_unit_textrm: { }
+\cs_set_nopar:Npn \_siunitx_unit_textsf: { }
+\cs_set_nopar:Npn \_siunitx_unit_texttt: { }
+\keys_define:nn { siunitx } {
+  unit-color  .tl_set:N  = \_l_siunitx_unit_color_tl,
+  unit-math-rm .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_mathrm:n ##1 { #1 {##1} } },
+  unit-math-sf .code:n = 
+    { \cs_set_nopar:Npn \_siunitx_unit_mathsf:n ##1 { #1 {##1} } },
+  unit-math-tt .code:n = 
+    { \cs_set_nopar:Npn \_siunitx_unit_mathtt:n ##1 { #1 {##1} } },
+  unit-mode .choice:,
+  unit-mode / math .code:n = 
+    { \bool_set_true:N \_l_siunitx_unit_math_mode_bool },
+  unit-mode / text .code:n = 
+    { \bool_set_false:N \_l_siunitx_unit_math_mode_bool },
+  unit-text-rm .code:n = 
+    { \cs_set_nopar:Npn \_siunitx_unit_textrm: {#1} },
+  unit-text-sf .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_textsf: {#1} },
+  unit-text-tt .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_texttt: {#1} }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@allowoptarg}
-% For \unitsdef users, a method to absorb optional arguments is
-% needed.
+%\end{macro}
+%\end{macro}  
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+% The general settings are all meta-keys. A few initial values are set
+% here as they are needed for everything to work.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  color .meta:n = 
+    {
+      number-color = #1,
+      unit-color   = #1
+    },
+  math-rm .meta:n = 
+    {
+      number-math-rm = #1,
+      unit-math-rm   = #1
+    },
+  math-sf .meta:n = 
+    {
+      number-math-sf = #1,
+      unit-math-sf   = #1
+    },
+  math-tt .meta:n = 
+    {
+      number-math-tt = #1,
+      unit-math-tt   = #1
+    },
+  mode .choice:,
+  mode / math .meta:n = 
+    {
+      number-mode = math,
+      unit-mode   = math
+    },
+  mode / text .meta:n = 
+    {
+      number-mode = text,
+      unit-mode   = text
+    },
+  text-rm .meta:n = 
+    {
+      number-text-rm = #1,
+      unit-text-rm   = #1
+    },
+  text-sf .meta:n = 
+    {
+      number-text-sf = #1,
+      unit-text-sf   = #1
+    },
+  text-tt .meta:n = 
+    {
+      number-text-tt = #1,
+      unit-text-tt   = #1
+    }
+}
+\keys_set:nn { siunitx } {
+  math-rm     = \mathrm,
+  math-sf     = \mathsf,
+  math-tt     = \mathtt,
+  number-mode = math,
+  text-rm     = \rmfamily,
+  text-sf     = \sffamily,
+  text-tt     = \ttfamily,
+}
+%    \end{macrocode}
+%    
+% Some packages and classes (for example \pkg{beamer}) set the default 
+% family to be something other than serif family. A one-off detection 
+% will make life easier
+% all round.
 %    \begin{macrocode}
-\si@opt@boolkey{allowoptarg}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@allowlitunits}
-% To allow literal input in units.
-%    \begin{macrocode}
-\si@opt@boolkey{allowlitunits}
-%    \end{macrocode}
-%\end{macro}
-%\changes{v1.1d}{2008/10/29}{Minor bug with \opt{per} option fixed}
-%\begin{macro}{\ifsi@frac}
-%\begin{macro}{\ifsi@slash}
-%\begin{macro}{\ifsi@stickyper}
-% The option processing for formatting units with \cs{per} in them
-% needs two switches.
-%    \begin{macrocode}
-\newif\ifsi@slash
-\newif\ifsi@frac
-\si@opt@boolkey{stickyper}
-\si@opt@choicekey[reciprocal]{per}
-  {reciprocal,rp,power,slash,frac,fraction}
-  {\si@slashfalse
-   \si@fracfalse
-   \let\si@frac\si@frc@frac
-   \renewcommand*{\si@tempb}{slash}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-     \si@slashtrue
-     \let\si@frac\si@frc@slash
-   \fi
-   \renewcommand*{\si@tempb}{frac}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-   \fi
-   \renewcommand*{\si@tempb}{fraction}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@slash}
-% For the \opt{slash} option, the separator can be customised.
-%    \begin{macrocode}
-\si@opt@xchoicekey{slash}{slash}{slash}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@repeatunits}
-%\begin{macro}{\ifsi@addunitpower}
-% An option is needed for cases where units should be repeated.
-%    \begin{macrocode}
-\newif\ifsi@repeatunits
-\newif\ifsi@addunitpower
-\si@opt@choicekey[true]{repeatunits}{true,false,power}
-  {\si@repeatunitsfalse
-   \si@addunitpowerfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@repeatunitstrue
-   \fi
-   \renewcommand*{\si@tempb}{power}%
-   \ifx\si@tempa\si@tempb
-     \si@addunitpowertrue
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@trapambigfrac}
-%\begin{macro}{\si@closefrac}
-%\begin{macro}{\si@openfrac}
-% Macros for the right and left brackets added to potentially
-% ambiguous denominators.
-%    \begin{macrocode}
-\si@opt@boolkey{trapambigfrac}
-\si@opt@cmdkeys{closefrac,openfrac}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% In the case of fractional handling of the \cs{per} operator,
-% further refinement is available.
-%    \begin{macrocode}
-\si@opt@choicekey[frac]{fraction}
-  {frac,nicefrac,nice,sfrac,xfrac,uglyfrac,ugly}
-  {\let\si@frac\si@frc@frac
-   \renewcommand*{\si@tempb}{nicefrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@nice
-   \fi
-   \renewcommand*{\si@tempb}{uglyfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@ugly
-   \fi
-   \renewcommand*{\si@tempb}{nice}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@nice
-   \fi
-   \renewcommand*{\si@tempb}{sfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@sfrac
-   \fi
-   \renewcommand*{\si@tempb}{xfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@sfrac
-   \fi
-   \renewcommand*{\si@tempb}{ugly}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@ugly
-   \fi}
-%    \end{macrocode}
-%\begin{macro}{\si@load}
-%\begin{macro}{\si@noload}
-% Loading of support files is controlled by two keys.  The first
-% defines a list of files that may be loaded, the second a list that
-% will not.  This makes it easy to exclude a single file from a long
-% list.
-%    \begin{macrocode}
-\si@opt@cmdkeys{load,noload}
-\si@opt@key{alsoload}{\si@addtolist{\si@load}{#1}}
-\AtEndOfPackage{
-  \si@opt@disablekey{load}
-    {Configuration files can only be used\MessageBreak
-     when loading package}
-  \si@opt@disablekey{noload}
-    {Configuration files can only be used\MessageBreak
-     when loading package}}
-\AtEndOfPackage{
-  \si@opt@key{alsoload}{%
-    \@for\si@tempa:=#1\do{\si@loadfile{\si@tempa}}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@colourunits}
-%\begin{macro}{\ifsi@colourvalues}
-%\begin{macro}{\si@unitcolour}
-%\begin{macro}{\si@valuecolour}
-% Colour is turned on and off using two switches and the appropriate
-% options.  US spellings are also provided.
-%    \begin{macrocode}
-\si@opt@boolkey{colourunits}
-\si@opt@boolkey{colourvalues}
-\si@opt@choicekey[true]{colorunits}
-  {true,false}
-  {\si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-   \fi}
-\si@opt@choicekey[true]{colorvalues}
-  {true,false}
-  {\si@colourvaluesfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourvaluestrue
-   \fi}
-\si@opt@choicekey[true]{colorall}
-  {true,false}
-  {\si@colourvaluesfalse
-   \si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-     \si@colourvaluestrue
-   \fi}
-\si@opt@choicekey[true]{colourall}
-  {true,false}
-  {\si@colourvaluesfalse
-   \si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-     \si@colourvaluestrue
-   \fi}
-\si@opt@cmdkeys{unitcolour,valuecolour}
-\si@opt@key{unitcolor}{\sisetup{unitcolour=#1}}
-\si@opt@key{valuecolor}{\sisetup{valuecolour=#1}}
-\si@opt@key{colour}{\sisetup{unitcolour=#1,valuecolour=#1}}
-\si@opt@key{color}{\sisetup{unitcolour=#1,valuecolour=#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@colourneg}
-%\begin{macro}{\si@negcolour}
-% The set up for colouring negative numbers is similar.
-%    \begin{macrocode}
-\si@opt@boolkey{colourneg}
-\si@opt@choicekey[true]{colorneg}
-  {true,false}
-  {\si@colournegfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colournegtrue
-   \fi}
-\si@opt@cmdkeys{negcolour}
-\si@opt@key{negcolor}{\sisetup{negcolour=#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@textOmega}
-%\begin{macro}{\si@mathsOmega}
-%\begin{macro}{\si@upOmega}
-% The various non-Latin symbols need to be handled, and given user interfaces.
-% Some definitions are more complex than others; for \si{\ohm}
-% things are easy.
-%    \begin{macrocode}
-\si@opt@cmdkeys{textOmega,mathsOmega}
-\si@opt@key{mathOmega}{\sisetup{mathsOmega=#1}}
-\newcommand*{\si@mathsOmega}{\text{\ensuremath{\si@upOmega}}}
-\newcommand*{\si@textOmega}{\ensuremath{\si@upOmega}}
-\newcommand*\si@upOmega{}
-\AtBeginDocument{
-  \ifdefined\upOmega
-    \let\si@upOmega\upOmega
-  \else
-    \let\si@upOmega\Omega
-  \fi
-}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\changes{v1.0c}{2008/06/25}{Fixed excess loading of maths fonts}
-%\begin{macro}{\si@textmu}
-%\begin{macro}{\si@mathsmu}
-%\changes{v1.2m}{2009/08/10}{Fixed clash wth \pkg{fourier} package}
-%\changes{v1.3}{2009/09/20}{Better definition for micro symbol}
-% For the \si{\micro} symbol, some direct loading of symbols is
-% needed as the maths mu sign ($\mu$) is wrong.
+\AtBeginDocument {
+  \tl_set:Nx \_l_siunitx_tmpa_tl { \familydefault }
+  \tl_if_eq:NNT \_l_siunitx_tmpa_tl \_c_siunitx_textsf_tl 
+    {
+      \@ifpackageloaded { cmbright } { }
+        { \keys_set:nn { siunitx } { math-rm = \mathsf } }
+      \keys_set:nn { siunitx } { text-rm  = \sffamily }
+    }
+  \tl_if_eq:NNT \_l_siunitx_tmpa_tl \_c_siunitx_texttt_tl 
+    {
+      \keys_set:nn { siunitx } 
+        {
+          math-rm = \mathtt,
+          text-rm  = \ttfamily
+        }
+    }
+}
+%    \end{macrocode}
+%    
+%\subsection{Output control}
+%
+% The \pkg{siunitx} output routine uses all of the font information
+% gathered earlier to print the text given in whatever font is required.
+% The low-level stuff is done here, with the calling routines expected
+% to have taken some steps first (this is to allow line breaks in the
+% appropriate places).
+% 
+%\begin{macro}{\_l_siunitx_print_arg_tl}
+% The text to print.
 %    \begin{macrocode}
-\si@opt@cmdkeys{textmu,mathsmu}
-\si@opt@key{mathmu}{\sisetup{mathsmu=#1}}
-\DeclareFontEncoding{TS1}{}{}
-\DeclareFontSubstitution{TS1}{cmr}{m}{n}
-\DeclareTextSymbol{\si@textmu}{TS1}{181}
-\DeclareTextSymbolDefault{\si@textmu}{TS1}
-\def\si@mathsmu{\text{\si@textmu}}
+\tl_new:N \_l_siunitx_print_arg_tl
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_print_type_tl}
+% The type of output (\texttt{number} or \texttt{unit}) is always 
+% needed.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_print_type_tl
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@textdegree}
-%\begin{macro}{\si@mathsdegree}
-%\begin{macro}{\si@textminute}
-%\begin{macro}{\si@mathsminute}
-%\begin{macro}{\si@textsecond}
-%\begin{macro}{\si@mathssecond}
-% The angle signs.
+%
+%\begin{macro}{\_siunitx_print:nn}
+%\begin{macro}{\_siunitx_print:nV}
+% The main printing function does everything inside a group, as 
+% there are category code and definition changes to make. First, set
+% the fonts.  Then move on to printing mode, before moving to actual
+% printing.
 %    \begin{macrocode}
-\si@opt@cmdkeys{textdegree,mathsdegree,textminute,mathsminute,
-  textsecond,mathssecond}
-\si@opt@key{mathdegree}{\sisetup{mathsdegree=#1}}
-\si@opt@key{mathminute}{\sisetup{mathsminute=#1}}
-\si@opt@key{mathsecond}{\sisetup{mathssecond=#1}}
-\newcommand*{\si@textdegree}{\ensuremath{{}^{\circ}}}
-\newcommand*{\si@mathsdegree}{{}^{\circ}}
-\newcommand*{\si@textminute}{\ensuremath{{}^{\prime}}}
-\newcommand*{\si@mathsminute}{{}^{\prime}}
-\newcommand*{\si@textsecond}{\ensuremath{{}^{\prime\prime}}}
-\newcommand*{\si@mathssecond}{{}^{\prime\prime}}
+\cs_set_protected:Npn \_siunitx_print:nn #1#2 {
+  \group_begin:
+    \tl_set:Nn \_l_siunitx_print_type_tl {#1}
+    \tl_set:Nn \_l_siunitx_print_arg_tl {#2}
+    \_siunitx_detect_font:
+    \bool_if:NF \_l_siunitx_detect_mode_bool 
+      {
+        \bool_if:cTF { _l_siunitx_ #1 _math_mode_bool } 
+          { \bool_set_true:N \_l_siunitx_font_math_mode_bool }
+          { \bool_set_false:N \_l_siunitx_font_math_mode_bool }
+      }
+    \_siunitx_print_aux:
+  \group_end:
+}
+\cs_generate_variant:Nn \_siunitx_print:nn { nV }
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%\begin{macro}[aux]{\_siunitx_print_aux:}
+% The various font changes are set up, then the correct printing
+% function is called. Everything is inside \cs{text} as this allows 
+% proper setting of the various mode settings.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_print_aux: {
+  \text 
+    {
+      \_siunitx_print_color:
+      \_siunitx_font_weight:
+      \_siunitx_font_italic:
+      \use:c 
+        { 
+          _siunitx_ \_l_siunitx_print_type_tl _  
+          text \_l_siunitx_font_family_tl :
+        }
+      \bool_if:NTF \_l_siunitx_font_math_mode_bool 
+        { \_siunitx_print_math: }
+        { \_siunitx_print_text: }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_print_color:}
+% The colour system checks if \pkg{color} is loaded, and only does
+% anything if it is.  This will change when LaTeX3 proper is available:
+% there will be colour out of the box!
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_print_color: {
+  \tl_if_empty:cF { _l_siunitx_ \_l_siunitx_print_type_tl _color_tl } 
+    {
+      \color 
+        {
+          \tl_use:c { _l_siunitx_ \_l_siunitx_print_type_tl _color_tl }
+        }
+    }
+}
+\AtBeginDocument {
+  \@ifpackageloaded { color } { } 
+    { \cs_set_eq:NN \_siunitx_print_color: \scan_stop: }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_print_math:}
+%\begin{macro}{\_siunitx_print_text:}
+% Printing the text means replacing any awkward characters, which is
+% dependent on the output mode. The rest of the package uses "_" and
+% "^" to represent sub- and superscripts, respectively. In this way, 
+% mode decisions can be delayed as long as possible.  The
+% \pkg{underscore} package may make "_" active, or more likely
+% it will be a superscript character. Both are tested for here.
+%    \begin{macrocode}
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+  \char_set_lccode:nn { `\! } { `\_ }
+  \char_make_active:N \!
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected_nopar:Npn \_siunitx_print_math: 
+    {
+      \ensuremath 
+        {
+          \use:c 
+            {
+              _siunitx_ \_l_siunitx_print_type_tl _ 
+              math \_l_siunitx_font_family_tl :n
+            } 
+              { \_l_siunitx_print_arg_tl }
+        }
+    }
+  \cs_set_protected_nopar:Npn \_siunitx_print_text: 
+    {
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { @ } 
+        { \_siunitx_print_text_sub:n }
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { ! } 
+        { \_siunitx_print_text_sub:n }
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { ^ } 
+        { \_siunitx_print_text_super:n }
+      \_l_siunitx_print_arg_tl
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_print_text_sub:n}
+%\begin{macro}[aux]{\_siunitx_print_text_sub_super:n}
+%\begin{macro}{\_siunitx_print_text_super:n}
+% The appropriate macros for sub- and superscript in text mode ensure
+% the appearance is the same as math mode. As "_" is a letter, there
+% is the need to do a category-code juggle. The search and replace 
+% code for superscripts deals with the case where a literal number has
+% been given with text mode printing.
+%    \begin{macrocode}
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected:Npn \_siunitx_print_text_sub:n #1 
+    { 
+      \cs_set:Npn \_siunitx_print_text_sub_super:n ##1
+        {
+          \ensuremath 
+            { 
+              @ { \text {#1} } 
+              ^ { \text {##1} }
+            }
+        }
+      \peek_meaning_remove:NTF \_siunitx_print_text_super:n
+        { \_siunitx_print_text_sub_super:n }
+        { \ensuremath { @ { \text {#1} } } }
+    }
+}
+\cs_set_protected:Npn \_siunitx_print_text_sub_super:n { }
+\cs_set_protected:Npn \_siunitx_print_text_super:n #1 {
+  \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+  \tl_replace_all_in:Nnn \_l_siunitx_tmpa_tl { - } 
+    { \_c_siunitx_minus_tl }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \exp_not:N \ensuremath
+        {
+          ^ { \exp_not:N \text { \exp_not:V \_l_siunitx_tmpa_tl } }
+        }
+    }
+  \_l_siunitx_tmpa_tl
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@textcelsius}
-%\changes{v1.1e}{2008/11/18}{Bug fix in appearance}
-%\begin{macro}{\si@mathscelsius}
-% Finally, degrees Celsius, which may need the degree symbol.
-%    \begin{macrocode}
-\si@opt@cmdkeys{textcelsius,mathscelsius}
-\si@opt@key{mathcelsius}{\sisetup{mathscelsius=#1}}
-\newcommand*{\si@textcelsius}{%
-  \si@textdegree\kern-\scriptspace C}
-\newcommand*{\si@mathscelsius}{%
-  \si@mathsdegree\kern-\scriptspace C}
+%\end{macro}
+%
+%\subsection{Pre-processing numbers}
+%
+% Before the main parsing routine can be called, there is a need to 
+% pre-process the input. The possibility that the data in can contain
+% more than one number needs to be handled.
+% 
+%\begin{macro}{\_l_siunitx_input_product_tl}
+%\begin{macro}{\_l_siunitx_input_quotient_tl}
+% There are a couple of settings which are created here as they are used
+% only for pre-processing.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  input-product  .tl_set:N = \_l_siunitx_input_product_tl,
+  input-quotient .tl_set:N = \_l_siunitx_input_quotient_tl,
+}
+\keys_set:nn { siunitx } {
+  input-product  = x,
+  input-quotient = /
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@textringA}
-%\begin{macro}{\si@mathsringA}
-% The \si{\angstrom} sign.
+%
+%\begin{macro}{\_l_siunitx_number_arg_tl}
+%\begin{macro}{\_l_siunitx_number_next_tl}
+% Storage for the pre-parsed material.  The \texttt{arg} variable 
+% contains the current argument, the \texttt{next} variable contains
+% anything held-over for the next round.
 %    \begin{macrocode}
-\si@opt@cmdkeys{textringA,mathsringA}
-\si@opt@key{mathringA}{\sisetup{mathsringA=#1}}
-\newcommand*{\si@textringA}{\AA}
-\newcommand*{\si@mathsringA}{\text{\AA}}
+\tl_new:N \_l_siunitx_number_arg_tl
+\tl_new:N \_l_siunitx_number_next_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@redefsymbols}
-% A flag for using \pkg{textcomp} and \pkg{upgreek} to provide better
-% symbols.
+%
+%\begin{macro}{\_l_siunitx_number_multi_tl}
+% For products and quotients, a way of feeding information back.
 %    \begin{macrocode}
-\si@opt@boolkey{redefsymbols}
-\AtBeginDocument{
-  \si@opt@disablekey{redefsymbols}
-    {Symbols can only be redefined\MessageBreak
-     when loading siunitx}}
+\tl_new:N \_l_siunitx_number_multi_tl
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@eVcorra}
-%\begin{macro}{\si@eVcorrb}
+%
+%\begin{macro}{\_l_siunitx_number_denominator_tl}
+%\begin{macro}{\_l_siunitx_number_numerator_tl}
+% When searching for quotients, some more storage is needed.
 %    \begin{macrocode}
-\newlength\si@eVcorra
-\newlength\si@eVcorrb
-\si@opt@key{eVcorra}{\setlength\si@eVcorra{#1}}
-\si@opt@key{eVcorrb}{\setlength\si@eVcorrb{#1}}
+\tl_new:N \_l_siunitx_number_denominator_tl
+\tl_new:N \_l_siunitx_number_numerator_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@tophrase}
-% The phrase for ``to'' in a range.
+%
+%\begin{macro}{\_siunitx_number_preprocess:n}
+%\begin{macro}{\_siunitx_number_preprocess:V}
+% The pre-processor starts with the obvious: the most likely outcome is
+% that all of the argument is passed through unchanged.
 %    \begin{macrocode}
-\si@opt@xchoicekey{tophrase}{to,dots,ndash,dash}{to}
+\cs_set_protected:Npn \_siunitx_number_preprocess:n #1 {
+  \_siunitx_number_preprocess_init:
+  \tl_set:Nn \_l_siunitx_number_arg_tl {#1}
+  \_siunitx_number_preprocess_product:
+  \tl_if_empty:NT \_l_siunitx_number_multi_tl 
+    { \_siunitx_number_preprocess_quotient: }
+}
+\cs_generate_variant:Nn \_siunitx_number_preprocess:n { V }
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@trapambigrange}
-%\begin{macro}{\si@openrange}
-%\begin{macro}{\si@closerange}
-% Trapping awkward ranges.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_preprocess_init:}
+% A little initialisation as normal.
 %    \begin{macrocode}
-\si@opt@boolkey{trapambigrange}
-\si@opt@cmdkeys{openrange,closerange}
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_init: {
+  \bool_set_false:N \_l_siunitx_error_bool
+  \tl_clear:N \_l_siunitx_number_multi_tl
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_preprocess_product:}
+%\begin{macro}[aux]{\_siunitx_number_preprocess_product_aux:N}
+% Rather than search through the entire argument, we use the 
+% delimited-argument trick.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_product: {
+  \tl_map_function:NN \_l_siunitx_input_product_tl
+    \_siunitx_number_preprocess_product_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_preprocess_product_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_number_arg_tl {#1} 
+    {
+      \cs_set:Npn \_siunitx_tmp:w ##1 #1 ##2 \q_stop 
+        {
+          \tl_set:Nn \_l_siunitx_number_arg_tl {##1}
+          \tl_set:Nn \_l_siunitx_number_next_tl {##2}
+          \tl_set:Nn \_l_siunitx_number_multi_tl { product }      
+        }
+      \exp_after:wN \_siunitx_tmp:w \_l_siunitx_number_arg_tl \q_stop
+      \tl_if_empty:NT \_l_siunitx_number_arg_tl
+        { \_siunitx_error:n { starting-product-token } }
+      \tl_if_empty:NT \_l_siunitx_number_next_tl 
+        { \_siunitx_error:n { ending-product-token } }
+      \tl_map_break:
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@locale}
-%\begin{macro}{\si@loctolang}
-% Handling typographic conventions needs three keys.  \opt{locale} is
-% used to set the locale, \opt{loctolang} to bind to \pkg{babel}.
+%
+%\begin{macro}{\_siunitx_number_preprocess_quotient:}
+%\begin{macro}[aux]{\_siunitx_number_preprocess_quotient_aux:N}
+% For the quotient, only one token can appear in each part. So there
+% is an additional error check.
 %    \begin{macrocode}
-\si@opt@key{locale}{%
-  \si@loc@load{#1}%
-  \si@loc@set{#1}}%
-\si@opt@key{loctolang}{\si@loc@ltol{#1}}
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_quotient: {
+  \tl_map_function:NN \_l_siunitx_input_quotient_tl
+    \_siunitx_number_preprocess_quotient_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_preprocess_quotient_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_number_arg_tl {#1} 
+    {
+      \cs_set:Npn \_siunitx_tmp:w ##1 #1 ##2 \q_stop 
+        {
+          \tl_set:Nn \_l_siunitx_number_numerator_tl {##1}
+          \tl_set:Nn \_l_siunitx_number_denominator_tl {##2}     
+          \tl_set:Nn \_l_siunitx_number_multi_tl { quotient } 
+        }
+      \exp_after:wN \_siunitx_tmp:w \_l_siunitx_number_arg_tl \q_stop
+      \tl_if_empty:NT \_l_siunitx_number_numerator_tl 
+        { \_siunitx_error:n { starting-quotient-token } }
+      \tl_if_empty:NT \_l_siunitx_number_denominator_tl
+        { \_siunitx_error:n { ending-quotient-token } }
+      \tl_if_in:NnT \_l_siunitx_number_denominator_tl {#1}
+        { \_siunitx_error:n { duplicate-quotient-token } }
+      \tl_map_break:
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %
-%\subsection{Compatibility options}
-%\begin{macro}{\ifsi@old@ugly}
-%\begin{macro}{\ifsi@old@nice}
-%\begin{macro}{\ifsi@old@loose}
-%\begin{macro}{\ifsi@old@tight}
-% With the options for the package set up, the next stage is to
-% provide support for users of the older packages.  These all set up
-% switches, but do not do anything.  That is left to the emulation
-% files, loaded at the end of the package. First of all, the
-% \units options are dealt with; there are not many.
+%\subsection{Parsing numbers}
+%
+% The parser is designed to be relativity fast, which means some code is
+% more or less duplicated to gain more speed. It is also loaded so
+% that simple numbers (such as \num{-1.23}) are parsed particularly
+% quickly. For most documents, this gain more than offsets any slight
+% losses with more complicated numbers.
+% 
+%\begin{macro}{\_c_siunitx_number_part_complex_tl}
+% A couple of the comparisons needed for checking complex numbers
+% are done using stored text. To make them a little quicker, a
+% pre-stored version of the text is stored here.
+%    \begin{macrocode}
+\tl_new:N \_c_siunitx_number_part_complex_tl
+\tl_set:Nn \_c_siunitx_number_part_complex_tl { complex }
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_number_in_complex_bool}
+%\begin{macro}{\_l_siunitx_number_in_complex_root_bool}
+%\begin{macro}{\_l_siunitx_number_in_decimal_bool}
+%\begin{macro}{\_l_siunitx_number_in_exponent_bool}
+%\begin{macro}{\_l_siunitx_number_in_first_bool}
+%\begin{macro}{\_l_siunitx_number_in_sign_bool}
+%\begin{macro}{\_l_siunitx_number_in_uncert_bool}
+%\begin{macro}{\_l_siunitx_number_in_value_bool}
 %    \begin{macrocode}
-\si@opt@compatkey{units}{ugly}
-\si@opt@compatkey{units}{nice}
-\si@opt@compatkey{units}{loose}
-\si@opt@compatkey{units}{tight}
+\bool_new:N \_l_siunitx_number_in_complex_bool
+\bool_new:N \_l_siunitx_number_in_complex_root_bool
+\bool_new:N \_l_siunitx_number_in_decimal_bool
+\bool_new:N \_l_siunitx_number_in_exponent_bool
+\bool_new:N \_l_siunitx_number_in_first_bool
+\bool_new:N \_l_siunitx_number_in_sign_bool
+\bool_new:N \_l_siunitx_number_in_uncert_bool
+\bool_new:N \_l_siunitx_number_in_value_bool
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@OHM}
-%\begin{macro}{\ifsi@old@ohm}
-%\begin{macro}{\ifsi@old@redef-gensymb}
-%\begin{macro}{\ifsi@gensymb}
-% The \unitsdef package is unfortunately much more profligate with
-% options. The first set are to do with support for \pkg{gensymb}.
-%    \begin{macrocode}
-\si@opt@compatkey{unitsdef}{OHM}
-\si@opt@compatkey{unitsdef}{ohm}
-\si@opt@compatkey{unitsdef}{redef-gensymb}
-\newif\ifsi@gensymb
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@LITER}
-%\begin{macro}{\ifsi@old@liter}
-%\begin{macro}{\ifsi@old@noxspace}
-%\begin{macro}{\ifsi@old@noconfig}
-% The second set are more general functionality.
+%
+%\begin{macro}{\_l_siunitx_number_in_prop}
+% The parsed number is stored in a property list as its constituent 
+% parts.
 %    \begin{macrocode}
-\si@opt@compatkey{unitsdef}{LITER}
-\si@opt@compatkey{unitsdef}{liter}
-\si@opt@compatkey{unitsdef}{noxspace}
-\si@opt@compatkey{unitsdef}{noconfig}
+\prop_new:N \_l_siunitx_number_in_prop
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_number_parsed_tl}
+% Each part of the number parsed has to be built up in a token list.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_number_parsed_tl
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_number_part_tl}
+%\begin{macro}{\_l_siunitx_number_part_decimal_tl}
+%\begin{macro}{\_l_siunitx_number_part_decimal_marker_tl}
+%\begin{macro}{\_l_siunitx_number_part_integer_tl}
+%\begin{macro}{\_l_siunitx_number_part_sign_tl}
+%\begin{macro}{\_l_siunitx_number_part_uncert_tl}
+% The names of various parts of a number are set up as stored values.
+% This lets some code be used for different parts of a number, while
+% pre-storing everything brings a performance (and clarity) benefit.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_number_part_tl
+\tl_new:N \_l_siunitx_number_part_decimal_tl
+\tl_new:N \_l_siunitx_number_part_decimal_marker_tl
+\tl_new:N \_l_siunitx_number_part_integer_tl
+\tl_new:N \_l_siunitx_number_part_sign_tl
+\tl_new:N \_l_siunitx_number_part_uncert_tl
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@noabbr}
-%\begin{macro}{\ifsi@old@noamperageabbr}
-%\begin{macro}{\ifsi@old@nofrequncyabbr}
-%\begin{macro}{\ifsi@old@nomolabbr}
-%\begin{macro}{\ifsi@old@novoltageabbr}
-%\begin{macro}{\ifsi@old@novolumeabbr}
-%\begin{macro}{\ifsi@old@noweightabbr}
-%\begin{macro}{\ifsi@old@noenergyabbr}
-%\begin{macro}{\ifsi@old@nolengthabbr}
-%\begin{macro}{\ifsi@old@notimeabbr}
-% The final set are for control of abbreviations, and are a good
-% demonstration of why to use \pkg{xkeyval}!
-%    \begin{macrocode}
-\si@opt@compatkey{unitsdef}{noabbr}
-\si@opt@compatkey{unitsdef}{noampereageabbr}
-\si@opt@compatkey{unitsdef}{nofrequncyabbr}
-\si@opt@compatkey{unitsdef}{nomolabbr}
-\si@opt@compatkey{unitsdef}{novoltageabbr}
-\si@opt@compatkey{unitsdef}{novolumeabbr}
-\si@opt@compatkey{unitsdef}{noweightabbr}
-\si@opt@compatkey{unitsdef}{noenergyabbr}
-\si@opt@compatkey{unitsdef}{nolengthabbr}
-\si@opt@compatkey{unitsdef}{notimeabbr}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_input_uncert_close_tl}
+%\begin{macro}{\_l_siunitx_input_complex_tl}
+%\begin{macro}{\_l_siunitx_input_decimal_tl}
+%\begin{macro}{\_l_siunitx_input_digit_tl}
+%\begin{macro}{\_l_siunitx_input_exponent_tl}
+%\begin{macro}{\_l_siunitx_input_ignore_tl}
+%\begin{macro}{\_l_siunitx_input_uncert_open_tl}
+%\begin{macro}{\_l_siunitx_input_protect_tl}
+%\begin{macro}{\_l_siunitx_input_sign_tl}
+%\begin{macro}{\_l_siunitx_input_symbol_tl}
+% The various tokens to check against when parsing are all set up here.
+% These are valid inside a single number: the pre-processor has already
+% set up the appropriate things for products and quotients.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  input-close-uncertainty .tl_set:N = \_l_siunitx_input_uncert_close_tl, 
+  input-complex-roots     .tl_set:N = \_l_siunitx_input_complex_tl,
+  input-decimal-markers   .tl_set:N = \_l_siunitx_input_decimal_tl,
+  input-digits            .tl_set:N = \_l_siunitx_input_digit_tl,
+  input-exponent-markers  .tl_set:N = \_l_siunitx_input_exponent_tl,
+  input-ignore            .tl_set:N = \_l_siunitx_input_ignore_tl,
+  input-open-uncertainty  .tl_set:N = \_l_siunitx_input_uncert_open_tl, 
+  input-protect-tokens    .tl_set:N = \_l_siunitx_input_protect_tl,
+  input-signs             .tl_set:N = \_l_siunitx_input_sign_tl,
+  input-symbols           .tl_set:N = \_l_siunitx_input_symbol_tl,
+}
+\keys_set:nn { siunitx } { % (
+  input-close-uncertainty = ),
+  input-complex-roots     = ij,
+  input-decimal-markers   = {.,},
+  input-digits            = 0123456789,
+  input-exponent-markers  = dDeE,
+  input-open-uncertainty  = (, % )
+  input-protect-tokens    = \mp\pi\pm,
+  input-signs             = +-\mp\pm,
+  input-symbols           = \pi,
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -5146,5840 +4902,3123 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@cdot}
-%\begin{macro}{\ifsi@old@thickspace}
-%\begin{macro}{\ifsi@old@mediumspace}
-%\begin{macro}{\ifsi@old@thinspace}
-%\begin{macro}{\ifsi@old@thickqspace}
-%\begin{macro}{\ifsi@old@mediumqspace}
-%\begin{macro}{\ifsi@old@thinqspace}
-% The \SIunits package has lots of options.  These ones are all
-% related to spacing.
+%
+%\begin{macro}{\_siunitx_number_in_parse:n}
+%\begin{macro}{\_siunitx_number_in_parse:V}
+%\begin{macro}[aux]{\_siunitx_number_in_parse_aux:n}
+% The parsing routine starts by replacing any formatting in the input
+% using \cs{tl_set_rescan:Nnx}. Next, there is a quick routine to
+% ensure that all signs are single tokens. The main loop then takes 
+% place, which will parse the input into the property list and also
+% set up the flags. There are then some checks and possible corrections.
 %    \begin{macrocode}
-\si@opt@compatkey{SIunits}{cdot}
-\si@opt@compatkey{SIunits}{thickspace}
-\si@opt@compatkey{SIunits}{mediumspace}
-\si@opt@compatkey{SIunits}{thinspace}
-\si@opt@compatkey{SIunits}{thickqspace}
-\si@opt@compatkey{SIunits}{mediumqspace}
-\si@opt@compatkey{SIunits}{thinqspace}
+\cs_set_protected:Npn \_siunitx_number_in_parse:n #1 {
+  \tl_if_empty:nF {#1} 
+    { 
+      \_siunitx_number_in_init:
+      \cs_set_eq:NN \_siunitx_number_in_parse_more:N
+        \_siunitx_number_in_parse_mantissa_aux:N
+      \_siunitx_number_in_parse_aux:n {#1} 
+    }
+}
+\cs_generate_variant:Nn \_siunitx_number_in_parse:n { V }
+\cs_set_protected:Npn \_siunitx_number_in_parse_aux:n #1 {
+  \tl_set_rescan:Nnx \_l_siunitx_number_arg_tl
+    {
+      \_siunitx_number_in_protect:
+      \char_make_ignore:N \~
+      \char_make_other:N \,
+      \char_make_other:N \.
+      \cs_set_eq:NN \, \prg_do_nothing:
+    }
+    {#1}
+  \_siunitx_number_in_sign_replace:N \_l_siunitx_number_arg_tl
+  \tl_map_function:NN \_l_siunitx_number_arg_tl 
+    \_siunitx_number_in_parse_loop:N
+  \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+    {
+      \bool_if:NTF \_l_siunitx_number_in_uncert_bool
+        { \_siunitx_error:nx { invalid-number } {#1} }
+        {
+          \prop_put:NVn \_l_siunitx_number_in_prop 
+            \_l_siunitx_number_part_tl { true }
+          \bool_if:NTF \_l_siunitx_number_in_decimal_bool  
+            {
+              \prop_put:NVV \_l_siunitx_number_in_prop 
+                \_l_siunitx_number_part_decimal_tl 
+                \_l_siunitx_number_parsed_tl
+            }
+            {
+              \prop_put:NVV \_l_siunitx_number_in_prop 
+                \_l_siunitx_number_part_integer_tl 
+                \_l_siunitx_number_parsed_tl
+            }
+       }     
+    }
+  \_siunitx_number_in_check:n {#1}
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_init:}
+%\begin{macro}{\_siunitx_number_in_init_part:n}
+% The set up code is divided into to parts. First, code only needed
+% once to start the entire parser. Then a second group, which is 
+% carried out at the start of each part of a number, and so is called
+% from a few places.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_init: {
+  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N 
+    \_siunitx_number_in_parse_mantissa:N  
+  \cs_set_eq:NN \_siunitx_number_in_check:n 
+    \_siunitx_number_in_check_short:n
+  \tl_clear:N \_l_siunitx_number_parsed_tl
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \bool_set_false:N \_l_siunitx_error_bool
+  \bool_set_false:N \_l_siunitx_number_in_complex_bool
+  \bool_set_false:N \_l_siunitx_number_in_complex_root_bool
+  \bool_set_false:N \_l_siunitx_number_in_exponent_bool
+  \bool_set_false:N \_l_siunitx_number_in_uncert_bool
+  \_siunitx_number_in_init_part:n { mantissa }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_init_part:n #1 {  
+  \bool_set_false:N \_l_siunitx_number_in_decimal_bool
+  \bool_set_true:N \_l_siunitx_number_in_first_bool
+  \bool_set_false:N \_l_siunitx_number_in_sign_bool
+  \bool_set_false:N \_l_siunitx_number_in_value_bool
+  \tl_set:Nn \_l_siunitx_number_part_tl {#1}
+  \tl_set:Nn \_l_siunitx_number_part_decimal_tl { #1 -decimal }
+  \tl_set:Nn \_l_siunitx_number_part_decimal_marker_tl 
+    { #1 -decimal-marker }
+  \tl_set:Nn \_l_siunitx_number_part_integer_tl { #1 -integer }
+  \tl_set:Nn \_l_siunitx_number_part_sign_tl { #1 -sign }
+  \tl_set:Nn \_l_siunitx_number_part_uncert_tl { #1 -uncertainty }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_protect:}
+%\begin{macro}[aux]{\_siunitx_number_in_protect_aux:N}
+% Under some circumstances (for example when loading \pkg{breqn}) 
+% some tokens do not behave safely under \texttt{x} expansion (at the
+% moment). To get round this, they are redefined here.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_protect: {
+  \tl_map_function:NN \_l_siunitx_input_protect_tl
+    \_siunitx_number_in_protect_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_in_protect_aux:N #1 {
+  \cs_set_eq:NN #1 \scan_stop:
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@amssymb}
-%\begin{macro}{\ifsi@old@squaren}
-%\begin{macro}{\ifsi@old@pstricks}
-%\begin{macro}{\ifsi@old@Gray}
-%\begin{macro}{\ifsi@old@italian}
-% These options are used by \SIunits to control clashes with other
-% packages.
+%
+%\begin{macro}{\_siunitx_number_in_sign_replace:N}
+% A short spin-out to keep the replacement of tokens clear.
 %    \begin{macrocode}
-\si@opt@compatkey{SIunits}{amssymb}
-\si@opt@compatkey{SIunits}{squaren}
-\si@opt@compatkey{SIunits}{pstricks}
-\si@opt@compatkey{SIunits}{Gray}
-\si@opt@compatkey{SIunits}{italian}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_sign_replace:N #1 {
+  \tl_replace_all_in:Nnn #1 { -+ } { \mp }
+  \tl_replace_all_in:Nnn #1 { +- } { \pm }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_error:nx} 
+%\begin{macro}{\_siunitx_number_in_parse_error:nV} 
+% There are lots of rather similar errors in the parser, all of which
+% require a \cs{tl_map_break:}. To keep life simple, this is set up 
+% here. 
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_error:nx #1#2 {
+  \_siunitx_error:nx {#1} { \exp_not:n {#2} }
+  \tl_map_break:
+}
+\cs_generate_variant:Nn \_siunitx_number_in_parse_error:nx { nV }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_loop:N}
+%\begin{macro}{\_siunitx_number_in_parse_more:N}
+% The main loop is set up as a place holder, as the definition is
+% varied to keep things fast. There is also a place holder for the 
+% extended routing for normal mantissas.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_loop:N #1 { }
+\cs_set_protected:Npn \_siunitx_number_in_parse_more:N #1 { }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@textstyle}
-%\begin{macro}{\ifsi@old@binary}
-%\begin{macro}{\ifsi@old@noams}
-%\begin{macro}{\ifsi@old@derivedinbase}
-%\begin{macro}{\ifsi@old@derived}
-% The miscellaneous options.
+%
+%\begin{macro}{\_siunitx_number_in_parse_restricted:N}
+% When parsing numbers for the \cs{ang} function, no extended input 
+% is permitted at all.
 %    \begin{macrocode}
-\si@opt@compatkey{SIunits}{textstyle}
-\si@opt@compatkey{SIunits}{binary}
-\si@opt@compatkey{SIunits}{noams}
-\si@opt@compatkey{SIunits}{derivedinbase}
-\si@opt@compatkey{SIunits}{derived}
+\cs_set_protected:Npn \_siunitx_number_in_parse_restricted:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { 
+      \_siunitx_number_in_parse_error:nx  
+        { restricted-number } {#1} 
+    }
+    { 
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        { 
+          \_siunitx_number_in_parse_error:nV 
+            { restricted-number } \_l_siunitx_number_arg_tl 
+        }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            { 
+              \_siunitx_number_in_parse_error:nV 
+                { restricted-number } \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \_siunitx_number_in_parse_error:nV 
+                    { restricted-number } \_l_siunitx_number_arg_tl
+                }
+                {
+                  \_siunitx_number_in_parse_error:nx 
+                    { restricted-number } {#1} 
+                }
+            }
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_complex:N}
+% After a complex root when the root is \emph{after} the number, there
+% are a very limited range of legitimate tokens. Thus most cases can be
+% trapped with a modified parser.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_complex:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { 
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+        \_siunitx_number_in_parse_mantissa:N
+      \_siunitx_number_in_exponent:N #1 
+    }
+    { 
+      \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+        {
+          \_siunitx_number_in_parse_error:nV 
+            { misplaced-complex-root-token } 
+            \_l_siunitx_number_arg_tl
+        }
+    }
+}
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_exponent:N}
+% When processing an exponent, the \enquote{extended} part of the
+% number which is valid in a mantissa is no longer needed. So the
+% auxiliary function is pointed to a series of errors instead.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_exponent:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { 
+      \_siunitx_number_in_parse_error:nx  
+        { duplicate-exponent-token } { \token_to_str:N #1 } 
+    }
+    { 
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        { 
+          \_siunitx_number_in_parse_error:nV 
+            { invalid-token-in-exponent } \_l_siunitx_number_arg_tl 
+        }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            { 
+              \_siunitx_number_in_parse_error:nV 
+                { invalid-token-in-exponent } \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \_siunitx_number_in_parse_error:nV 
+                    { invalid-token-in-exponent } 
+                    \_l_siunitx_number_arg_tl
+                }
+                {
+                  \_siunitx_number_in_parse_error:nx 
+                    { invalid-token-in-number } {#1} 
+                }
+            }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_mantissa:N}
+%\begin{macro}{\_siunitx_number_in_parse_mantissa_aux:N}
+% For the mantissa, most things are valid. The procedure is split
+% into two parts, with the simple symbols handled here and the more
+% complex ones in a second part(which needs to be varied). Essentially
+% everything here is a comparison, done so that the code is a fast as
+% possible.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_mantissa:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_digit_tl {#1}
+    { \_siunitx_number_in_digit:N #1 }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_decimal_tl {#1}
+        { \_siunitx_number_in_decimal:N #1 }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+            { \_siunitx_number_in_sign:N #1 }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_symbol_tl {#1}
+                { 
+                  \prop_put:Nnn \_l_siunitx_number_in_prop { symbolic } 
+                    { true }
+                  \_siunitx_number_in_digit:N #1
+                }
+                { 
+                  \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+                    { \_siunitx_number_in_parse_more:N #1 }
+                } 
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_mantissa_aux:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { \_siunitx_number_in_exponent:N #1 }
+    { 
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        { \_siunitx_number_in_uncert_open:N #1 }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            { 
+              \_siunitx_number_in_parse_error:nx 
+                { misplaced-uncertainty-token } {#1} 
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                { \_siunitx_number_in_complex:N #1 }
+                {
+                  \_siunitx_number_in_parse_error:nx 
+                    { invalid-token-in-number } {#1}
+                }  
+            }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_parse_uncert:N}
+% Within uncertainties, the range of tokens is limited. An alternative
+% parsing system can therefore be used.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_parse_uncert:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_digit_tl {#1}
+    { \_siunitx_number_in_digit:N #1 }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_decimal_tl {#1}
+        { 
+          \_siunitx_number_in_parse_error:nV 
+            { invalid-token-in-uncertainty } 
+            \_l_siunitx_number_arg_tl
+        }         
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+            {
+              \_siunitx_number_in_parse_error:nV 
+                { invalid-token-in-uncertainty } 
+                \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_symbol_tl {#1}
+                { 
+                  \prop_put:Nnn \_l_siunitx_number_in_prop { symbolic }
+                    { true }
+                  \_siunitx_number_in_digit:N #1
+                }
+                { 
+                  \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+                    { 
+                      \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl 
+                        {#1}
+                        { \_siunitx_number_in_uncert_close:N #1 }
+                        {
+                          \_siunitx_number_in_parse_error:nV 
+                            { invalid-token-in-uncertainty } 
+                            \_l_siunitx_number_arg_tl
+                        }
+                    }
+                } 
+            }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@old@noprefixcmds}
-% The \pkg{hepunits} package only has one option.
+%
+%\begin{macro}{\_siunitx_number_in_parse_uncert_after:N}
+% After an uncertainty, there is once again a very limited range of
+% tokens that can be present in a valid number.
 %    \begin{macrocode}
-\si@opt@compatkey{hepunits}{noprefixcmds}
+\cs_set_protected:Npn \_siunitx_number_in_parse_uncert_after:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { 
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+        \_siunitx_number_in_parse_mantissa:N
+      \_siunitx_number_in_exponent:N #1 
+    }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+        { 
+          \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+            \_siunitx_number_in_parse_mantissa:N
+          \_siunitx_number_in_sign:N #1
+        }
+        {
+          \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+            { 
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+                    \_siunitx_number_in_parse_mantissa:N
+                  \_siunitx_number_in_complex:N #1
+                }
+                {         
+                  \_siunitx_number_in_parse_error:nV { invalid-number }
+                    \_l_siunitx_number_arg_tl 
+                }
+            }    
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@old@english}
-%\begin{macro}{\ifsi@old@french}
-% \pkg{fancynum} provides a few options.  First the rather oddly
-% named \opt{english} and \opt{french} ones.
+%
+%\begin{macro}{\_siunitx_number_in_complex:N}
+%\begin{macro}[aux]{\_siunitx_number_in_complex_aux:nn}
+% Only one complex root token can be give, hence the initial test.
+% More tests are needed for complex numbers than other systems, so
+% the additional ones are turned on, followed by some flag setting.
+% The complex root is stored, then there is a check to see if the
+% root is at the end of the number: if it is, prevent any more tokens 
+% being added.
 %    \begin{macrocode}
-\si@opt@compatkey{fancynum}{english}
-\si@opt@compatkey{fancynum}{french}
+\cs_set_protected:Npn \_siunitx_number_in_complex:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_complex_root_bool
+    { 
+      \_siunitx_number_in_parse_error:nx 
+        { duplicate-complex-root-token } { \token_to_str:N #1 } 
+    }
+    {
+      \cs_set_eq:NN \_siunitx_number_in_check:n 
+        \_siunitx_number_in_check_full:n 
+      \bool_set_true:N \_l_siunitx_number_in_complex_root_bool
+      \prop_put:Nnn \_l_siunitx_number_in_prop { complex-root } {#1}
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+        { 
+          \cs_set_eq:NN \_siunitx_number_in_parse_loop:N 
+            \_siunitx_number_in_parse_complex:N   
+        } 
+      \bool_if:NT \_l_siunitx_number_in_decimal_bool
+        { 
+          \bool_if:NF \_l_siunitx_number_in_complex_bool
+            {
+              \prop_if_in:NnT \_l_siunitx_number_in_prop 
+                { mantissa-uncertainty }
+                {
+                  \_siunitx_number_in_complex_aux:nn 
+                    { mantissa-decimal } { complex-decimal }
+                  \_siunitx_number_in_complex_aux:nn 
+                    { mantissa-uncertainty } { complex-uncertainty }
+                }
+              \_siunitx_number_in_complex_aux:nn { mantissa-integer }
+                { complex-integer }
+              \_siunitx_number_in_complex_aux:nn 
+                { mantissa-decimal-marker } { complex-decimal-marker }
+              \prop_del:Nn \_l_siunitx_number_in_prop { mantissa }
+              \prop_put:Nnn \_l_siunitx_number_in_prop { complex }
+                { true }
+            }
+        } 
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { mantissa-sign }
+            {                
+              \_siunitx_number_in_complex_aux:nn { mantissa-sign }
+                { complex-sign }
+            }
+        }  
+      \bool_set_true:N \_l_siunitx_number_in_complex_bool 
+      \bool_set_false:N \_l_siunitx_number_in_first_bool 
+      \_siunitx_number_in_init_part:n { complex } 
+      \prop_if_in:NnT \_l_siunitx_number_in_prop 
+        { complex-decimal-marker }
+        { \bool_set_true:N \_l_siunitx_number_in_decimal_bool }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop 
+        { complex-sign }
+        { \bool_set_true:N \_l_siunitx_number_in_sign_bool }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_complex_aux:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_del:Nn  \_l_siunitx_number_in_prop {#1} 
+      \prop_put:NnV \_l_siunitx_number_in_prop {#2} \_l_siunitx_tmpa_tl
+   }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@tight}
-%\begin{macro}{\ifsi@old@loose}
-% A couple for spacing multiplication.
+%
+%\begin{macro}{\_siunitx_number_in_decimal:N}
+% Only one decimal marker allowed, so a test for this. If an integer
+% part has been found, it is saved. The flag for the number being
+% found is not set unless there is an integer, to watch for the case
+% of invalid numbers.
 %    \begin{macrocode}
-\si@opt@compatkey{fancynum}{tight}
-\si@opt@compatkey{fancynum}{loose}
+\cs_set_protected:Npn \_siunitx_number_in_decimal:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_decimal_bool 
+    { 
+      \_siunitx_number_in_parse_error:nx { duplicate-decimal-token } 
+        { \token_to_str:N #1 }
+    }
+    {
+      \bool_set_true:N \_l_siunitx_number_in_decimal_bool
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+        {
+          \prop_put:NVn \_l_siunitx_number_in_prop 
+            \_l_siunitx_number_part_tl { true }
+          \prop_put:NVV \_l_siunitx_number_in_prop 
+            \_l_siunitx_number_part_integer_tl 
+            \_l_siunitx_number_parsed_tl
+          \tl_clear:N \_l_siunitx_number_parsed_tl 
+        }
+      \prop_put:NVn \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_decimal_marker_tl {#1}
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_digit:N}
+% For digits, only in an uncertainty can the value be stored
+% directly. Otherwise, there is a need to see if the value is non-zero.
+% This is used to drop leading zeros and to validate any sign (as zero
+% is unsigned).
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_digit:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_uncert_bool
+    { \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1} }
+    {
+      \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+        {
+          \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1}
+          \tl_if_eq:nnF {#1} { 0 } 
+            { \bool_set_true:N \_l_siunitx_number_in_value_bool }
+        }
+        {
+          \tl_if_eq:nnTF {#1} { 0 } 
+            { 
+              \prop_put:NVn \_l_siunitx_number_in_prop 
+                \_l_siunitx_number_part_tl { true }
+              \prop_put:NVn \_l_siunitx_number_in_prop 
+                \_l_siunitx_number_part_integer_tl { 0 }
+            }
+            { \bool_set_true:N \_l_siunitx_number_in_value_bool }
+          \bool_if:NT \_l_siunitx_number_in_value_bool  
+            { \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1} }
+        } 
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@old@thinspaces}
-%\begin{macro}{\ifsi@old@commas}
-%\begin{macro}{\ifsi@old@plain}
-% Three for digit separation.
+%
+%\begin{macro}{\_siunitx_number_in_exponent:N}
+% A duplicate token test starts off the code, which if passed 
+% leads to some simple storage manipulation. As exponents are 
+% more simple than the mantissa, the extra processing is swapped for
+% some that only raises errors.
 %    \begin{macrocode}
-\si@opt@compatkey{fancynum}{thinspaces}
-\si@opt@compatkey{fancynum}{commas}
-\si@opt@compatkey{fancynum}{plain}
+\cs_set_protected:Npn \_siunitx_number_in_exponent:N #1 {
+  \bool_if:NTF \_l_siunitx_number_in_exponent_bool
+    { 
+      \_siunitx_number_in_parse_error:nx { duplicate-exponent-token } 
+        { \token_to_str:N #1 }
+    }
+    {
+      \cs_set_eq:NN \_siunitx_number_in_parse_more:N
+        \_siunitx_number_in_parse_exponent:N
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl 
+        { \_siunitx_number_in_store: }
+      \bool_set_true:N \_l_siunitx_number_in_exponent_bool
+      \_siunitx_number_in_init_part:n { exponent } 
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_sign:N}
+% The code for signs is complicated by complex numbers. A sign token
+% must be the fist thing in a number, but after the real part of the
+% mantissa a second sign token can appear to start a complex number.
+% So most of the code here is to detect that case.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_sign:N #1 {
+  \bool_if:NTF \_l_siunitx_number_in_first_bool
+    {
+      \bool_set_false:N \_l_siunitx_number_in_first_bool
+      \bool_set_true:N \_l_siunitx_number_in_sign_bool
+      \prop_put:NVn \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_sign_tl {#1}
+    }
+    { 
+      \bool_if:NTF \_l_siunitx_number_in_exponent_bool
+        { 
+          \_siunitx_number_in_parse_error:nx { misplaced-sign-token } 
+            {#1}
+        }
+        {
+          \bool_if:NTF \_l_siunitx_number_in_complex_bool
+            { 
+              \_siunitx_number_in_parse_error:nx 
+                { misplaced-sign-token } {#1} 
+            }
+            { 
+              \tl_if_empty:NF \_l_siunitx_number_parsed_tl 
+                { \_siunitx_number_in_store: }
+              \cs_set_eq:NN \_siunitx_number_in_check:n 
+                \_siunitx_number_in_check_full:n  
+              \_siunitx_number_in_init_part:n { complex }
+              \prop_put:Nnn \_l_siunitx_number_in_prop 
+                { complex-sign } {#1}  
+              \bool_set_true:N \_l_siunitx_number_in_complex_bool
+            }
+        }
+    }
+}
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_in_uncert_open:N}
+%\begin{macro}{\_siunitx_number_in_uncert_close:N}
+% Opening and closing uncertainty tokens are handled separately. For
+% opening tokens, a check is made that there is something else to the
+% number before collecting material up. For the closing token, the
+% uncertainty must contain some numbers. A special loop function is then
+% set up to prevent any additional digits after the closing token.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_in_uncert_open:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N 
+    \_siunitx_number_in_parse_uncert:N
+  \bool_set_true:N \_l_siunitx_number_in_uncert_bool
+  \tl_if_empty:NTF \_l_siunitx_number_parsed_tl
+    {
+      \prop_if_in:NVF \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_integer_tl
+        {  
+          \_siunitx_number_in_parse_error:nV { invalid-number } 
+            \_l_siunitx_number_arg_tl 
+        }
+    }
+    { \_siunitx_number_in_store: }
+}
+\cs_set_protected:Npn \_siunitx_number_in_uncert_close:N #1 { 
+  \bool_set_false:N \_l_siunitx_number_in_uncert_bool
+  \tl_if_empty:NTF \_l_siunitx_number_parsed_tl
+    { 
+      \_siunitx_number_in_parse_error:nV { empty-uncertainty } 
+        \_l_siunitx_number_arg_tl
+    }
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_uncert_tl \_l_siunitx_number_parsed_tl
+      \prop_put:Nnn \_l_siunitx_number_in_prop 
+        { uncertainty } { true }
+      \tl_clear:N \_l_siunitx_number_parsed_tl
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N 
+        \_siunitx_number_in_parse_uncert_after:N   
+    }  
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@old@spaceqspace}
-% The \pkg{fancyunits} package provides one option not available with
-% \SIunits.
+%
+%\begin{macro}{\_siunitx_number_in_store:}
+% A short auxiliary function needed in various places for storing
+% either the integer or decimal part of a number, as appropriate.
 %    \begin{macrocode}
-\si@opt@compatkey{fancyunits}{spaceqspace}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_store: {
+  \prop_put:NVn \_l_siunitx_number_in_prop \_l_siunitx_number_part_tl 
+    { true }
+  \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_decimal_tl \_l_siunitx_number_parsed_tl
+    }
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_integer_tl \_l_siunitx_number_parsed_tl
+    }    
+  \tl_clear:N \_l_siunitx_number_parsed_tl 
+}
 %    \end{macrocode}
 %\end{macro}
 %
-%\subsection{Constants}
-% A number of macros are needed by the package that provide a
-% non-changing output.  These are defined here; the intention is that
-% these should not be macros that the user is likely to need to
-% alter.  All of these macros have preface \cs{si@fix@}, to flag that
-% that are intended as constants.  The package may rely on the
-% contents of these macros for functionality.
+%\begin{macro}{\_siunitx_number_in_check:n}
+%\begin{macro}{\_siunitx_number_in_check_short:n}
+%\begin{macro}{\_siunitx_number_in_check_full:n}
+% The checks needed for a number depend on whether there is a complex
+% part. In all cases, there must be some digits, as well as a sign or
+% decimal marker. There is also a check for a zero-valued input, which
+% has any sign deleted. For complex numbers, the check is needed in
+% case there was no real part.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check:n #1 { }
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check_short:n #1 { 
+  \prop_if_in:NVF \_l_siunitx_number_in_prop 
+    \_l_siunitx_number_part_integer_tl
+    {
+      \prop_if_in:NVF \_l_siunitx_number_in_prop 
+        \_l_siunitx_number_part_decimal_tl
+        { \_siunitx_error:nx { invalid-number } {#1} }
+    }
+  \bool_if:NF \_l_siunitx_number_in_value_bool 
+    { 
+      \tl_if_eq:NNF \_l_siunitx_number_part_tl 
+        \_c_siunitx_number_part_complex_tl
+        { 
+          \prop_get:NVN \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_sign_tl  \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+            {
+              \tl_set:Nx \_l_siunitx_tmpb_tl
+                { \_l_siunitx_number_part_sign_tl -deleted }
+              \prop_put:NVV \_l_siunitx_number_in_prop
+                \_l_siunitx_tmpb_tl \_l_siunitx_tmpa_tl
+            } 
+          \prop_del:NV \_l_siunitx_number_in_prop 
+            \_l_siunitx_number_part_sign_tl 
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check_full:n #1 {
+  \tl_if_eq:NNF \_l_siunitx_number_part_tl 
+    \_c_siunitx_number_part_complex_tl 
+    { \_siunitx_number_in_check_short:n {#1} }
+  \bool_if:NF \_l_siunitx_number_in_complex_root_bool
+    { 
+      \prop_get:NnN \_l_siunitx_number_in_prop { complex-sign } 
+        \_l_siunitx_tmpa_tl
+      \_siunitx_error:nV { misplaced-sign-token } \_l_siunitx_tmpa_tl
+    }
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign } 
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+        {
+          \prop_del:Nn \_l_siunitx_number_in_prop { mantissa-sign }
+          \prop_put:NnV \_l_siunitx_number_in_prop { complex-sign } 
+            \_l_siunitx_tmpa_tl
+        }
+    }
+}
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\subsection{Post-processing numbers}
 %
-%\begin{macro}{\si@fix@thin}
-%\begin{macro}{\si@fix@med}
-%\begin{macro}{\si@fix@medium}
-%\begin{macro}{\si@fix@thick}
-%\begin{macro}{\si@fix@space}
-%\changes{v1.0a}{2008/06/20}{Fixed problem with \opt{space} option}
-% First, there are the various space macros.  To allow both \opt{med}
-% and \opt{medium} to be used as a space description, two macros are
-% needed for the same output.
+% After finding the basic number in the code above, there may be some
+% manipulation to do. This covers things such as tidying up excess 
+% information and rounding numbers. Nothing is added here that is
+% for \enquote{formatting}: this is left for the output part of the 
+% system.
+% 
+%\begin{macro}{\_l_siunitx_round_int}
+%\begin{macro}{\_l_siunitx_round_tl}
+%\begin{macro}{\_l_siunitx_round_bool}
+%\begin{macro}{\_l_siunitx_round_decimal_in_tl}
+%\begin{macro}{\_l_siunitx_round_decimal_out_tl}
+%\begin{macro}{\_l_siunitx_round_integer_in_tl}
+%\begin{macro}{\_l_siunitx_round_integer_out_tl}
+% The rounding system needs a number of variables.
 %    \begin{macrocode}
-\newcommand*{\si@fix@thin}{\,}
-\newcommand*{\si@fix@med}{\:}
-\newcommand*{\si@fix@medium}{\:}
-\newcommand*{\si@fix@thick}{\;}
-\newcommand*{\si@fix@space}{\text{ }}
+\int_new:N \_l_siunitx_round_int
+\tl_new:N \_l_siunitx_round_tl
+\bool_new:N \_l_siunitx_round_bool
+\tl_new:N \_l_siunitx_round_decimal_in_tl
+\tl_new:N \_l_siunitx_round_decimal_out_tl
+\tl_new:N \_l_siunitx_round_integer_in_tl
+\tl_new:N \_l_siunitx_round_integer_out_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@fix@cdot}
-%\begin{macro}{\si@fix@comma}
-%\begin{macro}{\si@fix@stop}
-%\begin{macro}{\si@fix@fullstop}
-%\begin{macro}{\si@fix@period}
-%\begin{macro}{\si@fix@times}
-%\begin{macro}{\si@fix@tighttimes}
-%\begin{macro}{\si@fix@tightcdot}
-% Next there are macros for material that is not simply whitespace.
-% To allow several options, the full-stop gets lots of names.
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_process_decimal_int}
+%\begin{macro}{\_l_siunitx_process_uncertainty_int}
+%\begin{macro}{\_l_siunitx_uncertainty_decimal_tl}
+%\begin{macro}{\_l_siunitx_uncertainty_integer_tl}
+% The code to expand uncertainties needs to know numbers of digits, and
+% to store various data.
 %    \begin{macrocode}
-\newcommand*{\si@fix@cdot}{{}\cdot{}}
-\newcommand*{\si@fix@comma}{{,}}
-\newcommand*{\si@fix@stop}{{.}}
-\newcommand*{\si@fix@fullstop}{{.}}
-\newcommand*{\si@fix@period}{{.}}
-\newcommand*{\si@fix@times}{\times}
-\newcommand*{\si@fix@tighttimes}{\bgroup\times\egroup}
-\newcommand*{\si@fix@tightcdot}{\bgroup\cdot\egroup}
+\int_new:N \_l_siunitx_process_decimal_int
+\int_new:N \_l_siunitx_process_uncertainty_int
+\tl_new:N \_l_siunitx_uncertainty_decimal_tl
+\tl_new:N \_l_siunitx_uncertainty_integer_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_process_decimal_zero_bool}
+%\begin{macro}{\_l_siunitx_process_integer_zero_bool}
+%\begin{macro}{\_l_siunitx_process_sign_tl}
+%\begin{macro}{\_l_siunitx_process_plus_tl}
+%\begin{macro}{\_l_siunitx_unity_mantissa_tl}
+%\begin{macro}{\_l_siunitx_process_zero_exponent_bool}
+%\begin{macro}{\_l_siunitx_process_precision_int}
+% First, the options are set up.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  add-decimal-zero  .bool_set:N = \_l_siunitx_process_decimal_zero_bool,
+  add-integer-zero  .bool_set:N = \_l_siunitx_process_integer_zero_bool,
+  explicit-sign     .tl_set:N   = \_l_siunitx_process_sign_tl,
+  retain-explicit-plus  .bool_set:N = \_l_siunitx_process_plus_tl,
+  retain-unity-mantissa .bool_set:N = 
+    \_l_siunitx_process_unity_mantissa_bool,
+  retain-zero-exponent .bool_set:N =
+    \_l_siunitx_process_zero_exponent_bool,
+  round-mode        .choice: ,
+  round-mode / figures .code:n = 
+    { \tl_set:Nn \_l_siunitx_round_tl { figures } },
+  round-mode / off     .code:n = { \tl_clear:N \_l_siunitx_round_tl },
+  round-mode / places  .code:n = 
+    { \tl_set:Nn \_l_siunitx_round_tl { places } },
+  round-precision      .int_set:N = \_l_siunitx_process_precision_int,
+}
+\keys_set:nn { siunitx } {
+  add-decimal-zero      = true,
+  add-integer-zero      = true,
+  retain-unity-mantissa = true, 
+  round-precision       = 2,
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@fix@plus}
-%\begin{macro}{\si@fix@minus}
-%\begin{macro}{\si@fix@pm}
-%\begin{macro}{\si@fix@tightpm}
-%\begin{macro}{\si@fix@mp}
-% Signs for numbers are needed.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_process:}
+% Post-processing is a series of small tasks.
 %    \begin{macrocode}
-\newcommand*{\si@fix@plus}{+}
-\newcommand*{\si@fix@minus}{-}
-\newcommand*{\si@fix@pm}{\pm}
-\newcommand*{\si@fix@tightpm}{\bgroup\pm\egroup}
-\newcommand*{\si@fix@mp}{\mp}
+\cs_set_protected_nopar:Npn \_siunitx_number_process: {
+  \_siunitx_number_process_sign:
+  \_siunitx_number_process_zero_fill:
+  \_siunitx_number_process_mantissa:
+  \prop_if_in:NnF \_l_siunitx_number_in_prop { symbolic } 
+    {
+      \_siunitx_number_process_exponent:
+      \_siunitx_number_process_uncertainty:
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { uncertainty }
+        { \_siunitx_number_process_round: }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_process_exponent:}
+%\begin{macro}[aux]{\_siunitx_number_process_exponent_aux:n}
+% To check for a totally zero exponent, the possibility that one or more
+% of the exponent storage areas is zero needs to be considered. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_exponent: {
+  \bool_if:NF \_l_siunitx_process_zero_exponent_bool 
+    {
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent } 
+        {
+          \bool_set_false:N \_l_siunitx_tmp_bool
+          \_siunitx_number_process_exponent_aux:n { integer }
+          \bool_if:NF \_l_siunitx_tmp_bool
+            { \_siunitx_number_process_exponent_aux:n { decimal } }
+          \bool_if:NF \_l_siunitx_tmp_bool 
+            {
+              \prop_del:Nn \_l_siunitx_number_in_prop { exponent }
+              \prop_del:Nn \_l_siunitx_number_in_prop 
+                { exponent-integer }
+              \prop_del:Nn \_l_siunitx_number_in_prop 
+                { exponent-decimal }
+             }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_exponent_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { exponent- #1 }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl 
+    {
+      \intexpr_compare:nNnF 
+        { \_l_siunitx_tmpa_tl } = { 0 } 
+        { \bool_set_true:N \_l_siunitx_tmp_bool }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_process_figures:n}
+%\begin{macro}[aux]{\_siunitx_number_process_figures_aux:n}
+%\begin{macro}[aux]{\_siunitx_number_process_figures_init:n}
+% Rather than count figures to start with, a completely different 
+% approach is used here.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop {#1} 
+    { \_siunitx_number_process_figures_aux:n {#1} }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_aux:n #1 {
+  \_siunitx_number_process_figures_init:n {#1}
+  \_siunitx_number_process_figures_count:n { integer }
+  \_siunitx_number_process_figures_count:n { decimal }
+  \bool_if:NTF \_l_siunitx_round_bool 
+    {
+      \bool_set_false:N \_l_siunitx_round_bool
+      \intexpr_compare:nNnTF 
+        { \int_use:N \_l_siunitx_round_int } > 
+          { \int_use:N \_l_siunitx_process_precision_int }
+        { 
+          \_siunitx_number_process_figures_round: 
+          \_siunitx_number_process_round_tidy:n {#1}
+        }
+        { \_siunitx_number_process_figures_pad:n {#1} }
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -integer } { 0 }
+      \prop_del:Nn \_l_siunitx_number_in_prop { #1 -decimal }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_init:n #1 {
+  \int_zero:N \_l_siunitx_round_int
+  \bool_set_false:N \_l_siunitx_round_bool
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal } 
+    \_l_siunitx_round_decimal_in_tl
+  \quark_if_no_value:NT \_l_siunitx_round_decimal_in_tl
+    { \tl_clear:N \_l_siunitx_round_decimal_in_tl }  
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer } 
+    \_l_siunitx_round_integer_in_tl
+  \quark_if_no_value:NT \_l_siunitx_round_integer_in_tl
+    { \tl_clear:N \_l_siunitx_round_integer_in_tl }  
+  \tl_clear:N \_l_siunitx_round_decimal_out_tl
+  \tl_clear:N \_l_siunitx_round_integer_out_tl
+}
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@fix@two}
-%\begin{macro}{\si@fix@ten}
-% The literals ``2'' and ``10'' are needed for exponents.
+%\begin{macro}{\_siunitx_number_process_figures_count:n}
+%\begin{macro}[aux]{\_siunitx_number_process_figures_count_aux:n}
+% The counting code has to check that characters are actually 
+% significant.
 %    \begin{macrocode}
-\newcommand*{\si@fix@two}{2}
-\newcommand*{\si@fix@ten}{10}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_figures_count:n #1 {
+  \tl_if_empty:cF { _l_siunitx_round_ #1 _in_tl } 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -uncertainty } 
+        { \_siunitx_number_process_figures_count_aux:n {#1} }
+    }
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_figures_count_aux:n #1 {
+  \int_set:Nn \_l_siunitx_tmp_int 
+    { \exp_args:Nv \tl_head_i:n { _l_siunitx_round_ #1 _in_tl } }
+  \tl_set:cx { _l_siunitx_round_ #1 _in_tl } 
+    { \exp_args:Nv \tl_tail:n { _l_siunitx_round_ #1 _in_tl } }
+  \tl_put_left:cV { _l_siunitx_round_ #1 _out_tl } \_l_siunitx_tmp_int
+  \bool_if:NF \_l_siunitx_round_bool 
+    {
+      \intexpr_compare:nNnF 
+        { \_l_siunitx_tmp_int } = { 0 }
+        { \bool_set_true:N \_l_siunitx_round_bool }
+    }
+  \bool_if:NT \_l_siunitx_round_bool 
+    { \int_incr:N \_l_siunitx_round_int }
+  \tl_if_empty:cTF { _l_siunitx_round_ #1 _in_tl } 
+    {
+      \tl_set_eq:cc { _l_siunitx_round_ #1 _in_tl } 
+        { _l_siunitx_round_ #1 _out_tl }
+      \tl_clear:c { _l_siunitx_round_ #1 _out_tl }
+    }
+    { \_siunitx_number_process_figures_count_aux:n {#1} }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@fix@slash}
-% Another optional component that will probably not be used by many
-% people.
-%    \begin{macrocode}
-\newcommand*{\si@fix@slash}{/}
+%\begin{macro}{\_siunitx_number_process_figures_round:}
+%\begin{macro}[aux]{\_siunitx_number_process_figures_round_loop:}
+% The control macro for rounding to figures does the decimal part
+% then the integer part as loops. There is then some tidying up if a
+% digit is carried at the end.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_round: {
+  \int_set:Nn \_l_siunitx_round_int 
+    { \_l_siunitx_round_int - \_l_siunitx_process_precision_int }
+  \tl_if_empty:NF \_l_siunitx_round_decimal_in_tl 
+    { \_siunitx_number_process_figures_round_loop: }
+  \tl_if_empty:NF \_l_siunitx_round_integer_in_tl 
+    { \_siunitx_number_process_figures_integer: }
+  \bool_if:NT \_l_siunitx_round_bool 
+    {
+      \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 1 }
+      \tl_if_empty:NF \_l_siunitx_round_decimal_out_tl 
+        {
+          \tl_reverse:N \_l_siunitx_round_decimal_out_tl
+          \tl_set:Nx \_l_siunitx_round_decimal_out_tl 
+            { \tl_tail:n \_l_siunitx_round_decimal_out_tl }
+          \tl_reverse:N \_l_siunitx_round_decimal_out_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_figures_round_loop: {
+  \_siunitx_number_process_round_decimal:
+  \tl_if_empty:NF \_l_siunitx_round_decimal_in_tl 
+    { \_siunitx_number_process_figures_round_loop: }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@fix@none}
-% Finally for spacing, there is the possibility of nothing at all
-%    \begin{macrocode}
-\newcommand*{\si@fix@none}{}
+%\end{macro}
+%\begin{macro}{\_siunitx_number_process_figures_integer:}
+% For figures, the integer part is a little complicated as zeros need
+% to be included.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_integer: {
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_round_int } > { 0 } 
+    {  \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 0 } }
+  \intexpr_compare:nNnF 
+    { \int_use:N \_l_siunitx_round_int } > { 1 } 
+    {
+      \int_set:Nn \_l_siunitx_tmp_int 
+        { \exp_args:NV \tl_head_i:n \_l_siunitx_round_integer_in_tl }
+      \bool_if:NT \_l_siunitx_round_bool
+        { \int_incr:N \_l_siunitx_tmp_int }
+      \bool_set_false:N \_l_siunitx_round_bool
+      \intexpr_compare:nNnTF 
+        { \int_use:N \_l_siunitx_round_int } = { 1 }
+        {
+          \intexpr_compare:nNnT 
+            { \int_use:N \_l_siunitx_tmp_int } > { 4 }
+            { \bool_set_true:N \_l_siunitx_round_bool }
+        }
+        {
+          \intexpr_compare:nNnT 
+            { \int_use:N \_l_siunitx_tmp_int } > { 10 } 
+            {
+              \bool_set_true:N \_l_siunitx_round_bool
+              \int_zero:N \_l_siunitx_tmp_int
+            }
+          \tl_put_left:NV \_l_siunitx_round_integer_out_tl 
+            \_l_siunitx_tmp_int
+        }
+    }   
+  \int_decr:N \_l_siunitx_round_int
+  \tl_set:Nx \_l_siunitx_round_integer_in_tl 
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_integer_in_tl }
+  \tl_if_empty:NF \_l_siunitx_round_integer_in_tl 
+    { \_siunitx_number_process_figures_integer: }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@fix@to}
-%\begin{macro}{\si@fix@dash}
-%\begin{macro}{\si@fix@dots}
-% For the range system.
+%\begin{macro}{\_siunitx_number_process_figures_pad:n}
+% If the number is too short, then the reversal is undone and the 
+% padding routine is called.
 %    \begin{macrocode}
-\newcommand*{\si@fix@to}{ to }
-\newcommand*{\si@fix@dash}{--}
-\newcommand*{\si@fix@dots}{\,\dots\,}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_pad:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_in_tl
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_in_tl
+  \int_set:Nn \_l_siunitx_round_int 
+    { \_l_siunitx_process_precision_int - \_l_siunitx_round_int }
+  \_siunitx_number_process_pad:n {#1}
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_c_siunitx_unity_tl}
+%\begin{macro}{\_siunitx_number_process_mantissa:}
+% A check for the mantissa consisting only of the token \texttt{1}, when
+% an exponent is also available.
+%    \begin{macrocode}
+\tl_new:N \_c_siunitx_unity_tl 
+\tl_set:Nn \_c_siunitx_unity_tl { 1 }
+\cs_set_protected_nopar:Npn \_siunitx_number_process_mantissa: {
+  \bool_if:NF \_l_siunitx_process_unity_mantissa_bool 
+    {
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent } 
+        {
+          \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-integer }
+            \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+            {
+              \tl_if_eq:NNT \_c_siunitx_unity_tl \_l_siunitx_tmpa_tl 
+                { 
+                  \prop_if_in:NnF \_l_siunitx_number_in_prop 
+                    { mantissa-decimal-marker }
+                    {
+                      \prop_del:Nn \_l_siunitx_number_in_prop 
+                        { mantissa }
+                      \prop_del:Nn \_l_siunitx_number_in_prop 
+                        { mantissa-integer }
+                    }    
+                }
+            }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %
-%\subsection{Symbols}
-%\begin{macro}{\si@symbol}
-% Each of the symbol macros needs to be set up; the options give a
-% maths and text mode sign, but internally a single macro is needed
-% for each.
-%    \begin{macrocode}
-\newcommand*{\si@symbol}[1]{%
-  \expandafter\protected\expandafter\def
-    \csname si@sym@#1\endcsname{%
-    \ifmmode
-      \expandafter\csname si@maths#1\expandafter\endcsname
-    \else
-      \expandafter\csname si@text#1\expandafter\endcsname
-    \fi}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@sym@Omega}
-%\begin{macro}{\si@sym@ringA}
-%\begin{macro}{\si@sym@mu}
-%\begin{macro}{\si@sym@degree}
-%\begin{macro}{\si@sym@minute}
-%\begin{macro}{\si@sym@second}
-%\begin{macro}{\si@sym@celsius}
-% The various symbols are now declared.
-%    \begin{macrocode}
-\si@symbol{Omega}
-\si@symbol{ringA}
-\si@symbol{mu}
-\si@symbol{degree}
-\si@symbol{minute}
-\si@symbol{second}
-\si@symbol{celsius}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% The issue of redefinition of symbols now arises.  \currpkg can
-% check for the loading of a number of support package, and can then
-% redefine the appropriate symbols.
-%    \begin{macrocode}
-\AtBeginDocument{%
-  \ifsi@redefsymbols
-    \@ifpackageloaded{textcomp}
-      {\si@log@debug{Redefining symbols using textcomp}%
-       \renewcommand*{\si@textdegree}{\textdegree}%
-       \renewcommand*{\si@mathsdegree}{\text{\textdegree}}%
-%    \end{macrocode}
-% \pkg{mathptmx} will give issues with \pkg{textcomp} and the
-% \si{\ohm} sign.
-%    \begin{macrocode}
-       \@ifpackageloaded{mathptmx}{}
-         {\renewcommand*{\si@textmu}{\textmu}%
-          \renewcommand*{\si@textOmega}{\textohm}}%
-%    \end{macrocode}
-% The \si{\angstrom} symbol is only redefined if the encoding is
-% OT1; other encodings should have a proper glyph used for \cs{AA}.
-% The \cs{encodingdefault} macro is \cs{long} for some reason.
-%    \begin{macrocode}
-       \renewcommand*{\si@tempa}{OT1}%
-       \ifx\si@tempa\encodingdefault
-         \renewcommand*{\si@mathsringA}{%
-           \text{\capitalring{A}}}%
-         \renewcommand*{\si@textringA}{\capitalring{A}}
-       \fi}{}
-    \@ifpackageloaded{upgreek}
-      {\si@log@debug{Redefining symbols using upgreek}%
-       \renewcommand*{\si@mathsOmega}{\Upomega}}{}
-  \fi}
-%    \end{macrocode}
-%
-%\subsection{Handling fractions}
-%\begin{macro}{\si@frac}
-%\begin{macro}{\si@frc@hook}
-%\begin{macro}{\si@frc@frac}
-%\begin{macro}{\si@frc@slash}
-%\begin{macro}{\si@frc@nice}
-%\begin{macro}{\si@frc@sfrac}
-% Various methods of handling fractions are provided.
-%    \begin{macrocode}
-\newcommand*{\si@frc@frac}[2]{%
-  \ensuremath{\si@frc@hook\frac{%
-    \expandafter\si@unt@out\expandafter{#1}}%
-    {\expandafter\si@unt@out\expandafter{#2}}}}
-\let\si@frac\si@frc@frac
-\newcommand*{\si@frc@hook}{}
-\newcommand*{\si@frc@slash}[2]{%
-    \expandafter\si@unt@out\expandafter{#1}%
-    \si@out{\ensuremath{\si@slash}}%
-    \expandafter\si@unt@out\expandafter{#2}}
-\newcommand*{\si@frc@nice}[2]{%
-  \ensuremath{\si@frc@nicefrac{\expandafter\si@unt@out%
-    \expandafter{#1}}{\expandafter\si@unt@out\expandafter
-      {#2}}}}
-\newcommand*{\si@frc@sfrac}[2]{%
-    \sfrac{\expandafter\si@unt@out\expandafter{#1}}%
-      {\expandafter\si@unt@out\expandafter{#2}}}
-\AtBeginDocument{
-  \@ifpackageloaded{xfrac}
-    {}
-    {\si@log@inf{xfrac package unavailable\MessageBreak
-       using `fraction=sfrac' will fall back on\MessageBreak
-       nicefrac-like method}%
-     \renewcommand*{\si@frc@sfrac}[2]{%
-      \si@log@warn{xfrac package unavailable}%
-      \si@frc@nice{#1}{#2}}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@frc@nicefrac}
-%\begin{macro}{\si@frc@displen}
-%\begin{macro}{\si@frc@textlen}
-%\begin{macro}{\si@frc@suplen}
-%\begin{macro}{\si@frc@ssuplen}
-% To avoid needing \units installed, the \cs{nicefrac} macro needs
-% to be emulated here. The code is taken (with permission) from
-% \kg{nicefrac}.\footnote{The original is licensed under the GPL;
-% thanks to the author Axel Reichert for permission to copy the code
-% here.}
-%    \begin{macrocode}
-\newlength\si@frc@displen
-\newlength\si@frc@textlen
-\newlength\si@frc@suplen
-\newlength\si@frc@ssuplen
-\newcommand*{\si@frc@nicefrac}{%
-  \ifmmode
-    \expandafter\si@frc@mathsnf
-  \else
-    \expandafter\si@frc@textnf
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@frc@mathsnf}
-%\darg{numerator}
-%\darg{denominator}
-% The maths mode system.
-%    \begin{macrocode}
-\newcommand*{\si@frc@mathsnf}[2]{%
-  \begingroup
-    \settoheight{\si@frc@displen}{\ensuremath{%
-      \displaystyle{M}}}%
-    \settoheight{\si@frc@textlen}{\ensuremath{%
-      \textstyle{M}}}%
-    \settoheight{\si@frc@suplen}{\ensuremath{%
-      \scriptstyle{M}}}%
-    \settoheight{\si@frc@ssuplen}{%
-      \ensuremath{\scriptscriptstyle{M}}}%
-    \addtolength{\si@frc@displen}{-\si@frc@ssuplen}%
-    \addtolength{\si@frc@textlen}{-\si@frc@ssuplen}%
-    \addtolength{\si@frc@suplen}{-\si@frc@ssuplen}%
-    \mathchoice
-      {\raisebox{\si@frc@displen}{\ensuremath{%
-        \scriptstyle{#1}}}}%
-      {\raisebox{\si@frc@textlen}{\ensuremath{%
-         \scriptstyle{#1}}}}%
-      {\raisebox{\si@frc@suplen}%
-        {\ensuremath{\scriptscriptstyle{#1}}}}%
-      {\raisebox{\si@frc@ssuplen}%
-        {\ensuremath{\scriptscriptstyle{#1}}}}%
-    \mkern-2mu\relax/\mkern-1mu\relax
-    \bgroup
-      \mathchoice
-        {\scriptstyle}%
-        {\scriptstyle}%
-        {\scriptscriptstyle}%
-        {\scriptscriptstyle}%
-      {#2}%
-    \egroup
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@frc@textnf}
-%\darg{numerator}
-%\darg{denominator}
-% A stripped down version of the \pkg{nicefrac} system for text mode.
-%    \begin{macrocode}
-\newcommand*{\si@frc@textnf}[2]{%
-  \begingroup
-    \settoheight{\si@frc@textlen}{M}%
-    \settoheight{\si@frc@ssuplen}{\fontsize\sf@size\z@\relax
-      \selectfont{M}}%
-    \addtolength{\si@frc@textlen}{-\si@frc@ssuplen}%
-    \raisebox{\si@frc@textlen}{\fontsize\sf@size\z@\relax
-      \selectfont{#1}}%
-    \hspace{-0.25ex}/\hspace{-0.25ex}%
-    \hbox{\fontsize\sf@size\z@\selectfont{#2}}%
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@frc@ugly}
-%\darg{numerator}
-% The \cs{si@frc@ugly} macro is needed to emulate the \opt{ugly}
-% option in \units, where output depends on the current mode.
-%    \begin{macrocode}
-\newcommand*{\si@frc@ugly}[1]{%
-  \renewcommand*{\si@tempa}{#1}%
-  \ifmmode
-    \expandafter\si@frc@frac
-  \else
-    \renewcommand*{\si@tempb}{1}%
-    \ifx\si@tempa\si@tempb
-%    \end{macrocode}
-% The slash switch cannot be used, so the possibility of the
-% numerator being one is handled here.
-%    \begin{macrocode}
-      \setbox\si@tempboxa=\hbox{\ensuremath{\si@valuesep}}%
-      \hskip-\wd\si@tempboxa\relax
-      \renewcommand*{\si@tempa}{}%
-    \fi
-    \expandafter\si@frc@slash
-  \fi
-  {\si@tempa}}
-%    \end{macrocode}
-%\end{macro}
-%
-%\subsection{Font control}
-% A number of controls and tests are needed to control the font used
-% for output.  Underlying all of this is the \AMS\ package
-% \pkg{amstext} package, providing the \cs{text} command.  Much of
-% the font control system here is taken more or less verbatim from
-% \SIstyle; modifications have been made to fit the \currpkg
-% interface.
-%
-%\begin{macro}{\si@fam@sf}
-%\begin{macro}{\si@fam@tt}
-% The package needs to know the maths font families in use.  This is
-% set right at the start of the document, after any changes can have
-% been made by, for example, \pkg{fontspec}.
-%    \begin{macrocode}
-\g@addto@macro{\document}{%
-  \ifdefined\mathsf
-    \setbox\si@tempboxa=\hbox{%
-      $\mathsf{\global\chardef\si@fam@sf=\fam}$}%
-  \else
-    \si@log@inf{\string\mathsf not found}%
-    \global\chardef\si@fam@sf=99\relax
-  \fi
-  \ifdefined\mathtt
-    \setbox\si@tempboxa=\hbox{%
-      $\mathtt{\global\chardef\si@fam@tt=\fam}$}%
-  \else
-    \si@log@inf{\string\mathtt not found}%
-    \global\chardef\si@fam@tt=99\relax
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%
-%\begin{macro}{\si@fam@detect@default}
-%\changes{v1.4}{2010/01/16}{Detect entire document in non-serif font}
-%\changes{v1.4c}{2010/02/22}{Better testing}
-% Some packages (for example \pkg{cmbright}) and classes
-% (for example \pkg{beamer}) set the default family to be something
-% other than serif family. A one-off detection will make life easier
-% all round.
+%\begin{macro}{\_siunitx_number_process_pad:n}
+% For padding a number by adding zero to the end repeatedly. This can
+% happen if the input was zero or if the number is too short.
 %    \begin{macrocode}
-\newcommand*\si@fam@detect@default{%
-  \edef\si@tempa{\familydefault}%
-  \edef\si@tempb{\sfdefault}%
-  \ifx\si@tempa\si@tempb
-    \@ifpackageloaded{cmbright}{}{\sisetup{ mathsrm = mathsf}}%
-    \sisetup{ textrm = sffamily }%
-  \fi
-  \edef\si@tempb{\ttdefault}%
-  \ifx\si@tempa\si@tempb
-    \sisetup
-      {
-        mathsrm = mathtt,
-        textrm  = ttfamily
-      }%
-  \fi
+\cs_set_protected_nopar:Npn \_siunitx_number_process_pad:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal } 
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \intexpr_while_do:nNnn
+        { \int_use:N \_l_siunitx_round_int } > { 0 } 
+        {
+          \tl_put_right:Nn \_l_siunitx_tmpa_tl { 0 }
+          \int_decr:N \_l_siunitx_round_int
+        }
+      \prop_put:NnV \_l_siunitx_number_in_prop { #1 -decimal } 
+        \_l_siunitx_tmpa_tl
+    }
 }
-\AtBeginDocument{\si@fam@detect@default}
 %    \end{macrocode}
 %\end{macro}
 %
-%\begin{macro}{\si@fam@ifbtext}
-%\begin{macro}{\si@fam@ifbmaths}
-%\darg{code}
-% These tests check for bold in text and maths mode, respectively.
+%\begin{macro}{\_siunitx_number_process_places:n}
+%\begin{macro}[aux]{\_siunitx_number_process_places_aux_i:n}
+% For rounding to a fixed number of places, a check is made to see if
+% the decimal part is exactly zero. If it is, just create the
+% appropriate number of zeros in the padding routine.  Otherwise, do the
+% real work.
 %    \begin{macrocode}
-\newcommand*{\si@fam@ifbtext}[1]{%
-  \if b\expandafter\@car\f@series\@nil
-    #1\fi}
-\newcommand*{\si@fam@ifbmaths}[1]{%
-  \renewcommand*{\si@tempa}{bold}%
-  \ifx\math@version\si@tempa
-    #1\fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@fam@ifbinline}
-% For compatibility with \units, a method to change the behaviour
-% when in inline maths is needed for the bold detector.
-%    \begin{macrocode}
-\newcommand*{\si@fam@ifbinline}{%
-  \ifsi@inlinebtext
-    \expandafter\si@fam@ifbtext
-  \else
-    \expandafter\si@fam@ifbmaths
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@fam@ifitext}
-%\darg{code}
-% This test check for italic or slanted text in text mode, by
-% negation (upright text is |n|).
-%    \begin{macrocode}
-\newcommand*{\si@fam@ifitext}[1]{%
-  \if n\expandafter\@car\f@series\@nil\else
-    #1\fi}
-%    \end{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop {#1} 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -uncertainty } 
+        { \_siunitx_number_process_places_aux_i:n {#1} }
+    }
+}  
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_aux_i:n #1 {
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_process_precision_int } = { 0 } 
+    { \prop_del:Nn \_l_siunitx_number_in_prop { #1 -decimal } }
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \tl_if_empty:NT \_l_siunitx_tmpa_tl 
+            { \tl_set:Nn \_l_siunitx_tmpa_tl { 0 } }
+          \intexpr_compare:nNnTF 
+            { \_l_siunitx_tmpa_tl } = { 0 } 
+            {
+              \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -decimal }
+                { }
+              \int_set:Nn \_l_siunitx_round_int 
+                { \_l_siunitx_process_precision_int }
+              \_siunitx_number_process_pad:n {#1}
+            }
+            {
+              \int_set:Nn \_l_siunitx_round_int 
+                { \tl_elt_count:N \_l_siunitx_tmpa_tl }
+              \_siunitx_number_process_places_aux_ii:n {#1}
+            }
+        }
+    }
+}
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
-%\begin{macro}{\si@fam@mode}
-% Detection of the current mode needs to happen``early'' (before any
-% change of \cs{ensuremath}).  So a short macro is provided to do the
-% job.
+%\begin{macro}[aux]{\_siunitx_number_process_places_aux_ii:n}
+% For rounding to a fixed number of places, the package finds the
+% difference in length between what is present and what is required.
+% If the number is too short, there is some simple padding to do.
 %    \begin{macrocode}
-\newcommand*{\si@fam@mode}{%
-  \ifsi@obeymode
-    \ifmmode
-      \sisetup{mode=maths}%
-    \else
-      \sisetup{mode=text}%
-    \fi
-  \fi}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_places_aux_ii:n #1 {
+  \int_sub:Nn \_l_siunitx_round_int 
+    { \_l_siunitx_process_precision_int }
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_round_int } < { 0 } 
+    {
+      \int_set:Nn \_l_siunitx_round_int { - \_l_siunitx_round_int }
+      \_siunitx_number_process_pad:n {#1}
+    }
+    {
+      \_siunitx_number_process_places_init:n {#1}
+      \_siunitx_number_process_places_loop:n {#1}
+      \_siunitx_number_process_round_tidy:n {#1}
+    }
+}
+%    \end{macrocode}
+%\end{macro}
+%\begin{macro}{\_siunitx_number_process_places_init:n}
+% To keep the code a little clearer.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_init:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_in_tl    
+  \quark_if_no_value:NT \_l_siunitx_round_integer_in_tl
+    { \tl_clear:N \_l_siunitx_round_integer_in_tl }
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_in_tl
+  \tl_reverse:N \_l_siunitx_round_integer_in_tl
+  \tl_reverse:N \_l_siunitx_round_decimal_in_tl
+  \tl_clear:N \_l_siunitx_round_integer_out_tl
+  \tl_clear:N \_l_siunitx_round_decimal_out_tl
+  \bool_set_false:N \_l_siunitx_round_bool
+}
+%    \end{macrocode}
+%\end{macro}
+%\begin{macro}[aux]{\_siunitx_number_process_places_loop:n}
+% If there is a decimal, do the decimal processing then come back here.
+% If there is an integer, do the same. Only if both are empty does the
+% loop stop.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_loop:n #1 {
+  \tl_if_empty:NTF \_l_siunitx_round_decimal_in_tl 
+    {
+      \tl_if_empty:NF \_l_siunitx_round_integer_in_tl 
+        {
+          \_siunitx_number_process_places_integer:n {#1}
+          \_siunitx_number_process_places_loop:n {#1}
+        }
+      \bool_if:NT \_l_siunitx_round_bool 
+        {
+          \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 1 }
+          \bool_set_false:N \_l_siunitx_round_bool
+        }
+    }
+    {
+      \_siunitx_number_process_round_decimal:
+      \_siunitx_number_process_places_loop:n {#1}
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@fam@colourcmd}
-% The colour command is set up.
-%    \begin{macrocode}
-\AtBeginDocument{
-  \@ifpackageloaded{color}
-    {\let\si@fam@colourcmd\color}
-    {\let\si@fam@colourcmd\@gobble}}
+%\begin{macro}[aux]{\_siunitx_number_process_places_integer:n}
+% Rounding for integers is just a case of carrying digits.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_places_integer:n #1 {
+  \int_set:Nn \_l_siunitx_tmp_int 
+    { \exp_args:NV \tl_head_i:n \_l_siunitx_round_integer_in_tl }
+  \tl_set:Nx \_l_siunitx_round_integer_in_tl 
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_integer_in_tl }
+  \bool_if:NT \_l_siunitx_round_bool
+    { \int_incr:N \_l_siunitx_tmp_int }
+  \bool_set_false:N \_l_siunitx_round_bool
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_tmp_int } = { 10 } 
+    {
+      \int_zero:N \_l_siunitx_tmp_int
+      \bool_set_true:N \_l_siunitx_round_bool 
+    }
+  \tl_put_left:NV \_l_siunitx_round_integer_out_tl \_l_siunitx_tmp_int
+}
 %    \end{macrocode}
 %\end{macro}
 %
-%\begin{macro}{\ifsi@fam@set}
-%\begin{macro}{\ifsi@textmode}
-% A marker is set up to check if font-matching has been taken place.
-% A second flag is used to track the use of text mode.
+%\begin{macro}{\_siunitx_number_process_round:}
+% The lead-off for rounding is the same for decimal places and 
+% significant figures.
 %    \begin{macrocode}
-\newif\ifsi@fam@set
-\newif\ifsi@textmode
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round: {
+  \tl_if_empty:NF \_l_siunitx_round_tl 
+    {
+      \cs_set_nopar:Npx \_siunitx_tmp:w 
+        {
+          \exp_not:N \clist_map_function:nN 
+            { mantissa , complex }
+            \exp_not:c 
+              { _siunitx_number_process_ \_l_siunitx_round_tl :n }
+        }
+      \_siunitx_tmp:w        
+    }
+}
 %    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@fam@set}
-% Using the code from \SIstyle as a base, a set of tests are used to
-% set the current font families and weights.  To begin with, the
-% mode to use is set up.
-%    \begin{macrocode}
-\newcommand*{\si@fam@set}{%
-  \ifsi@out@num
-    \ifsi@numtextmode
-      \expandafter\expandafter\expandafter\si@textmodetrue
-    \else
-      \expandafter\expandafter\expandafter\si@textmodefalse
-    \fi
-  \else
-    \ifsi@unittextmode
-      \expandafter\expandafter\expandafter\si@textmodetrue
-    \else
-      \expandafter\expandafter\expandafter\si@textmodefalse
-    \fi
-  \fi
-%    \end{macrocode}
-%\begin{macro}{\si@mathsrm}
-%\begin{macro}{\si@mathssf}
-%\begin{macro}{\si@mathstt}
-%\begin{macro}{\si@textrm}
-%\begin{macro}{\si@textsf}
-%\begin{macro}{\si@texttt}
-%\begin{macro}{\si@colourcmd}
-%\begin{macro}{\si@colour}
-% The appropriate font macros are now established, if necessary.
-%    \begin{macrocode}
-  \ifsi@fam@set\else
-    \let\si@colourcmd\@gobble
-    \ifsi@out@num
-      \let\si@mathsrm\si@valuemathsrm
-      \let\si@mathssf\si@valuemathssf
-      \let\si@mathstt\si@valuemathstt
-      \let\si@textrm\si@valuetextrm
-      \let\si@textsf\si@valuetextsf
-      \let\si@texttt\si@valuetexttt
-      \ifsi@colourvalues
-        \let\si@colourcmd\si@fam@colourcmd
-      \fi
-      \let\si@colour\si@valuecolour
-    \else
-      \let\si@mathsrm\si@unitmathsrm
-      \let\si@mathssf\si@unitmathssf
-      \let\si@mathstt\si@unitmathstt
-      \let\si@textrm\si@unittextrm
-      \let\si@textsf\si@unittextsf
-      \let\si@texttt\si@unittexttt
-      \ifsi@colourunits
-        \let\si@colourcmd\si@fam@colourcmd
-      \fi
-      \let\si@colour\si@unitcolour
-    \fi
-  \fi
-  \si@fam@settrue
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% The temporary macros are needed for the \cs{ifx} tests, which need to
-% be expanded once.
-%    \begin{macrocode}
-  \edef\si@tempa{\sfdefault}%
-  \edef\si@tempb{\ttdefault}%
-%    \end{macrocode}
-%\begin{macro}{\si@fam@maths}
-%\begin{macro}{\si@fam@text}
-% The surrounding font family is only tested if matching is
-% requested.  First, the defaults are set up assuming no detection
-% takes place.
-%    \begin{macrocode}
-  \expandafter\let\expandafter\si@fam@maths
-    \csname\si@mathsrm\endcsname
-  \expandafter\let\expandafter\si@fam@text
-    \csname\si@textrm\endcsname
-  \ifsi@obeyfamily
-    \si@log@debug{Font detection: checking font}%
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% The detection code has to check the mode currently in operation.
-% Display mathematics can be handled in two ways, so this means some
-% code is repeated: it is spun out to separate routines.
-%    \begin{macrocode}
-    \ifmmode
-      \ifinner
-        \si@log@debug{Font detection: inline maths}%
-        \si@fam@dettext
-      \else
-        \si@log@debug{Font detection: display maths}%
-        \ifsi@detectdisplay
-          \si@fam@detmaths
-        \else
-          \si@fam@dettext
-        \fi
-      \fi
-    \else
-      \si@log@debug{Font detection: text}%
-      \si@fam@dettext
-    \fi
-  \else
-    \si@log@debug{Font detection: inactive}%
-  \fi
-%    \end{macrocode}
-%\begin{macro}{\si@fam@bold}
-% With the font family set, the next check is for bold text.  This
-% again needs to examine the current mode. Things are a bit more
-% complex than in \SIstyle as it is possible to be typesetting in
-% either text or maths mode.  The bold command is set up with
-% \cs{def}, as nested calls can occur.
-%    \begin{macrocode}
-  \def\si@fam@bold{\unboldmath\mdseries}%
-  \ifsi@obeybold
-    \si@log@debug{Weight detection: checking weight}%
-    \ifmmode
-      \ifdim\displaywidth>0pt\relax
-        \ifsi@detectdisplay
-          \expandafter\si@fam@ifbmaths
-        \else
-          \expandafter\si@fam@ifbtext
-        \fi
-        \si@fam@setbold
-      \else
-        \si@fam@ifbinline\si@fam@setbold
-      \fi
-    \else
-      \si@fam@ifbtext\si@fam@setbold
-    \fi
-  \fi
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@fam@italic}
-% The value of \opt{obeyitalic} is now tested; as this does nothing
-% in maths mode, a reminder is added to the log.
-%    \begin{macrocode}
-  \let\si@fam@italic\upshape
-  \ifsi@obeyitalic
-    \si@log@debug{Italic detection: checking italic}%
-    \si@fam@ifitext
-      {\let\si@fam@italic\relax
-       \si@log@debug{Italic detection: italic}}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@fam@detmaths}
-%\begin{macro}{\si@fam@dettext}
-% Two detection macros are needed for maths and text mode. This
-% allows handling of the various combinations without needing too
-% many code lines.
-%    \begin{macrocode}
-\newcommand*{\si@fam@detmaths}{%
-  \ifnum\the\fam=\si@fam@sf
-    \si@log@debug{Font detection: sf}%
-    \expandafter\let\expandafter\si@fam@maths
-      \csname\si@mathssf\endcsname
-    \expandafter\let\expandafter\si@fam@text
-      \csname\si@textsf\endcsname
-  \else
-    \ifnum\the\fam=\si@fam@tt
-      \si@log@debug{Font detection: tt}%
-      \expandafter\let\expandafter\si@fam@maths
-        \csname\si@mathstt\endcsname
-      \expandafter\let\expandafter\si@fam@text
-        \csname\si@texttt\endcsname
-    \else
-      \si@log@debug{Font detection: rm}%
-      \expandafter\let\expandafter\si@fam@maths
-        \csname\si@mathsrm\endcsname
-      \expandafter\let\expandafter\si@fam@text
-        \csname\si@textrm\endcsname
-    \fi
-  \fi}
-\newcommand*{\si@fam@dettext}{%
-  \ifx\f@family\si@tempa
-    \si@log@debug{Font detection: sf}%
-    \expandafter\let\expandafter\si@fam@maths
-      \csname\si@mathssf\endcsname
-    \expandafter\let\expandafter\si@fam@text
-      \csname\si@textsf\endcsname
-  \else
-    \ifx\f@family\si@tempb
-      \si@log@debug{Font detection: tt}%
-      \expandafter\let\expandafter\si@fam@maths
-        \csname\si@mathstt\endcsname
-      \expandafter\let\expandafter\si@fam@text
-        \csname\si@texttt\endcsname
-    \else
-      \si@log@debug{Font detection: rm}%
-      \expandafter\let\expandafter\si@fam@maths
-        \csname\si@mathsrm\endcsname
-      \expandafter\let\expandafter\si@fam@text
-        \csname\si@textrm\endcsname
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@fam@setbold}
-%\begin{macro}{\si@fam@boldify}
-% For setting bold, a couple of control macros are needed.
-%    \begin{macrocode}
-\newcommand*{\si@fam@setbold}{%
-  \si@log@debug{Weight detection: bold weight}%
-  \let\si@fam@bold\si@fam@boldify}
-\newcommand*{\si@fam@boldify}{\boldmath\bfseries}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%
-%\subsection{Formatting numbers}
-%\begin{macro}{\num}
-%\doarg{keyval options}
-%\darg{number}
-% The system used here is modelled on that in \numprint; the
-% input is broken down into single tokens, each one is examined and
-% the result is re-assembled into an output number.  However, various
-% changes have been made to the system used, and so the macros here
-% are not simply renamed copies of those in \numprint.  The user
-% macro \cs{num} sets any local keys, then calls the number
-% formatting macro on the processed number.
-%    \begin{macrocode}
-\si@newrobustcmd*{\num}[2][]{%
-  \begingroup
-    \sisetup{#1}%
-    \si@fam@mode
-    \si@num@intabfalse
-    \si@log@debug{Processing \string\num\space input `#2'}%
-    \expandafter\si@out@num\expandafter{\si@num{#2}}%
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@num@intab}
-% A flag for processing inside a table is needed.
-%    \begin{macrocode}
-\newif\ifsi@num@intab
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num}
-%\darg{number}
-% This is the main processing macro.  Unlike the related macro in
-% \numprint, the output of this macro is not subjected to any font
-% changes.  That is left to one of the \cs{si@out@\ldots} macros.  No
-% grouping is applied here; any call to \cs{si@num} (or any of the
-% sub-macros) must be within a group as the definitions used rely on
-% this.  Grouping is not applied here so that other macros can get
-% the various separated parts of the input.
-%    \begin{macrocode}
-\newcommand*{\si@num}[1]{%
-%    \end{macrocode}
-% The argument of the macro is fully expanded before any processing.
-% By using \cs{scantokens}, any odd problems from packages with
-% active characters can be avoided.
-%    \begin{macrocode}
-  \si@num@fixpm
-  \begingroup
-    \makeatletter
-    \@makeother{\,}%
-    \@makeother{\.}%
-    \@makeother{\+}%
-    \@makeother{\-}%
-    \def~{}%
-    \def\,{}%
-    \catcode`\~=\active\relax
-    \catcode`\^=\active\relax
-    \catcode`\_=12\relax
-    \everyeof{\noexpand}%
-    \endlinechar\m@ne
-    \protected@xdef\si@tempa{\scantokens{#1}}%
-  \endgroup
-%    \end{macrocode}
-% Processing only takes place if there is actually something in the
-% argument.  This is tested once ``hard'' spaces have been stripped
-% out; if there is input other than spaces, the processor first
-% checks the validity of the input, then moves on to format it.
-%    \begin{macrocode}
-  \si@ifnotmtarg{\si@tempa}
-    {\si@num@ifvalid{\si@tempa}
-      {\si@num@format{\si@tempa}}
-%    \end{macrocode}
-% The parser has to bailed-out, and so no further processing of
-% the input is done.  Instead, whatever was passed to the macro is
-% returned as supplied.
-%    \begin{macrocode}
-      {\si@log@err{Invalid character `#1' in numerical input}%
-         {Only characters from the list
-          `\si@numvalid'\MessageBreak should be present in the
-          argument of the \string\num\space  macro\MessageBreak
-         (or derivative such as an `s' column)}%
-       {#1}}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@fixpm}
-%\begin{macro}{\si@num@pm}
-%\begin{macro}{\si@num@mp}
-%\begin{macro}{\pm}
-%\begin{macro}{\mp}
-% With certain packages loaded, there can be issues with \cs{pm} and
-% \cs{mp}.  To avoid this, the \eTeX\ \cs{protected} system is
-% employed; this is only used within local groups.
+%\end{macro}
+%\begin{macro}{\_siunitx_number_process_round_decimal:}
+%\begin{macro}[aux]{\_siunitx_number_process_round_decimal_aux:}
+% The rounding routine for decimals is the same for figures and places,
+% so there is a generalised function here. Unfortunately, it is also 
+% complicated!
 %    \begin{macrocode}
-\newcommand*{\si@num@fixpm}{%
-  \let\si@num@pm\pm
-  \let\si@num@mp\mp
-  \protected\def\pm{\si@num@pm}%
-  \protected\def\mp{\si@num@mp}}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round_decimal: {
+  \intexpr_compare:nNnF 
+    { \int_use:N \_l_siunitx_round_int } > { 1 } 
+    { \_siunitx_number_process_round_decimal_aux: }
+  \tl_set:Nx \_l_siunitx_round_decimal_in_tl 
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_decimal_in_tl }
+
+  \int_decr:N \_l_siunitx_round_int
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_round_decimal_aux: {
+  \int_set:Nn \_l_siunitx_tmp_int 
+    { \exp_args:NV \tl_head_i:n \_l_siunitx_round_decimal_in_tl }
+  \bool_if:NT \_l_siunitx_round_bool 
+    { \int_incr:N \_l_siunitx_tmp_int }
+  \bool_set_false:N \_l_siunitx_round_bool
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_round_int } = { 1 } 
+    {
+      \intexpr_compare:nNnT 
+        { \int_use:N \_l_siunitx_tmp_int } > { 4 } 
+        { \bool_set_true:N \_l_siunitx_round_bool }
+    }
+    {
+      \intexpr_compare:nNnT 
+        { \int_use:N \_l_siunitx_tmp_int } = { 10 } 
+        {
+          \bool_set_true:N \_l_siunitx_round_bool
+          \int_zero:N \_l_siunitx_tmp_int
+        }
+      \tl_put_left:NV \_l_siunitx_round_decimal_out_tl 
+        \_l_siunitx_tmp_int
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@ifvalid}
-%\begin{macro}{\si@num@valid}
-%\darg{chars}
-% Assuming that there is a non-space argument to \cs{si@num}, every
-% character is checked to ensure it is valid in the context, so that
-% further processing can occur without sanity checks.  If the
-% character is valid, recursion occurs.
+%\begin{macro}{\_siunitx_number_process_round_tidy:n}
+% To put data back again.
 %    \begin{macrocode}
-\newcommand*{\si@num@ifvalid}[1]{%
-  \begingroup
-    \si@switchtrue
-    \expandafter\si@num@valid#1\@empty\@empty
-    \ifsi@switch
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@num@valid#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numvalid}
-    {\ifx\@empty#2\@empty\else
-       \si@num@valid#2\@empty\@empty\@empty
-     \fi}
-    {\si@switchfalse}}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round_tidy:n #1 {
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_out_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_out_tl
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_process_sign:}
+% Sorting out signs consists of two parts: retaining a plus if necessary
+% and adding an explicit sign.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign: {
+  \bool_if:NF \_l_siunitx_process_plus_tl 
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa-sign }
+        { \_siunitx_number_process_sign_plus:n { mantissa } }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { complex-sign }
+            { 
+              \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+                { \_siunitx_number_process_sign_plus:n { complex } }
+            } 
+        }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent-sign }
+        { \_siunitx_number_process_sign_plus:n { exponent } }
+    }
+  \tl_if_empty:NF \_l_siunitx_process_sign_tl 
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa }
+        { \_siunitx_number_process_sign_add:n { mantissa } }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { complex }
+            { \_siunitx_number_process_sign_add:n { complex } } 
+        }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        { \_siunitx_number_process_sign_add:n { exponent } }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@num@in}
-%\begin{macro}{\si@num@out}
-%\begin{macro}{\si@num@exp}
-%\begin{macro}{\si@num@expsign}
-%\begin{macro}{\si@num@mant}
-%\begin{macro}{\si@num@mantsign}
-%\begin{macro}{\si@num@err}
-%\begin{macro}{\si@num@xpart}
-%\begin{macro}{\si@num@ambig}
-%\begin{macro}{\si@tab@out}
-%\begin{macro}{\si@tab@expout}
-% Various storage macros are needed.
-%    \begin{macrocode}
-\newcommand*{\si@num@in}{}
-\newcommand*{\si@num@out}{}
-\newcommand*{\si@num@exp}{}
-\newcommand*{\si@num@expsign}{}
-\newcommand*{\si@num@mant}{}
-\newcommand*{\si@num@mantsign}{}
-\newcommand*{\si@num@err}{}
-\newcommand*{\si@num@xpart}{}
-\newcommand*{\si@num@ambig}{}
-\newcommand*{\si@tab@out}{}
-\newcommand*{\si@tab@expout}{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
+%\begin{macro}[aux]{\_siunitx_number_process_sign_add:n}
+% Adding a sign to an existing number needs a couple of to make sure
+% there is a number to add to, and to see if there is a sign already.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign_add:n #1 {
+  \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -sign } 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -had-sign } 
+        {
+          \prop_get:NnN \_l_siunitx_number_in_prop {#1}
+            \_l_siunitx_tmpa_tl
+          \tl_if_empty:NTF \_l_siunitx_tmpa_tl 
+            {
+              \prop_put:NnV \_l_siunitx_number_in_prop { sign } 
+                \_l_siunitx_process_sign_tl 
+            }
+            {
+              \prop_put:NnV \_l_siunitx_number_in_prop { #1 -sign } 
+                \_l_siunitx_process_sign_tl
+            }
+        }    
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_c_siunitx_plus_tl}
+%\begin{macro}[aux]{\_siunitx_number_process_sign_plus:n}
+% Holding onto a plus works very much in the same way as adding a sign:
+% some quick tests and an assignment. Using a pre-defined token list is
+% a speed-related choice: very slightly faster comparison.
+%    \begin{macrocode}
+\tl_new:N \_c_siunitx_plus_tl
+\tl_set:Nn \_c_siunitx_plus_tl { + }
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign_plus:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -sign } 
+    \_l_siunitx_tmpa_tl
+  \tl_if_eq:NNT \_c_siunitx_plus_tl \_l_siunitx_tmpa_tl 
+    { 
+      \prop_del:Nn \_l_siunitx_number_in_prop { #1 -sign } 
+      \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -had-sign } { true }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_process_uncertainty:}
+%\begin{macro}[aux]{\_siunitx_number_process_uncertainty_aux:n}
+% There may be a need to expand uncertainties into a decimal and integer
+% part. This is done here so that the core \texttt{in} code is faster.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_uncertainty: {
+  \clist_map_function:nN { mantissa , complex }
+    \_siunitx_number_process_uncertainty_aux:n  
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_uncertainty_aux:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 -uncertainty } 
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { #1 -decimal-marker } 
+        { \_siunitx_number_process_uncertainty_decimal:n {#1} }
+        { \_siunitx_number_process_uncertainty_integer:n {#1} }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\begin{macro}{\_siunitx_number_process_uncertainty_decimal:n}
+%\begin{macro}[aux]{\_siunitx_number_process_uncertainty_count:nn}
+% To deal with an error in the decimal part, care needs to be taken to
+% correctly pad with zeros and also to allow for the possibility that
+% the error crosses the decimal--integer boundary.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_uncertainty_decimal:n #1 {
+  \_siunitx_number_process_uncertainty_count:nn {#1} { decimal }
+  \_siunitx_number_process_uncertainty_count:nn {#1} { uncertainty }
+  \tl_clear:N \_l_siunitx_uncertainty_decimal_tl
+  \tl_clear:N \_l_siunitx_uncertainty_integer_tl
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_process_uncertainty_int }
+      > { \int_use:N \_l_siunitx_process_decimal_int } 
+    { \_siunitx_number_process_uncertainty_separate: }
+    { \_siunitx_number_process_uncertainty_pad: }
+  \tl_if_empty:NF \_l_siunitx_uncertainty_integer_tl 
+    {
+      \prop_put:NnV \_l_siunitx_number_in_prop 
+        { #1 -uncertainty-integer } 
+        \_l_siunitx_uncertainty_integer_tl
+    } 
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -uncertainty-decimal } 
+    \_l_siunitx_uncertainty_decimal_tl
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal-marker } 
+    \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop 
+    { #1 -uncertainty-decimal-marker } \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_uncertainty_count:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 - #2 } 
+    \_l_siunitx_tmpa_tl
+  \int_set:cn { _l_siunitx_process_ #2 _int } 
+    {  \tl_elt_count:N \_l_siunitx_tmpa_tl }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@num@erropen}
-% A flag is set up for tracking unclosed errors.
-%    \begin{macrocode}
-\newif\ifsi@num@erropen
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@format}
-%\begin{macro}{\si@num@arg}
-%\darg{number}
-% The number processor starts by saving |#1| (odd things happen
-% otherwise).  A hook is also provided to allow modifications by
-% other macros.
-%    \begin{macrocode}
-\newcommand*{\si@num@arg}{}
-\newcommand*{\si@num@format}[1]{%
-  \protected@edef\si@num@arg{#1}%
-  \si@log@debug{Formatting number `\si@num@arg'}%
-%    \end{macrocode}
-%\end{macro}
-% The storage areas are emptied.
-%    \begin{macrocode}
-  \renewcommand*{\si@num@in}{}%
-  \renewcommand*{\si@num@exp}{}%
-  \renewcommand*{\si@num@expsign}{}%
-  \renewcommand*{\si@num@mant}{}%
-  \renewcommand*{\si@num@mantsign}{}%
-  \renewcommand*{\si@num@err}{}%
-  \renewcommand*{\si@num@xpart}{}%
-%    \end{macrocode}
-% Any ``x-part'' is now found, leaving the first number in
-% \cs{si@num@in} and anything else in \cs{si@num@xpart}.
-%    \begin{macrocode}
-  \si@switchfalse
-  \expandafter\si@num@findxpart\si@num@arg\@empty\@empty
-%    \end{macrocode}
-% The input is split into an mantissa and an exponent; the flag is
-% used here to indicate if an exponent is found.  The mantissa will
-% end up in \cs{si@num@mant}, and the exponent in \cs{si@num@exp}.
-%    \begin{macrocode}
-  \si@switchfalse
-  \si@num@sepmantexp{\si@num@in}%
-%    \end{macrocode}
-% The sign and value of the mantissa and exponent are separated; the
-% mantissa is done after the exponent as this makes life easier when
-% using the table-formatting fork. Checks are then needed, as a sign
-% with no value is potentially-valid for the mantissa (for example
-% \num{-e10}).
-%    \begin{macrocode}
-  \si@num@sepsign{exp}%
-  \si@num@sepsign{mant}%
-  \ifx\@empty\si@num@exp\@empty
-    \ifx\@empty\si@num@expsign\@empty\else
-      \si@log@warn{Sign but no number for `\si@num@arg'}%
-    \fi
-    \let\si@num@expsign\@empty
-  \fi
-  \ifx\@empty\si@num@mant\@empty
-    \ifx\@empty\si@num@mantsign\@empty\else
-      \ifx\@empty\si@num@exp\@empty
-        \si@log@warn{Sign but no number for `\si@num@arg'}%
-        \let\si@num@mantsign\@empty
-      \fi
-    \fi
-  \fi
-%    \end{macrocode}
-% A check for negative mantissa values is made, to allow some
-% colour-based trickery.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{{-}}%
-  \ifx\si@num@mantsign\si@tempa
-    \ifsi@colourneg
-      \expandafter\expandafter\expandafter\si@fam@colourcmd
-    \else
-      \expandafter\expandafter\expandafter\@gobble
-    \fi
-  \else
-    \expandafter\@gobble
-  \fi
-  {\si@negcolour}%
-%    \end{macrocode}
-% The next stage is to process the remaining data, to find the
-% decimal marker and reformat correctly.  These two macros control
-% this entire process.  The exponent is processed first as this makes
-% life easier when the system is used to typeset tabular
-% material.\footnote{The contents of \cs{si@num@predec} and
-% \cs{si@num@postdec} are needed for the mantissa.}
-%    \begin{macrocode}
-  \si@num@procnum{exp}%
-  \si@num@procnum{mant}%
-%    \end{macrocode}
-% If the exponent is zero, then if might need to be deleted.
-%    \begin{macrocode}
-  \si@str@ifonlychrs{\si@num@exp}{0\si@numdecimal}
-    {\ifsi@allowzeroexp\else
-       \renewcommand*{\si@num@exp}{}%
-       \ifx\@empty\si@num@mant\@empty
-         \renewcommand*{\si@num@mant}{1}%
-       \fi
-     \fi}{}%
-%    \end{macrocode}
-% To build up the number for typesetting, a rather complex series
-% of tests is needed.  First, the ``ambiguous error'' flag is
-% set if there is an exponent and the package has been asked to check
-% this.  The same flag will already be true if a unit is present and
-% checking is active.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@exp\@empty\else
-    \ifsi@trapambigerr
-      \expandafter\expandafter\expandafter\si@num@ambigerrtrue
-    \fi
-  \fi
-%    \end{macrocode}
-%\begin{macro}{\si@num@out}
-%\begin{macro}{\si@tab@out}
-%\begin{macro}{\si@tab@expout}
-% Processing now divides, as when used with the |S| column some extra
-% steps are needed.  Inside a table, the macro \cs{si@tab@out} holds
-% the part of the mantissa before the decimal sign.  The post-decimal
-% part then ends up in \cs{si@num@out}.  On the other hand, under
-% normal circumstances the entire mantissa should be copied to
-% \cs{si@num@out}.
-%    \begin{macrocode}
-  \protected@edef\si@num@out{%
-    \ensuremath{{\si@num@mantsign}}\si@num@mant}%
-  \renewcommand*{\si@tempa}{num}%
-  \ifsi@num@intab
-    \protected@edef\si@tab@out{%
-      \ensuremath{{\si@num@mantsign}}\si@num@predec}%
-    \protected@edef\si@num@out{\si@num@postdec}%
-    \renewcommand*{\si@tempa}{tab}%
-  \fi
-%    \end{macrocode}
-% Now there is the error part to handle.  For tables, a check has to
-% be made so the error ends up in the correct part of the number. The
-% value of \cs{si@tempa} is used to track this., and so is set up
-% here.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@postdec\@empty\else
-    \renewcommand*{\si@tempa}{num}%
-  \fi
-  \ifx\@empty\si@num@err\@empty\else
-%    \end{macrocode}
-% If there is an error, and it is begin separated, the problem arises
-% of the potential for ambiguous values.  This can only apply outside
-% of a table, as \opt{seperr} is disabled in tabular material.
-%    \begin{macrocode}
-    \ifsi@seperr
-      \ifsi@num@ambigerr
-        \protected@edef\si@num@out{%
-          \ensuremath{\si@openerr}\si@num@out}%
-        \si@repeatunitsfalse
-        \expandafter\si@num@erropentrue
-      \else
-%    \end{macrocode}
-% If there is an exponential part and an error, errors are being
-% separated and ambiguous errors are not trapped, then there is work
-% to do.  The exponent part is added to the \emph{error}, and deleted
-% from the mantissa if necessary.
-%    \begin{macrocode}
-        \ifsi@trapambigerr\else
-          \ifx\@empty\si@num@exp\@empty\else
-            \protected@edef\si@num@err{%
-              \si@num@err\expandafter\@car\si@numexp\@nil
-              \si@num@expsign\si@num@exp}%
-            \ifsi@repeatunits\else
-              \renewcommand*{\si@num@exp}{}%
-              \renewcommand*{\si@num@expsign}{}%
-            \fi
-          \fi
-        \fi
-      \fi
-%    \end{macrocode}
-% If \opt{seperr} is not in force, the error and mantissa have to be
-% recombined.  This is handled so that the same macro deals with
-% tables and normal processing.
-%    \begin{macrocode}
-    \else
-      \expandafter\protected@edef\csname
-        si@\si@tempa @out\endcsname{%
-          \si@num@out\ensuremath{\si@errspace}\ensuremath
-          {\si@openerr}\si@num@err\ensuremath{\si@closeerr}}%
-      \renewcommand*{\si@num@err}{}%
-    \fi
-  \fi
-%    \end{macrocode}
-% The main reconstruction can now occur.  This performs various
-% checks on the validity of the input, and adds the necessary
-% ``filler'' between the supplied data.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{num@out}%
-  \ifsi@num@erropen
-    \renewcommand*{\si@tempa}{num@ambig}%
-  \fi
-  \ifsi@num@intab
-    \renewcommand*{\si@tempa}{tab@expout}%
-  \fi
-  \ifx\@empty\si@num@exp\@empty
-    \ifx\@empty\si@num@mant\@empty
-      \si@log@err{Invalid number format `\si@num@arg'}
-        {Something is wrong with the number format; does it
-         contain \MessageBreak any numbers (from the list
-         `\si@numdigits')?}%
-      \renewcommand*\si@num@out{}%
-    \fi
-  \else
-    \ifx\@empty\si@num@mant\@empty\else
-      \expandafter\protected@edef\csname
-        si@\si@tempa\endcsname{%
-          \csname si@\si@tempa\endcsname\ensuremath{{}%
-          \si@expproduct{}}}%
-    \fi
-    \expandafter\protected@edef\csname
-      si@\si@tempa\endcsname{%
-        \csname si@\si@tempa\endcsname\si@expbase
-        \textsuperscript{\ensuremath{\si@num@expsign}%
-        \si@num@exp}}%
-  \fi
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% With everything done, the result is output.
-%    \begin{macrocode}
-  \ifsi@num@intab\else
-    \expandafter\si@num@out
-  \fi
-%    \end{macrocode}
-%\changes{2009/04/01}{v1.2i}{Minor change for another text mode issue}
-% If there is anything inside the ``x-part'', then there is now
-% more work to do.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@err\@empty\else
-    \expandafter\si@num@procerr
-  \fi
-  \ifsi@num@erropen
-    \expandafter\si@out@num\expandafter{%
-      \ensuremath{\si@closeerr}}%
-      \ifx\@empty\si@num@ambig\@empty\else
-        \si@out@num{\si@num@ambig}%
-        \renewcommand*{\si@num@ambig}{}%
-    \fi
-  \fi
-  \si@num@erropenfalse
-  \ifx\@empty\si@num@xpart\@empty\else
-    \expandafter\si@num@sepxpart
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@findxpart}
-% Before processing the number, any multiplied parts have to be found
-% and removed.  As there can be more than one product sign, the
-% building process here has no error checking.
-%    \begin{macrocode}
-\def\si@num@findxpart#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numprod}
-    {\si@switchtrue\si@seperrfalse}{}%
-  \ifsi@switch
-    \protected@edef\si@num@xpart{\si@num@xpart#1}%
-  \else
-    \protected@edef\si@num@in{\si@num@in#1}%
-  \fi
-  \ifx\@empty#2\@empty\else
-    \si@num@findxpart#2\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@sepmantexp}
-%\begin{macro}{\si@num@mantexp}
-%\darg{number}
-% Splitting the mantissa and exponent first checks for characters to
-% gobble, which are simply thrown away.  For any other input, there
-% are two possibilities.  If the character is an exponent marker,
-% then the package switches from collecting the mantissa to
-% collecting the exponent (after a sanity check).  All other
-% characters are added to either the mantissa or the exponent, as
-% appropriate.
-%    \begin{macrocode}
-\newcommand*{\si@num@sepmantexp}[1]{%
-  \expandafter\si@num@mantexp#1\@empty\@empty}
-\def\si@num@mantexp#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numgobble}
-    {\si@log@debug{Gobbling `#1' in \si@num@arg}}
-    {\si@str@ifchrstr{#1}{\si@numexp}
-       {\ifsi@switch
-          \si@log@err{Duplicate exponent marker found}
-            {Only a single exponent character \MessageBreak
-            (from the list `\si@numexp')\MessageBreak may
-            occur in a numerical argument}%
-        \else
-          \si@log@debug{Exponent marker `#1' found in
-            `\si@num@arg'}%
-        \fi
-        \si@switchtrue}%
-       {\ifsi@switch
-          \expandafter\si@num@addexp
-        \else
-          \expandafter\si@num@addmnt
-        \fi
-        {#1}}}%
-%    \end{macrocode}
-% If the recursion has not bottomed out, another loop occurs.
-%    \begin{macrocode}
-  \ifx\@empty#2\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@sepmantexp
-  \fi
-  {#2}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addmnt}
-%\begin{macro}{\si@num@addexp}
-%\darg{char}
-% To allow \cs{expandafter} use in the above, the actual addition to
-% the appropriate macro is handled here.  Two helper macros are
-% needed.
+%\begin{macro}{\_siunitx_number_process_uncertainty_pad:}
+% Uncertainty is short: add zeros.
 %    \begin{macrocode}
-\newcommand*{\si@num@addmnt}[1]{%
-  \si@num@addmntexp{#1}{mant}{mantissa}}
-\newcommand*{\si@num@addexp}[1]{%
-  \si@num@addmntexp{#1}{exp}{exponent}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addmntexp}
-%\darg{char}
-%\darg{either \texttt{mant} or \texttt{exp}}
-%\darg{info-text}
-% Then the business end.
-%    \begin{macrocode}
-\newcommand*{\si@num@addmntexp}[3]{%
-  \si@log@debug{Adding `#1' to #3 for `\si@num@arg'}%
-  \expandafter\protected@edef\csname si@num@#2\endcsname{%
-    \csname si@num@#2\endcsname#1}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@sepsign}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The input is now tested for a sign.  If one exists, it is
-% transferred into the \cs{si@num@}|#1sign| storage macro, with the
-% remained of the number in \cs{si@num@}|#1|.  The only check made
-% directly here is that there is something to process.
-%    \begin{macrocode}
-\newcommand*{\si@num@sepsign}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@gensign
-  \fi
-  {#1}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@gensign}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The sign generator starts by calling the procedure to check if the
-% input contains a valid one- or two-digit sign.  The results are
-% returned as \cs{si@num@sign} and \cs{si@num@value}.
-%    \begin{macrocode}
-\newcommand*{\si@num@gensign}[1]{%
-  \expandafter\expandafter\expandafter\si@num@findsign
-    \csname si@num@#1\endcsname\@empty\@empty
-%    \end{macrocode}
-% If no sign has been found, then there may be a need to add one
-% anyway.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@sign\@empty
-    \ifx\@empty\si@num@value\@empty
-      \expandafter\expandafter\expandafter\@gobble
-    \else
-      \expandafter\expandafter\expandafter\si@num@addsign
-    \fi
-  \else
-    \expandafter\@gobble
-  \fi
-  {#1}%
-%    \end{macrocode}
-% The appropriate storage areas are now assigned.
-%    \begin{macrocode}
-  \expandafter\let\csname si@num@#1sign\endcsname\si@num@sign
-  \expandafter\let\csname si@num@#1\endcsname\si@num@value}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@findsign}
-%\begin{macro}{\si@num@sign}
-%\begin{macro}{\si@num@value}
-% The first one or two characters of the mantissa or exponent may
-% contain a sign.  To test for this, the first two characters of the
-% number are split off, and examined.  Two characters are used so
-% that \cs{pm} and \cs{mp} can be represented by |+-| and |-+|,
-% respectively. To allow the user to alter the valid signs, but
-% retain this conversion, the generic character test is used before
-% checking specific matches.
-%    \begin{macrocode}
-\newcommand*{\si@num@sign}{}
-\def\si@num@findsign#1#2#3\@empty{%
-  \si@num@delplusfalse
-  \si@str@ifchrstr{#1}{\si@numsign}{%
-    \si@str@ifchrstr{#2}{\si@numsign}{%
-      \if +#1%
-        \if -#2%
-          \si@log@debug{Found sign combination +- for
-            `\si@num@arg'}%
-          \renewcommand*{\si@num@sign}{{\si@pm}}%
-        \else
-          \si@log@inf{Unknown sign combination `#1#2'}%
-          \renewcommand*{\si@num@sign}{{#1#2}}%
-        \fi
-      \else
-        \if -#1%
-          \if +#2%
-            \si@log@debug{Found sign combination -+ for
-              `\si@num@arg'}%
-            \renewcommand*{\si@num@sign}{{\mp}}%
-          \else
-            \si@log@inf{Unknown sign combination `#1#2'}%
-            \renewcommand*{\si@num@sign}{{#1#2}}%
-          \fi
-        \else
-          \si@log@inf{Unknown sign combination `#1#2'}%
-          \renewcommand*{\si@num@sign}{{#1#2}}%
-        \fi
-      \fi
-      \protected@edef\si@num@value{#3}}%
-%    \end{macrocode}
-% Only one valid sign character.
-%    \begin{macrocode}
-      {\si@log@debug{Found single sign character `#1' for
-         `\si@num@arg'}%
-       \renewcommand*{\si@num@sign}{{#1}}%
-       \if +#1%
-         \ifsi@retainplus\else
-           \expandafter\expandafter\expandafter\si@num@killsign
-         \fi
-       \fi
-       \protected@edef\si@num@value{#2#3}}}%
-%    \end{macrocode}
-% No valid sign, so \cs{@empty} is returned for the sign .
-%    \begin{macrocode}
-    {\si@log@debug{No sign found for `\si@num@arg'}%
-     \renewcommand*{\si@num@sign}{}%
-     \protected@edef\si@num@value{#1#2#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@num@delplus}
-%\begin{macro}{\si@num@killsign}
-% A simple spin-out to remove a plus sign.  A flag is set as it might
-% be useful to know this.
-%    \begin{macrocode}
-\newif\ifsi@num@delplus
-\newcommand*{\si@num@killsign}{%
-  \si@num@delplustrue
-  \renewcommand*{\si@num@sign}{}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addsign}
-%\begin{macro}{\si@num@asign}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The macro to add a sign to an unsigned number has to check whether
-% this is a mantissa or an exponent.  The result is still placed in
-% \cs{si@num@sign} for ease of processing later.
-%    \begin{macrocode}
-\newcommand*{\si@num@addsign}[1]{%
-  \begingroup
-    \renewcommand*{\si@tempa}{#1}%
-    \renewcommand*{\si@tempb}{mant}%
-    \ifx\si@tempa\si@tempb
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup
-  {\ifsi@num@signmant
-     \expandafter\si@num@asign
-   \else
-     \expandafter\@gobble
-   \fi
-   {mantissa}}
-  {\ifsi@num@signexp
-     \expandafter\si@num@asign
-   \else
-     \expandafter\@gobble
-   \fi
-   {exponent}}}
-\newcommand*{\si@num@asign}[1]{%
-  \let\si@num@sign\si@sign
-  \si@log@debug{Adding sign \si@sign\space to #1 for
-    `\si@num@arg'}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@procnum}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The control macro for processing the number (plus any extra
-% characters).
-%    \begin{macrocode}
-\newcommand*{\si@num@procnum}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@finddigits
-  \fi
-  {#1}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@predec}
-%\begin{macro}{\si@num@postdec}
-% Two new storage areas are defined.
-%    \begin{macrocode}
-\newcommand*{\si@num@predec}{}
-\newcommand*{\si@num@postdec}{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@finddigits}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The core digit processor divides the number into the parts before
-% and after the decimal point marker.  The temporary switch is used
-% to indicate finding a decimal marker.
-%    \begin{macrocode}
-\newcommand*{\si@num@finddigits}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \expandafter\expandafter\expandafter\si@num@digits
-    \csname si@num@#1\endcsname\@empty\@empty
-%    \end{macrocode}
-% Tests are now made to see if padding zeros are needed.  The
-% trailing test needs to verify if a decimal marker was found, as
-% well as if a zero is needed.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@predec\@empty
-    \ifsi@num@padlead
-      \expandafter\expandafter\expandafter\si@num@addprezero
-    \fi
-  \fi
-  \ifx\@empty\si@num@postdec\@empty
-    \ifsi@num@padtrail
-      \ifsi@switch
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter
-          \si@num@addpostzero
-      \fi
-    \fi
-  \fi
-%    \end{macrocode}
-% The next checks to make concern input validity in a more
-% mathematical sense.  First, if the number is zero, then no sign
-% should be given under any circumstances.  Then leading zeros need
-% to be removed from the input.  This is slightly complicated by the
-% potential presence of ``extra'' characters.
-%    \begin{macrocode}
-  \si@num@unsign{#1}%
-  \ifx\@empty\si@num@predec\@empty
-  \else
-    \expandafter\si@num@nozero
-  \fi
-%    \end{macrocode}
-% A sanity check is made to ensure that the supplied number consisted
-% of more than a decimal marker.
-%    \begin{macrocode}
-  \ifx\@empty\si@num@predec\@empty
-    \ifx\@empty\si@num@postdec\@empty
-      \expandafter\expandafter\expandafter\@gobble
-    \else
-      \expandafter\expandafter\expandafter\si@num@sepdigits
-    \fi
-  \else
-    \expandafter\si@num@sepdigits
-  \fi
-  {#1}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@digits}
-% The \cs{si@num@digits} macro compares each character in the input
-% against the list of characters valid at this stage: numbers,
-% decimal markers and ``extra'' characters.
-%    \begin{macrocode}
-\def\si@num@digits#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numdecimal}
-    {\ifsi@switch
-       \si@log@err{Duplicate decimal marker in `\si@num@arg'}
-         {Only a single decimal marker (from the list
-            `\si@numdecimal')\MessageBreak may occur in a
-            numerical argument}%
-     \else
-       \si@log@debug{Found decimal marker `#1' in
-         `\si@num@arg'}%
-       \expandafter\si@switchtrue
-     \fi}
-%    \end{macrocode}
-% The earlier code only checks for a sign at the start of the text. A
-% check is therefore needed for a sign after the first two
-% characters; if one is found, it is ignored.
-%    \begin{macrocode}
-    {\si@str@ifchrstr{#1}{\si@numsign}
-       {\si@log@err{Misplaced sign character
-          `#1' in `\si@num@arg'}
-          {Sign characters `\si@numsign' can only
-            occur\MessageBreak at the start of a number}}
-%    \end{macrocode}
-% The current character is added to the appropriate stack; this is
-% ``spun out'' to avoid problems with expansion of the switch code.
-%    \begin{macrocode}
-       {\ifsi@switch
-          \expandafter\si@num@post
-        \else
-          \expandafter\si@num@pre
-        \fi
-        {#1}}}%
-  \ifx\@empty#2\@empty\else
-    \si@num@digits#2\@empty\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@pre}
-%\begin{macro}{\si@num@post}
-%\darg{char}
-% Storage of the result is spun out.
-%    \begin{macrocode}
-\newcommand*{\si@num@pre}[1]{%
-  \si@num@prepost{#1}{pre}{integer}}
-\newcommand*{\si@num@post}[1]{%
-  \si@num@prepost{#1}{post}{decimal}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@prepost}
-%\darg{char}
-%\darg{either \texttt{pre} or \texttt{post}}
-%\darg{info-text}
-% Then actually stored here.
-%    \begin{macrocode}
-\newcommand*{\si@num@prepost}[3]{%
-  \expandafter\protected@edef\csname si@num@#2dec\endcsname{%
-    \csname si@num@#2dec\endcsname#1}%
-  \si@log@debug{Adding `#1' to #3 part for `\si@num@arg'}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@addprezero}
-%\begin{macro}{\si@num@addpostzero}
-% A similar set of macros are used for the padding zeros.
-%    \begin{macrocode}
-\newcommand*{\si@num@addprezero}{%
-  \si@num@addpzero{pre}{leading}}
-\newcommand*{\si@num@addpostzero}{%
-  \si@num@addpzero{post}{trailing}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addpzero}
-%\darg{either \texttt{pre} or \texttt{post}}
-% In this case, there is no argument to be passed along.
-%    \begin{macrocode}
-\newcommand*{\si@num@addpzero}[2]{%
-  \si@log@debug{Adding #2 zero for `\si@num@arg'}%
-  \@namedef{si@num@#1dec}{0}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@unsign}
-%\begin{macro}{\si@num@nosign}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The trap for a sign with zero numerical input is made.  First, a
-% check is made to see if there is a sign to worry about.  The pre-
-% and post-decimal parts are then examined, to see if they contain
-% something other than ``0'' or an extra character.
-%    \begin{macrocode}
-\newcommand*{\si@num@unsign}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1sign\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@nosign
-  \fi
-  {#1}}
-\newcommand*{\si@num@nosign}[1]{%
-  \begingroup
-    \si@switchtrue
-    \si@str@ifonlychrs{\si@num@predec\si@num@postdec}{0}
-      {\si@switchfalse}{}%
-    \ifsi@switch
-      \aftergroup\@gobble
-    \else
-      \aftergroup\@firstofone
-    \fi
-  \endgroup
-  {\si@log@debug{Zero value: removing any sign}%
-   \ifsi@ang@sign\else
-     \@namedef{si@num@#1sign}{}%
-   \fi}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@nozero}
-%  A very short test for a totally zero pre-decimal component.
-%    \begin{macrocode}
-\newcommand*{\si@num@nozero}{%
-  \si@str@ifonlychrs{\si@num@predec}{0}
-    {\renewcommand*{\si@num@predec}{0}}{}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@decimalhook}
-% A hook is needed to attach things inside the group to happen
-% afterwards, if the number is a decimal.
-%    \begin{macrocode}
-\newcommand*{\si@num@decimalhook}{}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@sepdigits}
-%\darg{either \texttt{mant} or \texttt{exp}}
-% The \cs{si@num@sepdigits} macro is only called if at least one of
-% the mantissa and exponent contain something to output.
-%    \begin{macrocode}
-\newcommand*{\si@num@sepdigits}[1]{%
-%    \end{macrocode}
-% First an overall check is needed for additional characters.  By
-% altering the contents of \cs{si@numextra}, the same code can be
-% shared by two different checks.
-%    \begin{macrocode}
-  \begingroup
-    \let\si@numextra\si@numaddn
-    \protected@edef\si@tempa{\si@num@predec\si@num@postdec}%
-    \si@num@ifextra{\si@tempa}
-      {\aftergroup\@gobble}
-      {\aftergroup\@firstofone}%
-  \endgroup
-%    \end{macrocode}
-% Separation of the error in a number from the number itself is only
-% attempted for the mantissa.
-%    \begin{macrocode}
-  {\renewcommand*{\si@tempb}{mant}%
-   \renewcommand*{\si@tempc}{#1}%
-   \ifx\si@tempb\si@tempc
-     \expandafter\si@num@checkerr
-   \fi}%
-%    \end{macrocode}
-%\changes{v1.1}{2008/08/22}{Fixed-length code generalised}
-%\changes{v1.1}{2008/08/26}{Length-fixing only applies to
-%  manitssa}
-% If both parts of the number contain only digits, then any rounding
-% can be attempted if there is no error part.  Otherwise, the input
-% must be left alone.
-%    \begin{macrocode}
-  \protected@edef\si@tempa{\si@num@predec\si@num@postdec}%
-  \expandafter\si@str@ifonlychrs\expandafter{\si@tempa}
-    {0123456789}
-    {\ifx\@empty\si@num@err\@empty
-       \renewcommand*{\si@tempb}{mant}%
-       \renewcommand*{\si@tempc}{#1}%
-       \ifx\si@tempb\si@tempc
-         \expandafter\expandafter\expandafter\si@num@fixlength
-       \fi
-     \fi}{}%
-%    \end{macrocode}
-% If the pre-decimal part contains nothing except numbers, then
-% digit separation is carried out.
-%    \begin{macrocode}
-  \si@num@ifextra{\si@num@predec}{}
-    {\expandafter\si@num@int\expandafter{\si@num@predec}}%
-%    \end{macrocode}
-% A decision is made about the decimal sign, then digit separation
-% occurs on the post-decimal part of the number.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempc}{}%
-  \ifx\@empty\si@num@postdec\@empty\else
-    \si@num@decimalhook
-    \renewcommand*{\si@tempc}{%
-      \ensuremath{{\si@decimalsymbol}}}%
-    \si@num@ifextra{\si@num@postdec}{}
-      {\expandafter\si@num@dec\expandafter{\si@num@postdec}}%
-  \fi
-%    \end{macrocode}
-% The construction is finalised by re-combining the number.
-%    \begin{macrocode}
-  \expandafter\protected@edef\csname si@num@#1\endcsname
-    {\si@num@predec\si@tempc\si@num@postdec}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@ifextra}
-%\begin{macro}{\si@num@extra}
-%\darg{number}
-% A relatively simple test for ``extra'' characters.  Once again, a
-% bit of group trickery is used.
-%    \begin{macrocode}
-\newcommand*{\si@num@ifextra}[1]{%
-  \begingroup
-    \si@switchfalse
-    \expandafter\si@num@extra#1\@empty\@empty
-    \ifsi@switch
-      \si@log@debug{Found `extra' characters in `#1'}%
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@num@extra#1#2\@empty{%
-  \ifx\@empty#1\@empty\else
-    \si@str@ifchrstr{#1}{\si@numextra}{\si@switchtrue}{}%
-    \ifx\@empty#2\@empty\else
-      \si@num@extra#2\@empty\@empty
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@num@ambigerr}
-%\begin{macro}{\si@num@checkerr}
-% When separating out an error from a number, the first step is to
-% see if there is a decimal part to the number.  If so, any error
-% must be in that part of the decimal part; it is not possible to
-% have an error starting in the integer part and continuing into the
-% decimal part.
-%    \begin{macrocode}
-\newif\ifsi@num@ambigerr
-\newcommand*{\si@num@checkerr}{%
-  \ifx\@empty\si@num@postdec\@empty
-    \expandafter\si@num@preerr
-  \else
-    \expandafter\si@num@posterr
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@preerr}
-% Errors in integers are easy to handle.  After finding the error,
-% the result is simply stored in the error macro \cs{si@num@err}.
-%    \begin{macrocode}
-\newcommand*{\si@num@preerr}{%
-  \si@num@seperr{pre}%
-  \ifx\@empty\si@tempb\@empty\else
-    \expandafter\renewcommand\expandafter*\expandafter
-      \si@num@err\expandafter{\si@tempb}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@posterr}
-%\begin{macro}{\si@num@psterr}
-% Life is more complex for an error in the decimal part.  This is
-% found, then it may need zero-filling or the insertion of a decimal
-% point.  This depends on whether the number of error digits is
-% larger than the number of post-decimal digits.
-%    \begin{macrocode}
-\newcommand*{\si@num@posterr}{%
-  \si@num@seperr{post}%
-  \ifx\@empty\si@tempb\@empty\else
-    \ifsi@seperr
-      \expandafter\expandafter\expandafter\si@num@psterr
-    \else
-      \let\si@num@err\si@tempb
-    \fi
-  \fi}
-\newcommand*{\si@num@psterr}{%
-    \si@num@cntdigits{\si@tempb}%
-    \si@tempcntb\si@tempcnta\relax
-    \si@num@cntdigits{\si@num@postdec}%
-    \ifnum\si@tempcnta<\si@tempcntb\relax
-      \expandafter\si@num@largeerr
-    \else
-      \expandafter\si@num@smallerr
-    \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@seperr}
-%\begin{macro}{\si@num@finderr}
-%\darg{either \texttt{pre} or \texttt{post}}
-% The usual hand-off is made for searching for an error.
-%    \begin{macrocode}
-\newcommand*{\si@num@seperr}[1]{%
-  \si@switchfalse
-  \renewcommand*{\si@tempa}{}%
-  \renewcommand*{\si@tempb}{}%
-  \expandafter\expandafter\expandafter\si@num@finderr
-    \csname si@num@#1dec\endcsname\@empty\@empty
-  \ifx\@empty\si@tempb\@empty\else
-    \expandafter\let\csname si@num@#1dec\endcsname\si@tempa
-  \fi}
-\def\si@num@finderr#1#2\@empty{%
-%    \end{macrocode}
-% First a check for the opening character of an error.
-%    \begin{macrocode}
-  \si@str@ifchrstr{#1}{\si@numopenerr}
-%    \end{macrocode}
-% If the switch is set when an error is found, then something is
-% wrong.
-%    \begin{macrocode}
-    {\ifsi@switch
-       \si@log@err{Invalid error in number}
-         {The numerical argument \si@num@arg\space has two (or
-           more)\MessageBreak error-opening characters}%
-     \else
-       \expandafter\si@switchtrue
-     \fi}
-%    \end{macrocode}
-% The end-of-error character has to be the last item of the input,
-% and an error needs to start before it ends.
-%    \begin{macrocode}
-    {\si@str@ifchrstr{#1}{\si@numcloseerr}
-       {\ifsi@switch
-          \ifx\@empty#2\@empty\else
-            \si@log@err{Invalid error in number}
-              {The numerical argument \si@num@arg\space has an
-              error-closing before the last character}%
-          \fi
-        \else
-          \si@log@err{Invalid error in number}
-           {The numerical argument \si@num@arg\space has an
-              error-closing character\MessageBreak but no
-              error-opening one}%
-        \fi}
-%    \end{macrocode}
-% The input must be a digit.  It is stored in the appropriate area.
-%    \begin{macrocode}
-       {\ifsi@switch
-          \expandafter\si@num@addtmpb
-        \else
-          \expandafter\si@num@addtmpa
-        \fi
-        {#1}}}%
-  \ifx\@empty#2\@empty\else
-    \si@num@finderr#2\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addtmpa}
-%\begin{macro}{\si@num@addtmpb}
-%\darg{number}
-% Some quick methods for adding to the temporary macros with \cs{if}
-% expansion.
-%    \begin{macrocode}
-\newcommand*{\si@num@addtmpa}[1]{\si@num@addtmp{a}{#1}}
-\newcommand*{\si@num@addtmpb}[1]{\si@num@addtmp{b}{#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@addtmp}
-%\darg{either \texttt{a} or \texttt{b}}
-%\darg{number}
-% The addition is committed.
-%    \begin{macrocode}
-\newcommand*{\si@num@addtmp}[2]{%
-  \expandafter\protected@edef\csname si@temp#1\endcsname{%
-    \csname si@temp#1\endcsname#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@cntdigits}
-%\begin{macro}{\si@num@cntdgt}
-%\darg{number}
-% A recursive system for counting the number of characters in a given
-% input; only used here to count digits in a number.
-%    \begin{macrocode}
-\newcommand*{\si@num@cntdigits}[1]{%
-  \si@tempcnta\z@\relax
-  \expandafter\si@num@cntdgt#1\@empty\@empty}
-\def\si@num@cntdgt#1#2\@empty{%
-  \ifx\@empty#1\@empty\else
-    \advance\si@tempcnta\@ne\relax
-  \fi
-  \ifx\@empty#2\@empty\else
-    \expandafter\si@num@cntdgt#2\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@smallerr}
-%\begin{macro}{\si@num@serr}
-% For handling an error with no more digits than the post-decimal
-% part of a number, zero-padding is undertaken before adding a
-% decimal sign and (possibly) leading zero.
-%    \begin{macrocode}
-\newcommand*{\si@num@smallerr}{%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@serr
-  \protected@edef\si@num@err{%
-    \ifsi@num@padlead0\fi\expandafter\@car\si@numdecimal\@nil
-    \si@tempb}}
-\newcommand*{\si@num@serr}{%
-  \si@num@cntdigits{\si@tempb}%
-  \ifnum\si@tempcnta=\si@tempcntb\relax\else
-    \protected@edef\si@tempb{0\si@tempb}%
-    \expandafter\si@num@serr
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@largeerr}
-%\changes{v1.0m}{2008/09/16}{Fixed problem with error separation
-%  crossing decimal boundary}
-%\begin{macro}{\si@num@lerr}
-%\begin{macro}{\si@num@movedigit}
-% When the error has more digits than the decimal part, some
-% shuffling is needed.
-%    \begin{macrocode}
-\newcommand*{\si@num@largeerr}{%
-  \renewcommand*{\si@tempa}{}%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@lerr
-  \protected@edef\si@num@err{%
-    \si@tempa\expandafter\@car\si@numdecimal\@nil\si@tempb}}
-\newcommand*{\si@num@lerr}{%
-  \si@num@cntdigits{\si@tempb}%
-  \ifnum\si@tempcnta=\si@tempcntb\relax\else
-    \expandafter\si@num@movedigit\si@tempb\@empty\@empty
-    \si@num@lerr
-  \fi}
-\def\si@num@movedigit#1#2\@empty{%
-  \protected@edef\si@tempa{\si@tempa#1}%
-  \protected@edef\si@tempb{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@fixlength}
-% The checks for fixing number length are spun out here.
-%    \begin{macrocode}
-\newcommand*{\si@num@fixlength}{%
-  \ifsi@fixdp
-    \expandafter\si@num@fixdp
-  \else
-    \ifsi@fixsf
-      \expandafter\expandafter\expandafter\si@num@fixsf
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@fixdp}
-% The test for fixing decimal places starts by counting up the number
-% of decimal digits.  The number is then padded, rounded or left
-% alone.
-%    \begin{macrocode}
-\newcommand*{\si@num@fixdp}{%
-  \si@num@cntdigits{\si@num@postdec}%
-  \ifx\@empty\si@num@postdec\@empty
-    \si@tempcnta\z@\relax
-  \fi
-  \ifnum\si@tempcnta>\si@num@dp\relax
-    \expandafter\si@num@round
-  \else
-    \ifnum\si@tempcnta<\si@num@dp\relax
-      \expandafter\expandafter\expandafter\si@num@pad
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@pad}
-%\begin{macro}{\si@num@pd}
-% Padding a number is a relatively easy matter.  The number of digits
-% is increased by adding ``$0$'' recursively.
-%    \begin{macrocode}
-\newcommand*{\si@num@pad}{%
-  \si@log@debug{Padding to \the\si@num@dp\space digits}%
-  \loop\ifnum\si@tempcnta<\si@num@dp\si@num@pd\repeat}
-\newcommand*{\si@num@pd}{%
-  \advance\si@tempcnta\@ne\relax
-  \protected@edef\si@num@postdec{\si@num@postdec0}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@rndtarget}
-%\changes{v1.1}{2008/08/25}{New counter}
-% A scratch counter is created to allow some code sharing between
-% fixing decimal places and significant figures.
-%    \begin{macrocode}
-\newcount\si@num@rndtarget
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@round}
-%\begin{macro}{\si@num@prernd}
-%\begin{macro}{\si@num@postrnd}
-%\begin{macro}{\si@num@rndstart}
-%\changes{v1.1}{2008/08/25}{Separated out from \cs{si@num@round}}
-% Rounding a number is more complicated.  The main macro here relies
-% on several others, and is simply a set-up and hand-off system.
-%    \begin{macrocode}
-\newcommand*{\si@num@prernd}{}
-\newcommand*{\si@num@postrnd}{}
-\newcommand*{\si@num@round}{%
-  \si@log@debug{Rounding to \the\si@num@dp\space digits}%
-  \si@num@rndtarget\si@num@dp\relax
-  \si@num@rndstart}
-\newcommand*{\si@num@rndstart}{%
-  \si@num@reverse{\si@num@postdec}%
-  \si@num@reverse{\si@num@predec}%
-  \let\si@num@prernd\si@num@predec
-  \let\si@num@postrnd\si@num@postdec
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \si@num@rnd}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@reverse}
-%\begin{macro}{\si@num@rev}
-%\darg{storage-macro}
-% The initial stage is to reverse the entire number, to make life
-% easier.  This is then undone by the other macros as the output is
-% constructed.
-%    \begin{macrocode}
-\newcommand*{\si@num@reverse}[1]{%
-  \renewcommand*{\si@tempa}{}%
-  \expandafter\si@num@rev#1\@empty\@empty
-  \let#1\si@tempa}
-\def\si@num@rev#1#2\@empty{%
-  \edef\si@tempa{#1\si@tempa}%
-  \ifx\@empty#2\@empty\else
-    \si@num@rev#2\@empty\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@rnd}
-%\changes{v1.1}{2008/08/25}{Altered check for ending to generalise
-%  code}
-%\begin{macro}{\si@num@rndpre}
-%\begin{macro}{\si@num@rndpost}
-%\changes{v1.0b}{2008/06/23}{Corrected bug in rounding code}
-% The core looping macro of the system simply divides the flow
-% between rounding before and after the decimal.  The two routines
-% are quite similar, but have subtly different requirements.  Both
-% take one character at a time from the input, increment if there is
-% a carry digit, check its value, and add to the output string. This
-% is very similar to the same routines used in other macro packages
-% to achieve the same thing.
-%    \begin{macrocode}
-\newcommand*{\si@num@rnd}{%
-  \ifx\@empty\si@num@postrnd\@empty
-    \expandafter\si@num@rndpre
-  \else
-    \expandafter\si@num@rndpost
-  \fi}
-\newcommand*{\si@num@rndpre}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@prernd\@nil}%
-  \expandafter\edef\expandafter\si@num@prernd\expandafter{%
-    \expandafter\@cdr\si@num@prernd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \ifnum\si@tempcntb=10\relax
-    \si@tempcntb\z@\relax
-    \expandafter\expandafter\expandafter\si@switchtrue
-  \fi
-  \edef\si@num@predec{\the\si@tempcntb\si@num@predec}%
-  \ifx\@empty\si@num@prernd\@empty
-    \ifsi@switch
-      \edef\si@num@predec{1\si@num@predec}%
-    \fi
-  \else
-    \expandafter\si@num@rnd
-  \fi}
-\newcommand*{\si@num@rndpost}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@postrnd\@nil}%
-  \expandafter\edef\expandafter\si@num@postrnd\expandafter{%
-    \expandafter\@cdr\si@num@postrnd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \advance\si@num@rndtarget\@ne\relax
-  \ifnum\si@tempcnta>\si@num@rndtarget\relax
-    \advance\si@num@rndtarget\m@ne\relax
-  \else
-    \advance\si@num@rndtarget\m@ne\relax
-    \ifnum\si@tempcnta>\si@num@rndtarget\relax
-      \ifnum\si@tempcntb>4\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-    \else
-      \ifnum\si@tempcntb=10\relax
-        \si@tempcntb\z@\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@postdec{\the\si@tempcntb\si@num@postdec}%
-    \fi
-  \fi
-  \advance\si@tempcnta\m@ne\relax
-%    \end{macrocode}
-% If \cs{si@tempcnta} is negative, this must be the significant
-% figures routine and one digit needs to be thrown away.
-%    \begin{macrocode}
-  \ifnum\si@tempcnta=\m@ne\relax
-    \si@num@throw
-  \fi
-  \si@num@rnd}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@throw}
-% Throw one digit away from the end of the post-decimal part.
-%    \begin{macrocode}
-\newcommand*{\si@num@throw}{%
-  \si@num@reverse{\si@num@postdec}%
-  \edef\si@num@postdec{\expandafter\@cdr\si@num@postdec\@nil}%
-  \si@num@reverse{\si@num@postdec}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@fixsf}
-% Setting up a fixed number of significant figures is rather more
-% complicated than fixing the decimal places.  There are a number of
-% tests needed to see what needs to be done.
-%    \begin{macrocode}
-\newcommand*{\si@num@fixsf}{%
-  \si@num@cntdigits{\si@num@predec}%
-  \ifx\@empty\si@num@predec\@empty
-    \si@tempcnta\z@\relax
-  \fi
-%    \end{macrocode}
-% If the pre-decimal component has only a single digit, it could be
-% ``0'': if so, only the significant figures in the decimal part are
-% counted.
-%    \begin{macrocode}
-  \ifnum\si@tempcnta=\@ne\relax
-    \renewcommand*{\si@tempa}{0}%
-    \ifx\si@num@predec\si@tempa
-%    \end{macrocode}
-% The number of significant digits after the decimal point have to be
-% counted up. If there are enough digits there, then some rounding
-% will again be needed.
-%    \begin{macrocode}
-      \ifx\@empty\si@num@postdec\@empty\else
-        \si@tempcnta\z@\relax
-        \si@switchfalse
-        \expandafter\si@num@cntpostsf\si@num@postdec
-          \@empty\@empty
-        \ifnum\si@tempcnta>\si@num@sf\relax
-          \si@log@debug{Rounding to \the\si@num@sf\space
-            figures}%
-          \si@num@rndtarget\si@num@sf\relax
-          \si@num@rndstart
-        \fi
-      \fi
-    \else
-      \si@num@cntprepost
-    \fi
-  \else
-%    \end{macrocode}
-% If there are too many digits in the pre-decimal part, a check is
-% first made to see if there may be a need to round from the first
-% post-decimal digit. If not, the post decimal part is thrown away.
-%    \begin{macrocode}
-    \ifnum\si@tempcnta<\si@num@sf\relax
-      \si@num@cntprepost
-    \else
-      \advance\si@tempcnta\m@ne\relax
-      \si@switchfalse
-      \ifnum\si@tempcnta>\si@num@sf\relax\else
-        \ifx\@empty\si@num@postdec\@empty\else
-          \edef\si@num@postdec{\expandafter\@car
-            \si@num@postdec\@nil}%
-          \ifnum\si@num@postdec>4\relax
-            \expandafter\si@switchtrue
-          \fi
-        \fi
-      \fi
-      \advance\si@tempcnta\@ne\relax
-      \renewcommand*{\si@num@postdec}{}%
-      \si@num@reverse{\si@num@predec}%
-      \let\si@num@prernd\si@num@predec
-      \renewcommand*{\si@num@predec}{}%
-      \si@num@sfpre
-      \ifsi@switch
-        \edef\si@num@predec{1\si@num@predec}%
-      \fi
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@cntpostsf}
-% Counting up significant figures in the post-decimal part needs an
-% auxiliary macro.
-%    \begin{macrocode}
-\def\si@num@cntpostsf#1#2\@empty{%
-  \ifsi@switch
-    \advance\si@tempcnta\@ne\relax
-  \else
-    \if 0#1\relax\else
-      \si@tempcnta\@ne\relax
-      \expandafter\expandafter\expandafter\si@switchtrue
-    \fi
-  \fi
-  \ifx\@empty#2\@empty\else
-    \si@num@cntpostsf#2\@empty\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@cntprepost}
-% There are two routes to find that the number of digits in both
-% parts of the number are important.  In either case, rounding is
-% only needed if the two parts have too many digits.
-%    \begin{macrocode}
-\newcommand*{\si@num@cntprepost}{%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@cntdigits{\si@num@postdec}%
-  \advance\si@tempcnta\si@tempcntb\relax
-  \ifnum\si@tempcnta>\si@num@sf
-    \si@log@debug{Rounding to \the\si@num@sf\space figures}%
-    \si@num@rndtarget\si@num@sf\relax
-    \si@num@rndstart
-    \ifsi@switch
-      \si@num@throw
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@sfpre}
-% The code here is very similar to that used to round to a fixed
-% number of decimal places.
-%    \begin{macrocode}
-\newcommand*{\si@num@sfpre}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@prernd\@nil}%
-  \expandafter\edef\expandafter\si@num@prernd\expandafter{%
-    \expandafter\@cdr\si@num@prernd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \advance\si@num@sf\@ne\relax
-  \ifnum\si@tempcnta>\si@num@sf\relax
-    \advance\si@num@sf\m@ne\relax
-    \edef\si@num@predec{0\si@num@predec}%
-  \else
-    \advance\si@num@sf\m@ne\relax
-    \ifnum\si@tempcnta>\si@num@sf\relax
-      \ifnum\si@tempcntb>4\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@predec{0\si@num@predec}%
-    \else
-      \ifnum\si@tempcntb=10\relax
-        \si@tempcntb\z@\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@predec{\the\si@tempcntb\si@num@predec}%
-    \fi
-  \fi
-  \advance\si@tempcnta\m@ne\relax
-  \ifx\@empty\si@num@prernd\@empty\else
-    \expandafter\si@num@sfpre
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%
-%\begin{macro}{\si@num@int}
-%\darg{integer-part}
-% The formatting code for separating thousands is taken more-or-less
-% directly from \SIstyle.  A few changes are made to fit the various
-% conventions here.  Following on from the code above, \cs{si@tempa}
-% is used to store the integer part of the number, and \cs{si@tempb}
-% is used for the decimal part.
-%    \begin{macrocode}
-\newcommand*{\si@num@int}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \ifsi@sepfour
-    \si@num@intfmt{}#1\@empty\@empty\@empty
-  \else
-    \si@num@iffive{#1}
-      {\si@num@intfmt{}#1\@empty\@empty\@empty}
-      {\renewcommand*{\si@num@predec}{#1}}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@iffive}
-%\begin{macro}{\si@num@five}
-%\darg{number}
-% A test is needed for the presence of more than four characters.
-%    \begin{macrocode}
-\newcommand*{\si@num@iffive}[1]{%
-  \si@num@five#1\@empty\@empty\@empty\@empty\@empty\end}
-\def\si@num@five#1#2#3#4#5\end{%
-   \ifx\@empty#5\@empty
-      \expandafter\@secondoftwo
-   \else
-      \expandafter\@firstoftwo
-   \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@intfmt}
-%\begin{macro}{\si@num@fiint}
-% The business end of the integer formatter.
-%    \begin{macrocode}
-\newcommand*{\si@num@intfmt}[4]{%
-  \ifx\@empty#2\@empty
-    \si@num@intsep#1\relax
-  \else
-    \ifx\@empty#3\@empty
-      \si@num@intsep\@empty\@empty#1#2\relax
-    \else
-      \ifx\@empty#4\@empty
-        \si@num@intsep\@empty#1#2#3\relax
-      \else
-        \si@num@fiint{#1#2#3#4}%
-      \fi
-    \fi
-  \fi}
-\def\si@num@fiint#1\fi\fi\fi{\fi\fi\fi\si@num@intfmt{#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@intsep}
-% For adding separation to integers, an extra function is needed.
-%    \begin{macrocode}
-\newcommand*{\si@num@intsep}[4]{%
-  \protected@edef\si@num@predec{\si@num@predec#1#2#3}%
-  \if\relax#4\relax\else
-    \protected@edef\si@num@predec{%
-      \si@num@predec\ensuremath{\noexpand\si@digitsep}}%
-    \expandafter\si@num@intsep\expandafter#4%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@dec}
-%\begin{macro}{\si@num@decfmt}
-%\darg{decimal-part}
-% Formatting a decimal uses a similar mechanism, but with a few
-% alterations needed.
-%    \begin{macrocode}
-\newcommand*{\si@num@dec}[1]{%
-  \renewcommand*{\si@num@postdec}{}%
-  \ifsi@sepfour
-    \si@num@decfmt#1\@empty\@empty\@empty\@empty
-  \else
-    \si@num@iffive{#1}
-      {\si@num@decfmt#1\@empty\@empty\@empty\@empty}
-      {\protected@edef\si@num@postdec{\si@num@postdec#1}}%
-  \fi}
-\newcommand*{\si@num@decfmt}[4]{%
-  \protected@edef\si@num@postdec{\si@num@postdec#1#2#3}%
-  \ifx\@empty#4\@empty%
-  \else
-    \protected@edef\si@num@postdec{%
-      \si@num@postdec\ensuremath{\noexpand\si@digitsep}}%
-    \expandafter\si@num@decfmt\expandafter#4%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@num@procerr}
-% Any error is recycled to to formatted correctly.  The $\pm$ sign,
-% and any unit, are also added.
-%    \begin{macrocode}
-\newcommand*{\si@num@procerr}{%
-  \si@num@addunit
-  \ensuremath{\si@pm}%
-  \expandafter\si@num\expandafter{\si@num@err}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@sepxpart}
-%\changes{v1.3}{2009/09/20}{Problem using \opt{textmode} corrected}
-% A similar approach for numbers containing products, except the
-% first token of the input has to be deleted.
-%    \begin{macrocode}
-\newcommand*{\si@num@sepxpart}{%
-  \si@num@addunit
-  \ensuremath{{}\times{}}%
-  \expandafter\expandafter\expandafter\si@num\expandafter
-    \expandafter\expandafter{%
-      \expandafter\@cdr\si@num@xpart\@nil}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@num@addunit}
-%\changes{v1.2h}{2008/03/26}{Minor bug fix for repeated units and text
-%  mode values}
-% A short macro to add units if needed.
-%    \begin{macrocode}
-\newcommand*{\si@num@addunit}{%
-  \si@unt@numtrue
-  \ifx\@empty\si@unt@unitarg\@empty\else
-    \ifsi@repeatunits
-      \begingroup
-        \si@out@numfalse
-        \si@fam@setfalse
-        \si@fam@set
-        \si@unt@printunit{\si@unt@unitarg}%
-      \endgroup
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%
-%\subsection{Formatting angles}
-%\begin{macro}{\ang}
-%\doarg{keyval options}
-%\darg{angle, either in decimal or deg;min;sec format}
-% The approach used here is similar to that in \SIstyle, but has been
-% modified in a few ways.
-%    \begin{macrocode}
-\si@newrobustcmd*{\ang}[2][]{%
-  \begingroup
-    \sisetup{#1}%
-    \si@fam@mode
-    \si@log@debug{Processing \string\ang\space input `#2'}%
-    \@makeother{\;}%
-    \makeatletter
-    \scantokens{\si@ang@parse#2;;;\@nil}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ang@parse}
-% With the correct catcodes in place, processing can take place strip
-% out the semi-colons.  Here, the input must either contain no
-% semi-colons or two semi-colons.
-%    \begin{macrocode}
-\def\si@ang@parse#1;#2;#3;#4\@nil{%
-  \let\ifsi@ang@fixdp\ifsi@fixdp
-  \si@fixdpfalse
-  \si@ifmtarg{#4}
-    {\si@log@debug{Angle argument contains no
-       semi-colons:\MessageBreak decimal angle}%
-     \si@ang@dec{#1}{}{}}
-    {\si@log@debug{Angle argument contains
-       semi-colons:\MessageBreak degree-minute-second angle}%
-     \renewcommand*{\si@tempa}{#4}%
-     \renewcommand*{\si@tempb}{;;}%
-     \ifx\si@tempa\si@tempb\else
-       \ifsi@strictarc
-         \renewcommand*{\si@tempb}{;}%
-         \ifx\si@tempa\si@tempb
-           \si@log@err{Insufficient semi-colons in argument
-             of \string\ang}{The argument of
-             \string\ang\space  must contain either no
-             semi-colons or exactly two}%
-         \else
-           \si@log@err{Excess semi-colons in argument of
-             \string\ang}{The argument of \string\ang\space
-             must contain either no semi-colons or exactly
-             two}%
-         \fi
-       \fi
-     \fi
-     \si@ang@arc{#1}{#2}{#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ang@dec}
-%\begin{macro}{\si@ang@arc}
-% Two tests are needed, in case the input format requires conversion.
-%    \begin{macrocode}
-\newcommand*{\si@ang@dec}{%
-  \let\si@ang@fix\@gobble
-  \ifsi@ang@toarc
-    \expandafter\si@ang@dectoarc
-  \else
-    \sisetup{padangle=none,anglesep=none}\expandafter\si@ang@typeset
-  \fi}
-\newcommand*{\si@ang@arc}{%
-  \let\si@ang@fix\si@ang@arcfix
-  \ifsi@ang@todec
-    \expandafter\si@ang@arctodec
-  \else
-    \expandafter\si@ang@typeset
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@ang@fixdp}
-%\begin{macro}{\si@ang@fix}
-%\begin{macro}{\si@ang@arcfix}
-%\darg{number}
-% A check is needed so that rounding and zero filling are only
-% applied to the seconds of an arc angle.
-%    \begin{macrocode}
-\newif\ifsi@ang@fixdp
-\newcommand*{\si@ang@fix}[1]{}
-\newcommand*{\si@ang@arcfix}[1]{%
-  \renewcommand*{\si@tempa}{second}%
-  \renewcommand*{\si@tempb}{#1}%
-  \ifx\si@tempa\si@tempb
-    \ifsi@ang@fixdp
-      \expandafter\expandafter\expandafter\si@fixdptrue
-    \else
-      \expandafter\expandafter\expandafter\si@fixdpfalse
-    \fi
-  \else
-    \expandafter\si@fixdpfalse
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@ifnum}
-%\darg{number}
-% A test is required to check that the provided data consists of
-% numbers which can actually be processed by \TeX.  This is achieved
-% by using \cs{si@num@ifvalid} with a fixed list of valid
-% characters.
-%    \begin{macrocode}
-\newcommand*{\si@ang@ifnum}[1]{%
-  \begingroup
-    \renewcommand*{\si@numvalid}{0123456789,.+-}%
-    \ifx\@empty#1\@empty
-      \aftergroup\@firstoftwo
-    \else
-      \si@num@ifvalid{#1}
-        {\aftergroup\@firstoftwo}
-        {\aftergroup\@secondoftwo}%
-    \fi
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ang@arctodec}
-%\darg{degrees}
-%\darg{minutes}
-%\darg{seconds}
-% The business end of converting arcs to decimal angles is relatively
-% straight-forward, as it only needs one calculation.  This has to be
-% divided up, so that disaster does not strike if there are empty
-% arguments; a check is also needed for the sign of the angle,
-% so that the maths makes sense.
-%    \begin{macrocode}
-\newcommand*{\si@ang@arctodec}[3]{%
-  \let\si@ang@fix\@gobble
-  \ifnum\si@num@dp>\thr@@\relax
-    \si@num@dp\thr@@\relax
-  \fi
-  \si@fixdptrue
-  \si@ang@ifnum{#1}
-    {\si@ang@ifnum{#2}
-      {\si@ang@ifnum{#3}
-        {\si@tempdima\z@\relax
-         \renewcommand*{\si@tempa}{+}%
-         \ifx\@empty#1\@empty\else
-           \si@tempdima #1pt\relax
-         \fi
-         \ifdim\si@tempdima<\z@\relax
-           \renewcommand*{\si@tempa}{-}%
-         \fi
-         \ifx\@empty#2\@empty\else
-           \si@tempdima\dimexpr\si@tempdima\si@tempa
-             #2pt/60\relax
-         \fi
-         \ifdim\si@tempdima<\z@\relax
-           \renewcommand*{\si@tempa}{-}%
-         \else
-         \fi
-         \ifx\@empty#3\@empty\else
-           \si@tempdima\dimexpr\si@tempdima\si@tempa
-             #3pt/3600\relax
-         \fi
-         \sisetup{numdecimal=.}%
-         \expandafter\si@ang@typeset\expandafter{%
-           \strip@pt\si@tempdima}{}{}}
-        {\si@ang@notnum{#1}{#2}{#3}}}
-      {\si@ang@notnum{#1}{#2}{#3}}}
-    {\si@ang@notnum{#1}{#2}{#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ang@dectoarc}
-%\begin{macro}{\si@ang@arcdeg}
-%\begin{macro}{\si@ang@arcmin}
-%\begin{macro}{\si@ang@arcsec}
-%\darg{number}
-% The conversion macros for decimal to arc angles.  Life is more
-% complex here than above, even without the need for checks on the
-% input.  A number of separation steps are needed, each of which
-% needs a separate macro.
-%    \begin{macrocode}
-\newcommand*{\si@ang@dectoarc}[1]{%
-  \let\si@ang@fix\si@ang@arcfix
-  \si@ang@fixdptrue
-  \ifnum\si@num@dp>\@ne\relax
-    \si@num@dp\@ne\relax
-  \fi
-  \si@ang@ifnum{#1}
-    {\si@tempdima\z@\relax
-     \ifx\@empty#1\@empty\else
-       \si@tempdima #1pt\relax
-     \fi
-     \si@ang@sepint{deg}%
-     \si@tempdima\dimexpr\si@tempdima *60\relax
-     \si@ang@sepint{min}%
-     \edef\si@tempa{\the\dimexpr\si@tempdima *60\relax}%
-     \expandafter\newcommand\expandafter*\expandafter{%
-       \expandafter\si@ang@arcsec\expandafter}\expandafter{%
-       \expandafter\si@ang@strippt\si@tempa}%
-%    \end{macrocode}
-% A check is made for ``0.0'' seconds, which should be converted to
-% simply ``0''.
-%    \begin{macrocode}
-     \si@tempdima\z@\relax
-     \edef\si@tempa{\the\si@tempdima}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-       \expandafter\si@tempa\expandafter}\expandafter{%
-       \expandafter\si@ang@strippt\si@tempa}%
-     \ifx\si@tempa\si@ang@arcsec
-       \renewcommand*{\si@ang@arcsec}{0}%
-     \fi
-%    \end{macrocode}
-% To avoid adding zeros where they are not required, each part of the
-% angle is now checked.
-%    \begin{macrocode}
-     \renewcommand*{\si@tempa}{0}%
-     \ifx\si@ang@arcdeg\si@tempa
-       \si@temptoks{{}}%
-     \else
-       \si@temptoks{{\si@ang@arcdeg}}%
-     \fi
-     \ifx\si@ang@arcmin\si@tempa
-       \si@temptoks\expandafter{\the\si@temptoks{}}%
-     \else
-       \si@temptoks\expandafter{\the\si@temptoks{%
-         \si@ang@arcmin}}%
-     \fi
-     \ifx\si@ang@arcsec\si@tempa
-       \si@temptoks\expandafter{\the\si@temptoks{}}%
-     \else
-       \si@temptoks\expandafter{\the\si@temptoks{%
-         \si@ang@arcsec}}%
-     \fi
-     \expandafter\si@ang@typeset\the\si@temptoks}
-    {\si@ang@notnum{#1}{}{}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@sepint}
-%\begin{macro}{\si@ang@sint}
-%\begin{macro}{\si@ang@strippt}
-%\darg{either \texttt{deg} or \texttt{min}}
-% Support macros for the conversion from decimal to arc angles.
-%    \begin{macrocode}
-\newcommand*{\si@ang@sepint}[1]{%
-  \expandafter\si@ang@sint\the\si@tempdima\@empty
-  \expandafter\let\csname si@ang@arc#1\endcsname\si@tempa}
-\def\si@ang@sint#1.#2\@empty{%
-  \renewcommand*{\si@tempa}{#1}%
-  \si@tempdima 0.#2\relax}
-\begingroup
-  \catcode`P=12
-  \catcode`T=12
-  \lowercase{
-    \renewcommand*{\si@tempa}{%
-      \def\si@ang@strippt##1PT{##1}}}
-  \expandafter\endgroup
-\si@tempa
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@notnum}
-%\darg{degrees}
-%\darg{minutes}
-%\darg{seconds}
-% Not a \TeX\ number: complain.
-%    \begin{macrocode}
-\newcommand*{\si@ang@notnum}[3]{%
-  \si@log@warn{Angle `#1;#2;#3' is not a pure
-    number:\MessageBreak output will be as given}%
-  \si@ang@typeset{#1}{#2}{#3}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@ang@sign}
-% A flag is needed to leave signs along for angles, where
-% a zero value may still need a sign.
-%    \begin{macrocode}
-\newif\ifsi@ang@sign
+\cs_set_protected_nopar:Npn \_siunitx_number_process_uncertainty_pad: {
+  \intexpr_while_do:nNnn
+    { \int_use:N  \_l_siunitx_process_uncertainty_int }
+      < { \int_use:N \_l_siunitx_process_decimal_int }
+    {
+      \tl_put_right:Nn \_l_siunitx_uncertainty_decimal_tl {0} 
+      \int_incr:N \_l_siunitx_process_uncertainty_int
+    }
+  \tl_put_right:NV \_l_siunitx_uncertainty_decimal_tl 
+    \_l_siunitx_tmpa_tl
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@ang@typeset}
-%\darg{degrees}
-%\darg{minutes}
-%\darg{seconds}
-% The \cs{si@ang@set} macro does the work of assigning the degrees,
-% minutes and seconds, and actually typesetting the result.
-%    \begin{macrocode}
-\newcommand*{\si@ang@typeset}[3]{%
-%    \end{macrocode}
-%\begin{macro}{\si@ang@degs}
-%\begin{macro}{\si@ang@mins}
-%\begin{macro}{\si@ang@secs}
-% First, the three macros that will contain the measures must exist.
+%\begin{macro}{\_siunitx_number_process_uncertainty_separate:}
+%\begin{macro}{\_siunitx_number_process_uncertainty_separate_aux:N}
+% Find the integer--decimal boundary and work appropriately.
 %    \begin{macrocode}
-  \ifsi@ang@padlarge
-    \newcommand*{\si@ang@degs}{0\si@sym@degree}%
-    \newcommand*{\si@ang@mins}{0\si@sym@minute}%
-    \newcommand*{\si@ang@secs}{0\si@sym@second}%
-  \else
-    \newcommand*{\si@ang@degs}{}%
-    \newcommand*{\si@ang@mins}{}%
-    \newcommand*{\si@ang@secs}{}%
-  \fi
-%    \end{macrocode}
-%\begin{macro}{\si@ang@decimalsymbol}
-% The current definition of \cs{si@decimalsymbol} needs to be saved.
-%    \begin{macrocode}
-  \protected@edef\si@ang@decimalsymbol{\si@decimalsymbol}%
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_uncertainty_separate: {
+  \tl_map_function:NN \_l_siunitx_tmpa_tl 
+    \_siunitx_number_process_uncertainty_separate_aux:N
+}
+\cs_set_protected:Npn 
+  \_siunitx_number_process_uncertainty_separate_aux:N #1 {
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_process_uncertainty_int }
+      > { \int_use:N \_l_siunitx_process_decimal_int } 
+    { \tl_put_right:Nn \_l_siunitx_uncertainty_integer_tl {#1} }
+    { \tl_put_right:Nn \_l_siunitx_uncertainty_decimal_tl {#1} }
+  \int_decr:N \_l_siunitx_process_uncertainty_int
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@ang@movesign}
-% Either the signs need to be moved, or this needs to be killed off.
+%\end{macro}
+%\begin{macro}{\_siunitx_number_process_uncertainty_integer:n}
+% Relatively easy: the uncertainty is in the integer part of the number,
+% and so there is no need to generate zeros.
 %    \begin{macrocode}
-  \ifsi@astroang
-    \let\si@ang@movesign\si@ang@astrosign
-  \else
-    \let\si@ang@movesign\@gobble
-  \fi
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_uncertainty_integer:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -uncertainty }
+    \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -uncertainty-integer }
+    \_l_siunitx_tmpa_tl
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@ang@secnum}
-%\begin{macro}{\si@ang@minnum}
-% The arguments are now examined in reverse order.  If they are
-% empty, then nothing is done.  Otherwise, the larger measures are
-% zero-filled, if this has been requested. Some steps are needed
-% to allow for addition of signs to numbers.
+%
+%\begin{macro}{\_siunitx_number_process_zero_fill:}
+%\begin{macro}[aux]{\_siunitx_number_process_zero_fill_aux:n}
+%\begin{macro}[aux]{\_siunitx_number_process_zero_fill_aux:nn}
+% Checks for adding zeros to each component are carried out. The nesting 
+% here makes checking the appropriate flag a little more efficient.
 %    \begin{macrocode}
-  \newcommand*{\si@ang@secnum}{\si@ang@num{second}}%
-  \newcommand*{\si@ang@minnum}{\si@ang@num{minute}}%
-   \si@ifnotmtarg{#3}
-     {\si@log@debug{Found seconds `#3'}%
-      \si@ang@ifnum{#3}
-        {\ifdim #3 pt=\z@\relax\else
-           \si@ang@signtrue
-         \fi}{}%
-      \renewcommand*{\si@ang@secs}
-       {\si@ang@secnum{#3}\si@sym@second}%
-      \renewcommand*{\si@ang@mins}
-        {\si@ang@pad{0\si@sym@minute}}%
-      \renewcommand*{\si@ang@degs}
-        {\si@ang@pad{0\si@sym@degree}}}%
-   \si@ifnotmtarg{#2}
-     {\si@log@debug{Found minutes `#2'}%
-      \si@ang@ifnum{#2}
-        {\ifdim #2 pt=\z@\relax\else
-           \si@ang@signtrue
-         \fi}{}%
-      \renewcommand*{\si@ang@secnum}{%
-        \si@ang@signlessnum{second}}%
-      \renewcommand*{\si@ang@mins}
-       {\si@ang@minnum{#2}\si@sym@minute}%
-      \renewcommand*{\si@ang@degs}
-        {\si@ang@pad{0\si@sym@degree}}}%
-   \si@ifnotmtarg{#1}
-     {\si@log@debug{Found degrees `#1'}%
-      \renewcommand*{\si@ang@secnum}{%
-        \si@ang@signlessnum{second}}%
-      \renewcommand*{\si@ang@minnum}{%
-        \si@ang@signlessnum{minute}}%
-      \renewcommand*{\si@ang@degs}
-%    \end{macrocode}
-% The group here is needed to get the mechanism to move the symbol to
-% work properly.
-%    \begin{macrocode}
-       {\si@ang@num{degree}{#1}%
-        \si@sym@degree}}%
-   \si@out@num
-     {\si@ang@degs\si@anglesep\si@ang@mins\si@anglesep
-        \si@ang@secs}%
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% The group opened by \cs{ang} is closed.
-%    \begin{macrocode}
-   \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@pad}
-%\darg{number}
-% Padding is only added if requested; the zero is a literal.
-%    \begin{macrocode}
-\newcommand*{\si@ang@pad}[1]{\ifsi@ang@padsmall #1\fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@ang@num}
-%\begin{macro}{\si@ang@signlessnum}
-%\darg{one of \texttt{degree}, \texttt{minute} or \texttt{second}}
-%\darg{number}
-% Modified versions of \cs{num}, one to typeset angles without a
-% leading sign and the other with.
-%    \begin{macrocode}
-\newcommand*{\si@ang@num}[2]{%
-  \begingroup
-    \si@ang@fix{#1}%
-    \si@ang@movesign{#1}%
-    \si@num{#2}%
-  \endgroup}
-\newcommand*{\si@ang@signlessnum}[2]{%
-  \begingroup
-    \si@ang@fix{#1}%
-    \si@ang@movesign{#1}%
-    \sisetup{addsign=none}%
-    \si@num{#2}%
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@killdegree}
-%\begin{macro}{\si@ang@killminute}
-%\begin{macro}{\si@ang@killsecond}
-% A mechanism is needed to handle moving the angle unit signs for the
-% \opt{astroang} option.  First, some support macros are needed.
-%    \begin{macrocode}
-\newcommand*{\si@ang@killdegree}{\let\si@sym@degree\relax}
-\newcommand*{\si@ang@killminute}{\let\si@sym@minute\relax}
-\newcommand*{\si@ang@killsecond}{\let\si@sym@second\relax}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@ang@astrosign}
-%\darg{one of \texttt{degree}, \texttt{minute} or \texttt{second}}
-% The method needs two steps, producing the sign over the decimal
-% sign and preventing duplicate symbols appearing. This is based on a
-% suggestion from Morten H{\o}gholm, but using \TeX\ internals as
-% \cs{makebox} does not work here.  Note the need to correct for
-% \cs{scriptspace} (thanks to Donald Arseneau for that).
-%    \begin{macrocode}
-\newcommand*{\si@ang@astrosign}[1]{%
-  \renewcommand*{\si@decimalsymbol}{%
-    \setbox\si@tempboxa=\hbox{%
-      \ensuremath{{\si@ang@decimalsymbol}}}%
-    \si@tempdima\wd\si@tempboxa\relax
-    \setbox\si@tempboxb=\hbox to\z@{%
-      \hss\unhbox\si@tempboxa\hss}%
-    \setbox\si@tempboxa=\hbox{%
-      \csname si@sym@#1\endcsname\hskip-\scriptspace}%
-    \si@tempdimb\wd\si@tempboxa\relax
-    \setbox\si@tempboxc=\hbox to\z@{%
-      \hss\unhbox\si@tempboxa\hss}%
-    \setbox\si@tempboxd=\hbox{%
-      \usebox\si@tempboxb\usebox\si@tempboxc}%
-    \ifdim\si@tempdima>\si@tempdimb\relax
-      \setbox\si@tempboxa=\hbox to\si@tempdima{%
-        \hss\unhbox\si@tempboxd\hss}%
-    \else
-      \setbox\si@tempboxa=\hbox to\si@tempdimb{%
-        \hss\unhbox\si@tempboxd\hss}%
-    \fi
-    \usebox\si@tempboxa%
-    \ifdim\si@tempdima>\si@tempdimb\relax\else
-      \hskip\scriptspace
-    \fi}%
-  \renewcommand*{\si@num@decimalhook}{\expandafter\aftergroup
-    \csname si@ang@kill#1\endcsname}}%
+\cs_set_protected_nopar:Npn \_siunitx_number_process_zero_fill: {
+  \_siunitx_number_process_zero_fill_aux:n { integer }
+  \_siunitx_number_process_zero_fill_aux:n { decimal }
+}
+\cs_set_nopar:Npn \_siunitx_number_process_zero_fill_aux:n #1 {
+  \bool_if:cT { _l_siunitx_process_ #1 _zero_bool } 
+    {
+      \_siunitx_number_process_zero_fill_aux:nn { mantissa } {#1}
+      \_siunitx_number_process_zero_fill_aux:nn { complex }  {#1}
+      \_siunitx_number_process_zero_fill_aux:nn { exponent } {#1}
+    }
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_process_zero_fill_aux:nn #1#2 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 -decimal-marker } 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 - #2 } 
+        { \prop_put:Nnn \_l_siunitx_number_in_prop { #1 - #2 } { 0 } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%\end{macro}
+%\end{macro}
 %
-%\subsection{Tabular material}
-% The automatic formatting and alignment of numerical data in columns
-% is handled here.  The various other packages that work in this area
-% are basically ripped-off here.  The letters |D|, |N| and |R| are
-% already taken by the other packages for numerical alignment, and so
-% |S| ($=$ \currpkg) is chosen for the alignment of numerical
-% material.  The package also provides a second column type, |s|, for
-% units (the letter is taken from \cs{si}).
-%
-%\begin{macro}{\NC@list}
-%\changes{v1.1e}{2008/11/18}{Fixed issue with \pkg{cellspace} package}
-% The first part of the job is to create the basic apparatus for the
-% columns using the \pkg{array} package.  To prevent any issues with
-% the content of optional arguments to the new columns, so
-% rearrangement is needed.  The \currpkg columns have to come
-% \emph{before} any other column definitions.  This is achieved by
-% saving \cs{NC@list}, creating the columns then restoring the list
-% with the appropriate extra parts.
-%    \begin{macrocode}
-\@ifpackageloaded{cellspace}
-  {\newcolumntype{C}[1]{>{\bcolumn #1\@nil}#1<{\ecolumn}}}
-  {\AtBeginDocument{
-    \@ifpackageloaded{cellspace}
-     {\newcolumntype{C}[1]{>{\bcolumn #1\@nil}#1<{\ecolumn}}%
-      \renewcommand*{\NC@rewrite@S}[1][]{%
-        \edef\si@tempa{\the\@temptokena
-        >{\noexpand\si@tab@begin@S[#1]}c%
-        <{\noexpand\si@tab@end@S}}%
-        \@temptokena\expandafter{\si@tempa}%
-        \NC@find}}
-     {}}}
-\edef\si@tempa{%
-  \noexpand\NC@do S\noexpand\NC@do s\the\NC@list}
-\newcolumntype{S}{}
-\newcolumntype{s}{}
-\NC@list\expandafter{\si@tempa}
-%    \end{macrocode}
-%\end{macro}
-%\changes{v1.1h}{2008/11/30}{Fixed problem with \pkg{colortbl} package}
-%\changes{v1.1i}{2008/11/30}{Better solution to \pkg{colortbl} issue}
-%\begin{macro}{\si@tab@corr@colortbl}
-% A correction if \pkg{colortbl} is loaded.
-%    \begin{macrocode}
-\newcommand*{\si@tab@corr@colortbl}{\relax}
-\AtBeginDocument{
-  \@ifpackageloaded{colortbl}{%
-    \renewcommand*{\si@tab@corr@colortbl}{%
-      \hskip\stretch{-0.5}\kern\z@
-    }
-  }{}
-}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\NC@rewrite@S}
-%\begin{macro}{\NC@rewrite@s}
-%\doarg{keyval options}
-% Following the \numprint approach, the \cs{NC@rewrite@\ldots} macros
-% are rewritten to collect the cell contents.  This means messing
-% with the internal macros of another package, but there is no other
-% way to do this.  As \pkg{array} is a standard package from the
-% \pkg{tools} bundle, this should be reasonably safe. Here the begin
-% and end code needed is added to the existing list if
-% \cs{@temptokena}, with the start and end macros unexpanded.
-% Argument |#1| contains any user setup options for this column.
-% Passing an argument at this stage will cause issues, so each column
-% type needs its own \texttt{begin} and \texttt{end} macros.
-%    \begin{macrocode}
-\renewcommand*{\NC@rewrite@S}[1][]{%
-  \edef\si@tempa{\the\@temptokena
-    >{\noexpand\si@tab@begin@S[#1]}c%
-    <{\noexpand\si@tab@end@S}}%
-  \@temptokena\expandafter{\si@tempa}%
-  \NC@find}
-\renewcommand*{\NC@rewrite@s}[1][]{%
-  \edef\si@tempa{\the\@temptokena
-    >{\noexpand\si@tab@begin@s[#1]}c%
-    <{\noexpand\si@tab@end@s}}%
-  \@temptokena\expandafter{\si@tempa}%
-  \NC@find}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@begin@S}
-%\begin{macro}{\si@tab@begin@s}
-%\begin{macro}{\si@tab@gettok}
-%\doarg{keyval options}
-% At this stage, the appropriate token gathering macro is activated,
-% and the common starting macro is called.  For the |S| column, the
-% \opt{seperr} is turned off, and an error is set to be raised by any
-% ``x-part'' input.
-%    \begin{macrocode}
-\newcommand*{\si@tab@begin@S}[1][]{%
-  \si@log@debug{Processing S column cell contents}%
-  \let\si@tab@gettok\si@tab@gettok@S
-  \si@seperrfalse
-  \renewcommand*{\si@num@sepxpart}{%
-    \si@log@err{Multiple numbers not allowed in
-       tables\MessageBreak Only the first number used}
-       \@ehb}%
-  \si@tab@begin[#1]}
-\newcommand*{\si@tab@begin@s}[1][]{%
-  \si@log@debug{Processing s column cell contents}%
-  \let\si@tab@gettok\si@tab@gettok@s
-  \si@tab@begin[#1]}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@toks}
-%\begin{macro}{\si@tab@pretoks}
-%\begin{macro}{\si@tab@posttoks}
-% Some storage is needed for the data to build up.  In common with
-% \pkg{rccol} and \numprint, token registers are used for this (thus
-% leaving problematic input to be handled later).
-%    \begin{macrocode}
-\newtoks\si@tab@toks
-\newtoks\si@tab@pretoks
-\newtoks\si@tab@posttoks
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@begin}
-%\doarg{keyval options}
-% The macro for gathering up input is common to both column types. It
-% uses the method for \pkg{rccol}; the cell contents are collected by
-% a second macro, which then stores all of the data in an appropriate
-% token store.
-%    \begin{macrocode}
-\newcommand*{\si@tab@begin}[1][]{%
-  \begingroup
-    \sisetup{#1}%
-    \si@tab@toks{}%
-    \si@tab@pretoks{}%
-    \si@tab@posttoks{}%
-    \si@switchfalse
-    \si@tab@gettok}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@next}
-% A macro is needed for recursion when collecting cell contents.
-%    \begin{macrocode}
-\newcommand*{\si@tab@next}{}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@gettok@S}
-%\changes{v1.0j}{2008/08/21}{Token gathering code now checks for
-%  expandable content}
-%\darg{token}
-% The cell-content collection system is inherited from \pkg{rccol}.
-% First, the current input is compared with a fixed list of macros
-% which need custom handling.
-%    \begin{macrocode}
-\newcommand*{\si@tab@gettok@S}[1]{%
-  \ifx\tabularnewline#1\relax
-    \let\si@tab@next\si@tab@newline@S
-  \else
-    \ifx\end#1\relax
-      \let\si@tab@next\end
-    \else
-      \ifx\si@tab@end@S#1\relax
-        \let\si@tab@next\si@tab@end@S
-      \else
-        \ifx\endtabular#1\relax
-          \let\si@tab@next\endtabular
-        \else
-          \ifx\csname#1\relax
-            \let\si@tab@next\csname
-          \else
-            \ifx\relax#1\relax
-              \let\si@tab@next\relax
-            \else
-%    \end{macrocode}
-% If the code gets to here, then recursion should occur.
-%    \begin{macrocode}
-              \let\si@tab@next\si@tab@gettok@S
-%    \end{macrocode}
-% Cells always contain \cs{ignorespaces} and \cs{unskip}. These can
-% both be filtered out here and are saved to either the pre-number or
-% post-number token store, as appropriate. This is done without
-% fixing the destination in case the user adds addition copies to the
-% input.
-%    \begin{macrocode}
-              \ifx\ignorespaces#1\relax
-                \si@tab@othertok{#1}%
-              \else
-                \ifx\unskip#1\relax
-                  \si@tab@othertok{#1}%
-                \else
-%    \end{macrocode}
-% If the current token is a valid numerical character, then the flag
-% is set and the input is saved into the ``processing'' token
-% register.
-%    \begin{macrocode}
-                  \si@str@ifchrstr{#1}{\si@numvalid}
-                     {\si@switchtrue
-                      \si@log@debug{Found numerical cell
-                        contents `#1'}%
-                      \si@tab@toks=\expandafter{%
-                        \the\si@tab@toks#1}}
-%    \end{macrocode}
-% For non-numerical content, some testing is needed. A check is made
-% to see if the current ``token'' is a single item. If it was wrapped
-% in one set of braces before being picked up here, they will have
-% been removed. So the input may now have more than one character to
-% it. If it is a single token, testing for expandability first
-% requires a check for another set of braces.  This is handed off
-% using \cs{futurelet}.
-%    \begin{macrocode}
-                     {\si@tab@ifonechar{#1}
-                       {\futurelet\si@tempa\si@tab@bracetest#1}%
-                       {\si@tab@othertok{#1}}}%
-                \fi
-              \fi
-            \fi
-          \fi
-        \fi
-      \fi
-    \fi
-  \fi
-  \si@tab@next}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@othertok}
-%\changes{2009/12/25}{v1.3g}{Fix for multiple tokens in input}
-%\changes{2010/021/21}{v1.4b}{Back to plan A}
-%\darg{token}
-%\begin{macro}{\si@tab@othertok@aux}
-% Tokens which are not part of a number can occur before or after a
-% number. This is all sorted out here, with some debugging
-% information for good measure.
-%    \begin{macrocode}
-\newcommand*{\si@tab@othertok}[1]{%
-  \si@log@debug{Found other cell contents `\unexpanded{#1}'}%
-  \ifsi@switch
-    \si@log@debug{Adding to post-numeral part}%
-    \si@tab@posttoks=\expandafter{\the\si@tab@posttoks#1}%
-  \else
-    \si@log@debug{Adding to pre-numeral part}%
-    \si@tab@pretoks=\expandafter{\the\si@tab@pretoks#1}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@ifonechar}
-%\darg{token}
-%\begin{macro}{\si@tab@onechar}
-% A quick check for a single character.
-%    \begin{macrocode}
-\newcommand*{\si@tab@ifonechar}[1]{\si@tab@onechar#1\@empty}
-\def\si@tab@onechar#1#2\@empty{%
-  \ifx\@empty#2\@empty
-    \expandafter\@firstoftwo
-  \else
-    \expandafter\@secondoftwo
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@bracetest}
-% For the \cs{futurelet} test, a separate macro is needed. If the
-% current token starts with a brace, then it is added to the
-% ``other'' stack.  If not, a test can be made on its definition.
-%    \begin{macrocode}
-\newcommand*{\si@tab@bracetest}{%
-  \ifx\si@tempa\bgroup
-    \expandafter\si@tab@othertok
-  \else
-    \expandafter\si@tab@exptest
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@exptest}
-%\changes{2009/12/25}{v1.3g}{Check dor \LaTeXe\ robust commands}
-%\begin{macro}{\si@tab@exptest@aux}
-%\begin{macro}{\si@tab@meaning}
-%\begin{macro}{\si@tab@strip}
-%\darg{token}
-% The meaning of the token is compared to that for a short macro. If
-% the two are of the same type, expansion is attempted. In this case,
-% the current pre-number tokens are also typeset.
-%    \begin{macrocode}
-\newcommand*{\si@tab@exptest}[1]{%
-  \edef\si@tempa{\si@tab@meaning{#1}}%
-  \ifx\si@tempa\si@tab@macro
-    \expandafter\si@tab@exptest@aux
-  \else
-    \expandafter\si@tab@othertok
-  \fi
-  {#1}%
-}
-\newcommand*{\si@tab@exptest@aux}[1]{%
-  \ifcsname\expandafter\@gobble\string#1 \endcsname
-    \si@tab@othertok{#1}%
-  \else
-    \si@log@debug{Expanding cell contents `\unexpanded{#1}'}%
-    \the\si@tab@pretoks
-    \si@tab@pretoks{}%
-    \protected@edef\si@tab@next{\noexpand\si@tab@gettok@S#1}%
-  \fi
-}
-\newcommand*{\si@tab@meaning}[1]{%
-  \expandafter\si@tab@strip\meaning#1:->:->\@empty}
-\def\si@tab@strip#1:->#2:->#3\@empty{#1}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@macro}
-% A supporter macro for the above which always expands to ``macro''
-% with everything with category code 12.
-%    \begin{macrocode}
-\newcommand*{\si@tab@macro}{}
-\edef\si@tab@macro{\si@tab@meaning{\si@tab@macro}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@gettok@s}
-%\changes{v1.0a}{2008/06/20}{Fixed issues with alignment of
-%  \texttt{s} column contents}
-%\darg{token}
-% The situation for the |s| column is less complex, as there is only
-% one store and expansion is not an issue.
-%    \begin{macrocode}
-\newcommand*{\si@tab@gettok@s}[1]{%
-  \ifx\tabularnewline#1\relax
-    \let\si@tab@next\si@tab@newline@s
-  \else
-    \ifx\end#1\relax
-      \let\si@tab@next\end
-    \else
-      \ifx\si@tab@end@s#1\relax
-        \let\si@tab@next\si@tab@end@s
-      \else
-        \ifx\endtabular#1\relax
-          \let\si@tab@next\endtabular
-        \else
-          \ifx\csname#1\relax
-            \let\si@tab@next\csname
-          \else
-            \ifx\relax#1\relax
-              \let\si@tab@next\relax
-            \else
-              \let\si@tab@next\si@tab@gettok@s
-              \ifx\ignorespaces#1\relax\else
-                \ifx\unskip#1\relax\else
-                  \si@tab@toks=\expandafter{%
-                    \the\si@tab@toks#1}%
-                  \si@log@debug{Found cell contents `#1'}%
-                \fi
-              \fi
-            \fi
-          \fi
-        \fi
-      \fi
-    \fi
-  \fi
-  \si@tab@next}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@end@S}
-%\changes{v1.0a}{2008/06/20}{Fixed mixed number/text column
-%  alignment}
-%\changes{v1.0k}{2008/09/02}{Fixed problem with coloured cells}
-%\begin{macro}{\si@tab@rfill}
-%\begin{macro}{\si@tab@lfill}
-%\begin{macro}{\si@tab@end@s}
-% The end macros are similar, but with some minor differences. In
-% both cases, the appropriate filling is carried out.  For the |S|
-% column, this depends on the cell contents, whereas for the |s|
-% column the fill is always the same.  Output of a number in an |S|
-% column is only attempted if one was found, otherwise the cell
-% contents will all be in \cs{si@tab@pretoks}.
-%    \begin{macrocode}
-\newcommand*{\si@tab@end@S}{%
-    \ifsi@switch
-      \let\si@tab@lfill\si@tab@lfill@S
-      \let\si@tab@rfill\si@tab@rfill@S
-    \else
-      \let\si@tab@rfill\si@tab@rfill@t
-      \let\si@tab@lfill\si@tab@lfill@t
-    \fi
-    \si@tab@corr@colortbl
-    \hskip\stretch{\si@tab@lfill}\kern\z@
-    \ifsi@switch
-      \the\si@tab@pretoks
-      \si@tab@numout
-      \the\si@tab@posttoks
-    \else
-      \the\si@tab@pretoks
-    \fi
-    \hskip\stretch{\si@tab@rfill}\kern\z@
-    \si@tab@corr@colortbl
-  \endgroup}
-\newcommand*{\si@tab@end@s}{%
-    \si@tab@corr@colortbl
-    \hskip\stretch{\si@tab@lfill@s}\kern\z@ 
-    \ignorespaces
-    \expandafter\si\expandafter{\the\si@tab@toks}%
-    \unskip
-    \hskip\stretch{\si@tab@rfill@s}\kern\z@ 
-    \si@tab@corr@colortbl
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@newline@S}
-%\begin{macro}{\si@tab@newline@s}
-%\begin{macro}{\si@tab@end}
-% If the column is the final one read, then some work is needed with
-% the \cs{tabularnewline} macro.  Output has to happen \emph{before}
-% the new line, then the ending macro is made safe before calling the
-% \LaTeX\ line end.  If the user makes use of the primitive \cs{cr}
-% then this problem does not arise as \cs{si@tab@end@\ldots} is
-% called correctly.
-%    \begin{macrocode}
-\newcommand*{\si@tab@newline@S}{%
-  \si@tab@end@S
-  \hfil\relax
-  \let\si@tab@end\si@tab@end@S
-  \renewcommand*{\si@tab@end@S}{\let\si@tab@end@S\si@tab@end}%
-  \tabularnewline}
-\newcommand*{\si@tab@newline@s}{%
-  \si@tab@end@s
-  \hfil\relax
-  \let\si@tab@end\si@tab@end@s
-  \renewcommand*{\si@tab@end@s}{\let\si@tab@end@s\si@tab@end}%
-  \tabularnewline}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%
-%\begin{macro}{\si@tempcnta}
-%\begin{macro}{\si@tempcntb}
-% The second part of the tabular code is concerned with typesetting
-% numbers in |S| columns with the appropriate alignment. Counters are
-% needed for the digit-counting system.
-%    \begin{macrocode}
-\newcount\si@tempcnta
-\newcount\si@tempcntb
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@numout}
-%\changes{v1.1}{2008/09/03}{Extended for non-aligned output}
-% If a number is found, then some secondary processing is needed to
-% format it correctly.
-%    \begin{macrocode}
-\newcommand*{\si@tab@numout}{%
-  \si@num@intabtrue
-  \ifsi@tabparseonly\else
-    \ifsi@tab@fixed
-      \ifsi@tabautofit
-        \si@num@dp\si@tab@mantpostcnt\relax
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter\si@fixdptrue
-      \fi
-    \fi
-  \fi
-  \expandafter\si@num\expandafter{\the\si@tab@toks}%
-  \si@tab@format}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@prebox}
-%\begin{macro}{\si@tab@postbox}
-%\begin{macro}{\si@tab@midbox}
-%\begin{macro}{\si@tab@expbox}
-% The various boxes needed for the column centring are declared
-% Unlike the \pkg{dcolumn} original, private boxes are used here.
-% \cs{si@tempboxa} is used when a space to measure one of the
-% constituents is needed; it is never used for output.
-%    \begin{macrocode}
-\newbox\si@tab@prebox
-\newbox\si@tab@midbox
-\newbox\si@tab@postbox
-\newbox\si@tab@expbox
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@format}
-%\changes{v1.1}{2008/09/03}{Extended for non-aligned output}
-% The formatting set up is taken from \pkg{dcolumn}, but with
-% control of the output form the stored information.  The choice
-% of a variable (decimal-centred) column or fixed width boxes is
-% made.
-%    \begin{macrocode}
-\newcommand*{\si@tab@format}{%
-  \ifsi@tabparseonly
-    \expandafter\si@tab@outonly
-  \else
-    \ifsi@tab@fixed
-      \expandafter\expandafter\expandafter\si@tab@fixed
-    \else
-      \expandafter\expandafter\expandafter\si@tab@unfixed
-    \fi
-  \fi
-%    \end{macrocode}
-% A hack to get the correct colour everywhere without too much work.
-%    \begin{macrocode}
-  \ifsi@colourvalues
-    \si@fam@colourcmd{\si@valuecolour}%
-  \fi
-  \box\si@tab@prebox\box\si@tab@midbox\box\si@tab@postbox
-    \box\si@tab@expbox}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@outonly}
-% The non-alignment option means that no real processing is done: only font
-% control is required.
-%    \begin{macrocode}
-\newcommand*{\si@tab@outonly}{%
-  \si@log@debug{Using non-aligned S column}%
-  \setbox\si@tab@prebox=\hbox{}%
-  \setbox\si@tab@midbox=\hbox{}%
-  \setbox\si@tab@postbox=\hbox{}%
-  \setbox\si@tab@expbox=\hbox{}%
-    \protected@edef\si@tempa{%
-      \si@tab@out
-    \ifx\@empty\si@num@out\@empty\else
-      \ensuremath{{\si@decimalsymbol}}%
-    \fi
-    \si@num@out
-    \si@tab@expout}%
-  \expandafter\si@out@num\expandafter{\si@tempa}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@unfixed}
-%\changes{v1.0l}{2008/09/03}{Fixed issue with decimal sign and
-%  integers}
-%\changes{v1.2e}{2009/02/04}{Various \cs{expandafter}s removed:
-%  lead to a bug with \opt{textmode} option}
-% When the width of the contents is not fixed, the system creates a
-% block in which the decimal marker is always at the centre. This is
-% achieved by placing the pre- and post-decimal parts of the number
-% in boxes.  The wider one is then used to set up the column width,
-% by resizing the other one.
-%    \begin{macrocode}
-\newcommand*{\si@tab@unfixed}{%
-  \si@log@debug{Using variable width S column}%
-  \ifx\@empty\si@num@out\@empty
-    \setbox\si@tab@midbox=\hbox
-      {\phantom{\ensuremath{{\si@decimalsymbol}}}}%
-  \else
-    \setbox\si@tab@midbox=\hbox
-      {\ensuremath{{\si@decimalsymbol}}}%
-  \fi
-  \protected@edef\si@num@out{\si@num@out\si@tab@expout}%
-  \setbox\si@tab@prebox=\hbox{\si@out@num{\si@tab@out}}%
-  \setbox\si@tab@postbox=\hbox{\si@out@num{\si@num@out}}%
-  \ifdim\wd\si@tab@prebox>\wd\si@tab@postbox\relax
-    \setbox\si@tab@postbox=\hbox to\wd\si@tab@prebox%
-      {\unhbox\si@tab@postbox\hfill}%
-  \else
-    \setbox\si@tab@prebox=\hbox to\wd\si@tab@postbox%
-      {\hfill\unhbox\si@tab@prebox}%
-  \fi
-  \setbox\si@tab@expbox=\hbox{}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@predim}
-%\begin{macro}{\si@tab@postdim}
-%\begin{macro}{\si@tab@expdim}
-%\begin{macro}{\si@tempdima}
-%\begin{macro}{\si@tempdimb}
-% Some storage dimensions are declared.
-%    \begin{macrocode}
-\newdimen\si@tab@predim
-\newdimen\si@tab@postdim
-\newdimen\si@tab@expdim
-\newdimen\si@tempdima
-\newdimen\si@tempdimb
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@tab@sp}
-% A short macro to control superscript.
-%    \begin{macrocode}
-\newcommand*{\si@tab@sp}{}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@fixed}
-%\changes{v1.0l}{2008/09/03}{Fixed issue with spacing when no digits
-%  present after decimal marker}
-%\changes{v1.2e}{2009/02/04}{Various \cs{expandafter}s removed:
-%  lead to a bug with \opt{textmode} option}
-% The column is not centred on the decimal marker; the user specifies
-% how many characters on each side are allowed for.  First, the width
-% of a character is measured, and stored.
-%    \begin{macrocode}
-\newcommand*{\si@tab@fixed}{%
-  \si@log@debug{Using fixed-width S column}%
-  \let\si@tab@sp\relax
-  \setbox\si@tab@midbox=\hbox{}%
-  \setbox\si@tab@expbox=\hbox{}%
-  \setbox\si@tempboxa=\hbox{\si@out@num{1}}%
-  \si@tempdima\wd\si@tempboxa\relax
-%    \end{macrocode}
-% The width for the two output boxes is set up.
-%    \begin{macrocode}
-  \si@tab@predim\the\si@tab@mantprecnt\si@tempdima\relax
-  \si@tab@sepcorr{mantpre}{pre}%
-  \si@tab@postdim\si@tab@mantpostcnt\si@tempdima\relax
-  \setbox\si@tempboxa=\hbox{\ensuremath{{\si@decimalsymbol}}}%
-  \ifnum\si@tab@mantpostcnt=\z@\relax\else
-    \advance\si@tab@postdim\wd\si@tempboxa\relax
-  \fi
-  \si@tab@sepcorr{mantpost}{post}%
-%    \end{macrocode}
-% If space is needed for an exponent, it needs to be allowed for in
-% the exponent box dimension.  First, the digits of the two parts are
-% checked for; the width of a character is altered to be superscript.
-%    \begin{macrocode}
-  \setbox\si@tempboxa=\hbox{\si@out@num{^{1}}}%
-  \si@tempdima\wd\si@tempboxa\relax
-  \ifnum\si@tab@expprecnt>\z@\relax
-    \si@tab@expdim\si@tab@expprecnt\si@tempdima\relax
-    \si@tab@sepcorr{exppre}{exp}%
-  \fi
-  \let\si@tab@sp\sp
-  \ifnum\si@tab@exppostcnt>\z@\relax
-    \advance\si@tab@expdim\si@tab@exppostcnt\si@tempdima\relax
-    \setbox\si@tempboxa=\hbox{%
-      \ensuremath{^{\si@decimalsymbol}}}%
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-    \si@tab@sepcorr{exppost}{exp}%
-  \fi
-%    \end{macrocode}
-% Space is reserved for signs.
-%    \begin{macrocode}
-  \setbox\si@tempboxa=\hbox{\ensuremath{-}}%
-  \ifsi@tab@mantsign
-    \advance\si@tab@predim\wd\si@tempboxa\relax
-  \fi
-  \setbox\si@tempboxa=\hbox{\ensuremath{^{-}}}%
-  \ifsi@tab@expsign
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-  \fi
-%    \end{macrocode}
-% Now, if there is space to be saved for an exponent under any
-% circumstances, the space for the ``$\times 10$'' part is needed.
-% This is done by adding both counters together, then using this
-% result for the logic.
-%    \begin{macrocode}
-  \si@tempcnta\si@tab@expprecnt\relax
-  \advance\si@tempcnta\si@tab@exppostcnt\relax
-  \ifnum\si@tempcnta>\z@\relax
-    \setbox\si@tempboxa=\hbox{\ensuremath{%
-      {}\si@expproduct{}\si@expbase}}%
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-  \fi
-%    \end{macrocode}
-% Finally for the box dimensions, if the exponent is not aligned,
-% the space reserved for it is added to the post box.
-%    \begin{macrocode}
-  \ifsi@tabalignexp\else
-    \advance\si@tab@postdim\si@tab@expdim\relax
-  \fi
-%    \end{macrocode}
-% With the boxes set up, the contents can be sorted out.  A bit of
-% shuffling may be needed, depending on the treatment of exponents.
-%    \begin{macrocode}
-  \setbox\si@tab@prebox=\hbox to\si@tab@predim{\hss\hfill
-    \si@out@num{\si@tab@out}}%
-  \ifx\@empty\si@num@out\@empty
-    \setbox\si@tab@postbox=\hbox to\si@tab@postdim{\hfil}%
-  \else
-    \ifsi@tabalignexp\else
-      \protected@edef\si@num@out{\si@num@out\si@tab@expout}%
-    \fi
-    \setbox\si@tab@postbox=\hbox to\si@tab@postdim
-      {\ensuremath{{\si@decimalsymbol}}\si@out@num
-        {\si@num@out}\hfil}%
-  \fi
-  \ifx\@empty\si@tab@expout\@empty
-    \ifsi@tabalignexp
-      \setbox\si@tab@expbox=\hbox to\si@tab@expdim{\hfil}%
-    \fi
-  \else
-    \ifsi@tabalignexp
-      \setbox\si@tab@expbox=\hbox to\si@tab@expdim
-        {\si@out@num{\si@tab@expout}\hfil}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@tab@sepcorr}
-%\darg{one of \texttt{mantpre}, \texttt{mantpost}, \texttt{exppre} or
-%  \texttt{exppost}}
-%\darg{one of \texttt{pre}, \texttt{post} or \texttt{exp}}
-% A spacing correction is needed \emph{if} the number of digits to be
-% allowed for will lead to the introduction of a separator.  A counter
-% and dimension are needed for the testing.
-%    \begin{macrocode}
-\newcommand*{\si@tab@sepcorr}[2]{%
-  \expandafter\si@tempcnta\expandafter\the
-    \csname si@tab@#1cnt\endcsname\relax
-%    \end{macrocode}
-% Calculate how many groups of three there are, then allow for not
-% separating four characters if \cs{ifsi@sepfour} is false.
-%    \begin{macrocode}
-  \divide\si@tempcnta\thr@@\relax
-  \ifsi@sepfour\else
-    \expandafter\ifnum\expandafter\the
-      \csname si@tab@#1cnt\endcsname=4\relax
-      \si@tempcnta\z@\relax
-    \fi
-  \fi
-%    \end{macrocode}
-% The width of the separators is measured, and the correct number of
-% separator widths are added to the box dimension.
-%    \begin{macrocode}
-  \setbox\si@tempboxa=\hbox{%
-    \ensuremath{\si@tab@sp{\si@digitsep}}}%
-  \expandafter\advance\csname si@tab@#2dim\endcsname
-    \si@tempcnta\wd\si@tempboxa}
+%\subsection{Formatting numbers for output}
+%
+% Getting numbers ready for printing requires the reconstruction of the
+% number from the various parts processed earlier. Spaces and brackets
+% are added back into the main numbers, as the various parts are also 
+% correctly formatted. The difference between the \texttt{in} and
+% \texttt{out} store is that the later can include formatting such as 
+% hard spaces.
+% 
+%\begin{macro}{\_l_siunitx_number_out_prop}
+% Like the \texttt{in} version!
+%    \begin{macrocode}
+\prop_new:N \_l_siunitx_number_out_prop
+%    \end{macrocode}
+%\end{macro} 
+%
+%\begin{macro}{\_l_siunitx_group_sep_tl}
+%\begin{macro}{\_l_siunitx_output_decimal_tl}
+% A couple of variables are declared here, as they need a little more
+% work than just storage.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_group_sep_tl
+\tl_new:N \_l_siunitx_output_decimal_tl
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_complex_after_bool}
+% A setting for where complex numbers go.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_complex_after_bool
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_brackets_bool}
+%\begin{macro}{\_l_siunitx_bracket_close_tl}
+%\begin{macro}{\_l_siunitx_output_decimal_copy_bool}
+%\begin{macro}{\_l_siunitx_exponent_base_tl}
+%\begin{macro}{\_l_siunitx_exponent_product_tl}
+%\begin{macro}{\_l_siunitx_group_decimal_bool}
+%\begin{macro}{\_l_siunitx_group_four_bool}
+%\begin{macro}{\_l_siunitx_group_integer_bool}
+%\begin{macro}{\_l_siunitx_negative_color_tl}
+%\begin{macro}{\_l_siunitx_bracket_open_tl}
+%\begin{macro}{\_l_siunitx_output_uncert_close_tl}
+%\begin{macro}{\_l_siunitx_output_complex_tl}
+%\begin{macro}{\_l_siunitx_output_uncert_open_tl}
+%\begin{macro}{\_l_siunitx_uncert_sep_bool}
+%\begin{macro}{\_l_siunitx_tight_bool}
+%\begin{macro}{\_l_siunitx_uncert_sep_tl}
+% Lots of settings, some used only for numbers, some more widely.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  bracket-numbers           .bool_set:N = \_l_siunitx_brackets_bool,
+  close-bracket             .tl_set:N   = \_l_siunitx_bracket_close_tl, 
+  complex-root-position     .choice:,
+  complex-root-position
+    / after-number          .code:n     =
+      { \bool_set_true:N \_l_siunitx_complex_after_bool } ,
+  complex-root-position
+    / before-number          .code:n     =
+      { \bool_set_false:N \_l_siunitx_complex_after_bool } ,
+  copy-decimal-marker       .bool_set:N = 
+    \_l_siunitx_output_decimal_copy_bool,
+  exponent-base             .tl_set:N   = \_l_siunitx_exponent_base_tl,
+  exponent-product          .tl_set:N   = 
+    \_l_siunitx_exponent_product_tl,
+  group-decimal-digits      .bool_set:N = 
+    \_l_siunitx_group_decimal_bool,
+  group-digits              .meta:n = 
+    {
+      group-decimal-digits = #1,
+      group-integer-digits = #1
+    },
+  group-four-digits         .bool_set:N = \_l_siunitx_group_four_bool,
+  group-integer-digits      .bool_set:N = 
+    \_l_siunitx_group_integer_bool,
+  group-separator           .code:n     = 
+    {
+      \tl_set:Nn \_l_siunitx_group_sep_tl { {#1} }
+    },
+  negative-color            .tl_set:N   = \_l_siunitx_negative_color_tl,
+  open-bracket              .tl_set:N   = \_l_siunitx_bracket_open_tl, 
+  output-close-uncertainty  .tl_set:N   = 
+    \_l_siunitx_output_uncert_close_tl,
+  output-complex-root       .tl_set:N   = \_l_siunitx_output_complex_tl,
+  output-decimal-marker     .code:n     = 
+    {
+      \tl_set:Nn \_l_siunitx_output_decimal_tl { {#1} }
+    },
+  output-open-uncertainty   .tl_set:N   = 
+    \_l_siunitx_output_uncert_open_tl, 
+  separate-uncertainty      .bool_set:N = \_l_siunitx_uncert_sep_bool,
+  tight-spacing             .bool_set:N = \_l_siunitx_tight_bool,
+  uncertainty-separator     .tl_set:N   = \_l_siunitx_uncert_sep_tl,
+}
+\keys_set:nn { siunitx } { 
+  bracket-numbers           = true, % (
+  close-bracket             = ),
+  complex-root-position     = after-number,
+  copy-decimal-marker       = false,
+  exponent-base             = 10,
+  exponent-product          = \times,
+  group-decimal-digits      = true,
+  group-integer-digits      = true,
+  group-separator           = \,,
+  open-bracket              = (, % ) (
+  output-close-uncertainty  = ),
+  output-complex-root       = \mathrm { i },
+  output-decimal-marker     = .,
+  output-open-uncertainty   = (, % )
+}
+%    \end{macrocode}
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro}
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_number_format:}
+% The master control function for formatting output: the usual set up.
+% The number is put back together in stages. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format: {
+  \prop_if_empty:NF \_l_siunitx_number_in_prop 
+    {
+      \prop_clear:N \_l_siunitx_number_out_prop
+      \_siunitx_number_format_reassemble:
+      \_siunitx_number_format_complex:  
+      \_siunitx_number_format_sign:n { mantissa }
+      \_siunitx_number_format_sign:n { exponent }
+      \_siunitx_number_format_color:
+      \_siunitx_number_format_final:
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %
-%\subsection{Units}
-%\begin{macro}{\SI}
-%\doarg{keyval options}
-%\darg{number}
-% There are two types of user macros for the units system; those for
-% defining new units, prefixes and powers, and those for using them.
-% There are two macros for using units, \cs{SI} and \cs{si}, which
-% work in very similar ways. argument to \cs{SI}
+%\begin{macro}{\_siunitx_number_format_brackets:n}
+%\begin{macro}{\_siunitx_number_format_brackets_aux:n}
+% There are various points at which brackets might be added to
+% avoid ambiguity. The function here adds the appropriate tokens
+% around whatever is in the supplied named store.
 %    \begin{macrocode}
-\si@newrobustcmd*{\SI}[2][]{%
-  \@ifnextchar[%]
-    {\si@SI[#1]{#2}}
-    {\si@SI[#1]{#2}[]}}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_brackets:n #1 {
+  \bool_if:NT \_l_siunitx_brackets_bool 
+    {
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -bracket } 
+        {
+          \_siunitx_number_format_brackets_aux:n {#1}
+          \prop_del:Nn \_l_siunitx_number_out_prop { #1 -bracket }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_brackets_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop { #1 -result } 
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    {
+      \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+    }
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl 
+    \_l_siunitx_bracket_open_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl 
+    \_l_siunitx_bracket_close_tl
+  \tl_if_eq:nnTF {#1} { result } 
+    { \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl }
+    {
+      \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result } 
+        \_l_siunitx_tmpa_tl
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si}
-%\doarg{keyval options}
-%\darg{unit}
-% \cs{si} is just an alias for \cs{SI} with no number; everything is
-% handed off into an internal macro.  The internal macro also handles
-% the optional prefix
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_color:}
+%\begin{macro}{\_siunitx_number_format_color_aux:n}
+% If the mantissa is negative, then any colour for output might change.
 %    \begin{macrocode}
-\si@newrobustcmd*{\si}[2][]{\si@SI[#1]{}[]{#2}}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_color: {
+  \tl_if_empty:NF \_l_siunitx_negative_color_tl 
+    { 
+      \_siunitx_number_format_color_aux:n { mantissa-sign }
+      \_siunitx_number_format_color_aux:n { sign }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_color_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \tl_if_eq:nVT { - } \_l_siunitx_tmpa_tl 
+        {
+           \prop_put:NnV \_l_siunitx_number_out_prop { color } 
+             \_l_siunitx_negative_color_tl
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-
-%\begin{macro}{\newunit}
-%\begin{macro}{\renewunit}
-%\begin{macro}{\provideunit}
-%\doarg{keyval options}
-%\darg{unit}
-%\darg{symbol}
-% The \cs{newunit} and \cs{renewunit} macros create the new unit
-% macros. To allow a mechanism for checking an existing definition,
-% these macros simply carry out the appropriate tests, before handing
-% off to the internal macro.  \cs{@ifdefinable} is not used here as a
-% customised error is desirable. Other than that, the code here gives
-% very similar results to \cs{newcommand} and \cs{renewcommand}.
-% Finally, \cs{provideunit} adds the unit definition only if it does
-% not already exist.
-%    \begin{macrocode}
-\newcommand*{\newunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defunit[#1]{#2}{#3}}
-    {\si@log@err{Unit \string#2 already defined!}\@eha}}
-\newcommand*{\renewunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Unit \string#2 undefined}\@ehc
-     \si@unt@defunit[#1]{#2}{#3}}
-    {\si@log@inf{Redefining unit \string#2}%
-     \si@unt@defunit[#1]{#2}{#3}}}
-\newcommand*{\provideunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defunit[#1]{#2}{#3}}
-    {}}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_complex:}
+%\begin{macro}[aux]{\_siunitx_number_format_complex_aux:n}
+% The real and complex parts of each number are reassembled, with 
+% brackets if needed.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_complex: {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { complex-root } 
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_out_prop { complex }
+        {
+          \_siunitx_number_format_brackets:n { complex }
+          \_siunitx_number_format_complex_aux:n { complex }
+          \_siunitx_number_format_complex_aux:n { complex-result }
+          \prop_if_in:NnT \_l_siunitx_number_out_prop 
+            { complex-uncertainty }
+            { 
+              \_siunitx_number_format_complex_aux:n 
+                { complex-uncertainty } 
+            }  
+        }
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl
+            { 
+              \exp_not:N \_siunitx_ensuremath:n 
+                { \exp_not:V \_l_siunitx_output_complex_tl } 
+            }
+          \prop_put:NnV \_l_siunitx_number_out_prop { complex }
+            \_l_siunitx_tmpa_tl
+        }
+        \_siunitx_number_format_join_complex:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_complex_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \bool_if:NTF \_l_siunitx_complex_after_bool
+    {
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+        \_l_siunitx_output_complex_tl
+    }
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+        \_l_siunitx_output_complex_tl
+    }
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_copy:n}
+%\begin{macro}{\_siunitx_number_format_copy:nn}
+% Just copy across.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_copy:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop  {#1} \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_copy:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#2} \_l_siunitx_tmpa_tl
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\newprefix}
-%\begin{macro}{\renewprefix}
-%\begin{macro}{\provideprefix}
-%\doarg{\texttt{binary}}
-%\darg{multiple}
-%\darg{powers-ten}
-%\darg{symbol}
-% The multiples of units are defined here; very similar code is used
-% to the \cs{newunit}, \etc, macros.  The multiple prefixes cannot
-% take an optional argument, and must represent some power.  Hence
-% the arguments required are different.
-%    \begin{macrocode}
-\newcommand*{\newprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {\si@log@err{Prefix \string#2 already defined!}\@eha}}
-\newcommand*{\renewprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Prefix \string#2 undefined}\@ehc
-     \si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {\si@log@inf{Redefining prefix \string#2}%
-     \si@unt@defprefix[#1]{#2}{#3}{#4}}}
-\newcommand*{\provideprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {}}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_final:}
+% For numbers which do not contain an exponent, the mantissa result is
+% simply copied to the final output position. On the other hand, for
+% exponents there are further checks, which are handed off to dedicated
+% functions. There is also a check for complex numbers with no real
+% part, which needs to be \enquote{copied} to the standard result 
+% slot.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final: {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { complex }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { mantissa-result }
+        { 
+          \_siunitx_number_format_copy:nn { complex } 
+            { mantissa-result } 
+        }
+    }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { exponent }
+    {
+      \_siunitx_number_format_final_exponent:
+      \prop_if_in:NnTF \_l_siunitx_number_out_prop { mantissa-result } 
+        { \_siunitx_number_format_final_combined: }
+        { \_siunitx_number_format_final_exponent_only: }
+    }
+    { \_siunitx_number_format_copy:nn { mantissa-result } { result } }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-bracket } 
+    {
+      \prop_put:Nnn \_l_siunitx_number_out_prop { result-bracket } 
+        { true }
+      \prop_del:Nn \_l_siunitx_number_out_prop { mantissa-bracket } 
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_number_format_final_combined:}
+% When there is both a mantissa and an exponent, the mantissa is
+% combined with the product sign before adding the exponent part on.
+% The combined result is then stored. The marker
+% \texttt{result-bracket-exponent} indicates that the number needs
+% brackets due to the exponent part, but not in other cases.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final_combined: {
+  \_siunitx_number_format_brackets:n { mantissa }
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-result } 
+    \_l_siunitx_tmpa_tl
+  \tl_set_eq:NN \_l_siunitx_tmpb_tl \_l_siunitx_exponent_product_tl
+  \bool_if:NT \_l_siunitx_tight_bool 
+    {  
+      \tl_set:Nx \_l_siunitx_tmpb_tl 
+        { { \exp_not:V \_l_siunitx_tmpb_tl } }
+    }
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpb_tl
+  \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result } 
+    \_l_siunitx_tmpb_tl
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop { result } 
+    \_l_siunitx_tmpa_tl
+  \prop_put:Nnn \_l_siunitx_number_out_prop 
+    { result-bracket-exponent } { true }
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_number_format_final_exponent:}
+% When there is an exponent, the base always needs to be added to the
+% front of the number itself. The number must be superscripted, of 
+% course.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final_exponent: {
+  \prop_get:NnN \_l_siunitx_number_out_prop { exponent } 
+    \_l_siunitx_tmpa_tl
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+   { ^ { \exp_not:V \_l_siunitx_tmpa_tl } }
+  \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_exponent_base_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop { exponent-result } 
+    \_l_siunitx_tmpa_tl
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\newpower}
-%\begin{macro}{\renewpower}
-%\begin{macro}{\providepower}
-%\doarg{\texttt{post}}
-%\darg{number}
-%\darg{power}
-% Here power multiples for units are set up.  As with units and
-% multiples, a layered approach is used to keep things easy to
-% maintain.
-%    \begin{macrocode}
-\newcommand*{\newpower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defpower[#1]{#2}{#3}}
-    {\si@log@err{Power \string#2 already defined!}\@eha}}
-\newcommand*{\renewpower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Power \string#2 undefined}\@ehc
-     \si@unt@defpower[#1]{#2}{#3}}
-    {\si@log@inf{Redefining power \string#2}%
-     \si@unt@defpower[#1]{#2}{#3}}}
-\newcommand*{\providepower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defpower[#1]{#2}{#3}}
-    {}}
+%\begin{macro}{\_siunitx_number_format_final_exponent_only:}
+% When there is only an exponent, a check must be made for a 
+% sign in the mantissa part. If there is one, it is copied across.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_format_final_exponent_only: {
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl  
+    { 
+      \bool_if:NT \_l_siunitx_tight_bool 
+        {  
+          \tl_set:Nx \_l_siunitx_tmpa_tl 
+            { { \exp_not:V \_l_siunitx_tmpa_tl } }
+        }
+      \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpb_tl
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl 
+        \_l_siunitx_tmpa_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpb_tl
+    }
+  \_siunitx_number_format_copy:nn { exponent-result } { result }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_group:n}
+%\begin{macro}[aux]{\_siunitx_number_format_group_aux:nn}
+% Grouping digits only happens if there are no symbols in the input, and
+% of course if grouping has been requested.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group:n #1 {
+  \_siunitx_number_format_group_aux:nn {#1} { integer }
+  \_siunitx_number_format_group_aux:nn {#1} { decimal }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { #1 -integer } 
+    { \_siunitx_number_format_copy:nn { #1 -integer } {#1} }
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal-marker } 
+    \_l_siunitx_tmpb_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpb_tl  
+    {
+      \bool_if:NTF \_l_siunitx_output_decimal_copy_bool
+        { \tl_set:Nx \_l_siunitx_tmpb_tl { { \_l_siunitx_tmpb_tl } } }
+        {
+          \tl_set_eq:NN \_l_siunitx_tmpb_tl 
+            \_l_siunitx_output_decimal_tl
+        }
+      \tl_set:Nx \_l_siunitx_tmpb_tl 
+        { 
+          \exp_not:N \_siunitx_ensuremath:n 
+            { \exp_not:V \_l_siunitx_tmpb_tl } 
+        }
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl 
+      \prop_put:NnV \_l_siunitx_number_out_prop { #1 -decimal-marker }
+        \_l_siunitx_tmpb_tl
+      \prop_get:NnN \_l_siunitx_number_out_prop { #1 -decimal } 
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NT \_l_siunitx_tmpb_tl   
+        { \tl_clear:N \_l_siunitx_tmpb_tl }
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_aux:nn #1#2 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 - #2 } 
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { symbolic } 
+        { \_siunitx_number_format_copy:n { #1 - #2 } }
+        {
+          \bool_if:cTF { _l_siunitx_group_ #2 _bool } 
+            { \_siunitx_number_format_group_four:nn {#1} {#2} }
+            { \_siunitx_number_format_copy:n { #1 - #2 } }
+        } 
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\newqualifier}
-%\changes{v1.1}{2008/09/04}{New user macro}
-%\begin{macro}{\renewqualifier}
-%\changes{v1.1}{2008/09/04}{New user macro}
-%\begin{macro}{\providequalifier}
-%\changes{v1.1}{2008/09/04}{New user macro}
-%\darg{qualifier}
-%\darg{symbol}
-% Creating unit qualifiers is much the same method.
-%    \begin{macrocode}
-\newcommand*{\newqualifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@unt@defqual{#1}{#2}}
-    {\si@log@err{Qualifier \string#1 already defined!}\@eha}}
-\newcommand*{\renewqualifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@log@err{Qualifier \string#1 undefined}\@ehc
-     \si@unt@defqual{#1}{#2}}
-    {\si@unt@defqual{#1}{#2}}}
-\newcommand*{\providequalifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@unt@defqual{#1}{#2}}
-    {}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@unt@num}
-% A flag is needed to tell the processor whether there is a number,
-% to get the correct spacing.
-%    \begin{macrocode}
-\newif\ifsi@unt@num
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@unitarg}
-% A storage macro for the argument of the unit macro.
-%    \begin{macrocode}
-\newcommand*{\si@unt@unitarg}{}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@SI}
-%\changes{v1.2e}{2009/02/04}{Fixed issue with mode detection and units}
-%\begin{macro}{\si@unt@SIopts}
-%\doarg{keyval options}
-%\darg{unit}
-%\doarg{preunit}
-%\darg{unit}
-% The internal processing starts with \cs{si@SI}, which processes the
-% second optional argument to \cs{SI} (which is empty for \cs{si}).
-% Everything is set up in a group, and processing begins by handling
-% the options.
-%    \begin{macrocode}
-\newcommand*{\si@unt@SIopts}{}
-\def\si@SI[#1]#2[#3]#4{%
-  \begingroup
-    \let\fg\SIfg
-    \sisetup{#1}%
-    \renewcommand*{\si@unt@SIopts}{#1}%
-    \si@fam@mode
-%    \end{macrocode}
-%\end{macro}
-% The prefix unit is handled before any processing of the number; the
-% flags are set to get spacing correct.
-%    \begin{macrocode}
-    \si@unt@numfalse
-    \si@xspacefalse
-    \si@ifnotmtarg{#3}
-      {\si@log@debug{Prefix unit found}%
-       \si@unt@printunit{#3}}%
-%    \end{macrocode}
-% The numerical argument may be empty, in which case no extra space
-% should be produced.
-%    \begin{macrocode}
-    \si@ifnotmtarg{#4}
-      {\renewcommand*{\si@unt@unitarg}{#4}}%
-    \si@ifnotmtarg{#2}
-      {\si@log@debug{Number found in \string\SI\space
-         argument}%
-       \ifsi@repeatunits\else
-         \ifsi@trapambigerr
-           \expandafter\expandafter\expandafter
-             \si@num@ambigerrtrue
-         \fi
-       \fi
-       \num{#2}%
-       \si@unt@numtrue}%
-%    \end{macrocode}
-% If there is a unit, a check is needed in case the units need to
-% have a power added.
-%    \begin{macrocode}
-    \si@ifnotmtarg{#4}
-      {\si@ifmtarg{#2}
-         {\si@unt@printunit{#4}}
-         {\si@tempcnta\z@\relax
-         \ifsi@addunitpower
-           \si@unt@countx{#2}%
-         \fi
-          \ifnum\si@tempcnta>\z@\relax
-            \advance\si@tempcnta\@ne\relax
-            \edef\si@tempa{\noexpand\tothe{\si@tempcnta}}%
-            \renewcommand*{\si@tempb}{#4}%
-            \expandafter\expandafter\expandafter
-            \si@unt@printunit\expandafter\expandafter
-            \expandafter{%
-              \expandafter\si@tempb\si@tempa}%
-          \else
-            \si@unt@printunit{#4}%
-          \fi}}%
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@countx}
-% A short macro to count up any multiplication in numerical input.
-%    \begin{macrocode}
-\newcommand*{\si@unt@countx}[1]{%
-  \si@tempcnta\z@\relax
-  \expandafter\si@unt@cntx#1\@empty\@empty}
-\def\si@unt@cntx#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numprod}
-    {\advance\si@tempcnta\@ne\relax}
-    {}%
-  \ifx\@empty#2\@empty\else
-    \si@unt@cntx#2\@empty\@empty
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@ifliteral}
-%\begin{macro}{\ifsi@unt@littest}
-%\darg{unit}
-% The next stage of the processor is to determine whether or not the
-% argument of the unit macro is processable.  For literal arguments,
-% this is not the case, and the argument is typeset ``as is''.  On
-% the other hand, any units, \etc., declared by the package will work
-% with the processor, and so need to be executed before typesetting
-% the result.
-%    \begin{macrocode}
-\newif\ifsi@unt@littest
-\newcommand*{\si@unt@ifliteral}[1]{%
-  \begingroup
-    \si@unt@littesttrue
-%    \end{macrocode}
-% The test relies on any non-processable test having some width;
-% hopefully, this should be the case.
-%    \begin{macrocode}
-    \setbox\si@tempboxa=\hbox{\si@unt@out{#1}}%
-    \ifdim\wd\si@tempboxa>\z@\relax
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\ifsi@unt@litout}
-%\begin{macro}{\si@unt@printunit}
-%\darg{unit}
-% The printing macro uses the above test to determine how to act.  It
-% then carries out the appropriate action: either typesetting or
-% executing.  A flag is also provided so that any macro units inside
-% a partially-literal argument will work (this is also needed to
-% emulate \unitsdef).
-%    \begin{macrocode}
-\newif\ifsi@unt@litout
-\newcommand*{\si@unt@printunit}[1]{%
-  \si@unt@ifliteral{#1}
-%    \end{macrocode}
-% The unit includes one or more literal items; typeset using the
-% unit typesetting macro.
-%    \begin{macrocode}
-    {\ifsi@allowlitunits
-        \expandafter\si@unt@litprint
-     \else
-        \expandafter\si@unt@nolitprint
-     \fi
-     {#1}}
-%    \end{macrocode}
-% For processable output, the argument is executed; the macros are
-% all designed for this.
-%    \begin{macrocode}
-    {\si@log@debug{Macro unit found:\MessageBreak
-       processing to format output}%
-     \si@unt@init
-     \advance\si@unt@depthcnt\@ne\relax
-     #1%
-     \si@unt@final}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@litprint}
-%\begin{macro}{\si@unt@nolitprint}
-% A couple of related macros to cope with literal printing (or not).
-%    \begin{macrocode}
-\newcommand*{\si@unt@litprint}[1]{%
-  \si@log@debug{%
-    Literal items found in unit argument:\MessageBreak outputting 
-    without further processing}%
-  \si@unt@litouttrue
-  \si@unt@addvaluesep
-  \si@unt@out{#1}%
-}
-\newcommand*{\si@unt@nolitprint}[1]{%
-  \si@log@err{Literal units disabled}{%
-    You can the literal input `#1' for a unit\MessageBreak
-    but the allowliteralunits option is off.
-  }
+%\begin{macro}{\_siunitx_number_format_group_four:nn}
+%\begin{macro}[aux]{\_siunitx_number_format_group_four_aux:NNNNNNw}
+%\begin{macro}[aux]{\_siunitx_number_format_group_four_aux:nn}
+% The idea here is that grouping is only needed for items with at 
+% least four tokens in them, and perhaps five if the grouping of 
+% four-digit numbers is turned off.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_four:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 - #2 } 
+    \_l_siunitx_tmpa_tl
+  \bool_if:NTF \_l_siunitx_group_four_bool 
+    { \_siunitx_number_format_group_four_aux:nn {#1} {#2} }
+    {
+      \exp_after:wN \_siunitx_number_format_group_four_aux:NNNNNNw
+        \_l_siunitx_tmpa_tl \q_no_value \q_no_value \q_no_value
+        \q_no_value \q_no_value \q_nil
+        { \_siunitx_number_format_copy:n {#1 - #2} }
+        { \_siunitx_number_format_group_four_aux:nn {#1} {#2} }       
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_four_aux:NNNNNNw 
+  #1#2#3#4#5#6 \q_nil {
+  \quark_if_no_value:NTF #5
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_four_aux:nn 
+  #1#2 {
+  \tl_clear:N \_l_siunitx_tmpb_tl
+  \use:c { _siunitx_number_format_group_ #2 : }
+  \prop_put:NnV \_l_siunitx_number_out_prop { #1 - #2 } 
+    \_l_siunitx_tmpb_tl
 }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@unt@addvaluesep}
-%\begin{macro}{\si@unt@addvalsep}
-%\begin{macro}{\si@unt@litvalsep}
-%\begin{macro}{\si@unt@stackvalsep}
-% To ensure no problems pop up with expansion, adding the value--unit
-% space is handled by a macro.
-%    \begin{macrocode}
-\newcommand*{\si@unt@addvaluesep}{%
-  \ifsi@unt@num
-    \expandafter\si@unt@addvalsep
-  \fi}
-\newcommand*{\si@unt@addvalsep}{%
-  \ifsi@unt@litout
-    \expandafter\si@unt@litvalsep
-  \else
-    \expandafter\si@unt@stackvalsep
-  \fi}
-\newcommand*{\si@unt@stackvalsep}{%
-  \protected@edef\si@unt@spstack{\si@valuesep}}
-\newcommand*{\si@unt@litvalsep}{%
-  \nobreak\ensuremath{\si@valuesep}\nobreak}
-%    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@spstack}
-%\begin{macro}{\si@unt@stacka}
-%\begin{macro}{\si@unt@stackb}
-%\begin{macro}{\si@unt@unitcnta}
-%\begin{macro}{\si@unt@unitcntb}
-%\begin{macro}{\si@unt@depthcnt}
-%\begin{macro}{\ifsi@unt@first}
-%\begin{macro}{\ifsi@unt@first}
-%\begin{macro}{\si@unt@init}
-% The initialisation macro sets up the various switches, and clears
-% the storage areas for the formatted output.  There are two stacks,
-% as when typesetting as fractions, the two parts of the number have
-% to be stored separately.  The depth counter is used to tell when
-% recursion ends in the processor.  The ``first'' switch is needed as
-% the depth counter will not be at one for items processed by
-% \cs{SI}.
-%    \begin{macrocode}
-\newcommand*{\si@unt@spstack}{}
-\newcommand*{\si@unt@stacka}{}
-\newcommand*{\si@unt@stackb}{}
-\newcount\si@unt@unitcnta
-\newcount\si@unt@unitcntb
-\newcount\si@unt@depthcnt
-\newif\ifsi@unt@first
-\si@unt@depthcnt\m@ne\relax
-\newcommand*{\si@unt@init}{%
-  \begingroup
-    \si@unt@litoutfalse
-    \si@unt@litprefixfalse
-    \si@unt@firsttrue
-    \si@unt@perfalse
-    \si@unt@perseenfalse
-    \si@unt@prepowerfalse
-    \si@unt@depthcnt\z@\relax
-    \si@unt@powerdim\z@\relax
-    \si@unt@unitcnta\z@\relax
-    \si@unt@unitcntb\z@\relax
-    \si@unt@prefixcnt\z@\relax
-    \renewcommand*{\si@unt@spstack}{}%
-    \renewcommand*{\si@unt@stacka}{}%
-    \renewcommand*{\si@unt@stackb}{}%
-    \renewcommand*{\si@unt@spacestacka}{}%
-    \renewcommand*{\si@unt@spacestackb}{}%
-    \renewcommand*{\si@unt@lastadda}{space}%
-    \renewcommand*{\si@unt@lastaddb}{space}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@final}
-% The finalisation macro finishes off the output and resets the flags.
-%    \begin{macrocode}
-\newcommand*{\si@unt@final}{%
-    \si@unt@third
-    \si@unt@stackout
-  \endgroup
-  \ifsi@xspace
-    \expandafter\expandafter\expandafter\xspace
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@defunit}
-%\doarg{keyval options}
-%\darg{unit}
-%\darg{symbol}
-% The internal macro for defining a unit does not check for
-% redefinition; that is done by the user macros.
-%    \begin{macrocode}
-\newcommand*{\si@unt@defunit}[3][]{%
-  \si@log@debug{Declaring unit \string#2 with \MessageBreak
-    meaning \string#3}%
-%    \end{macrocode}
-% The optional argument needs to be saved. The macro name is reversed
-% so that life is easier with the expansions here.
-%    \begin{macrocode}
-  \si@ifnotmtarg{#1}
-    {\expandafter\@namedef\expandafter{%
-      \expandafter\@gobble\string#2@opt@unt@si}{#1}}%
-%    \end{macrocode}
-% The unit macro itself is now defined.  The definition simply
-% selects the correct path for the rest of the processing to go down.
-%    \begin{macrocode}
-  \protected\def#2{%
-    \ifsi@allowoptarg
-      \expandafter\si@unt@withopt
-    \else
-      \expandafter\si@unt@noopt
-    \fi
-    {#2}{#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@withopt}
-%\begin{macro}{\si@unt@noopt}
-%\darg{unit}
-%\darg{symbol}
-% To allow the correct expansion, the potential optional argument to
-% a unit macro has to come last.  So \cs{@ifnextchar} is needed to
-% detect it and pass data through.  To keep variation down, when the
-% argument is not allowed, the empty |[]| is supplied.
-%    \begin{macrocode}
-\newcommand*{\si@unt@withopt}[2]{%
-  \@ifnextchar[%]
-    {\si@unt@opt{#1}{#2}}
-    {\si@unt@opt{#1}{#2}[]}}
-\newcommand*{\si@unt@noopt}[2]{\si@unt@opt{#1}{#2}[]}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@opt}
-%\darg{unit}
-%\darg{symbol}
-%\doarg{number}
-% The optional argument to the unit macro (if present) is converted
-% to a normal one for ease.  The correct route for processing is then
-% picked.
-%    \begin{macrocode}
-\def\si@unt@opt#1#2[#3]{%
-  \ifsi@unt@littest
-    \expandafter\si@gobblethree
-  \else
-%    \end{macrocode}
-% For literal output, the second argument is all that is needed.
-%    \begin{macrocode}
-    \ifsi@unt@litout
-      \expandafter\expandafter\expandafter\@gobbletwo
-    \else
-      \expandafter\expandafter\expandafter\si@unt@unit
-    \fi
-  \fi
-  {#3}{#1}{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@gobblethree}
-% \LaTeX\ does not have a \cs{@gobblethree} macro, but one is needed.
-%    \begin{macrocode}
-\long\def\si@gobblethree #1#2#3{}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@defprefix}
-%\begin{macro}{\ifsi@unt@litprefix}
-%\doarg{\texttt{binary}}
-%\darg{multiple}
-%\darg{powers-ten}
-%\darg{symbol}
-% As with units, multiples are defined by an internal macro.
-%    \begin{macrocode}
-\newif\ifsi@unt@litprefix
-\si@unt@litprefixtrue
-\newcommand*{\si@unt@defprefix}[4][]{%
-  \si@log@debug{Declaring multiple \string#1 with\MessageBreak
-    meaning \string#4}%
-%    \end{macrocode}
-% The optional argument is saved, using \cs{def} as no check is made
-% on an existing definition of the storage macro.
-%    \begin{macrocode}
-  \expandafter\expandafter\expandafter\def\expandafter
-    \csname\expandafter\@gobble\string#2@opt@si\endcsname{#1}%
-  \protected\def#2{%
-    \ifsi@unt@littest
-      \expandafter\si@gobblethree
-    \else
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\@gobbletwo
-      \else
-        \ifsi@unt@litprefix
-          \expandafter\expandafter\expandafter\expandafter
-            \expandafter\expandafter\expandafter\@gobbletwo
-        \else
-          \expandafter\expandafter\expandafter\expandafter
-            \expandafter\expandafter\expandafter\si@unt@prefix
-        \fi
-      \fi
-    \fi
-    {#2}{#3}{#4}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@defpower}
-%\doarg{\texttt{post}}
-%\darg{number}
-%\darg{power}
-% The definition of powers is complicated by the need to handle both
-% those given before units (such as \cs{cubic}) and those given after
-% (\eg \cs{cubed}).  This means that an optional argument is needed.
-%    \begin{macrocode}
-\newcommand*{\si@unt@defpower}[3][]{%
-  \si@log@debug{Declaring power \string#2 with\MessageBreak
-    meaning \string#3}%
-%    \end{macrocode}
-% Once again the optional argument is saved.
-%    \begin{macrocode}
-  \expandafter\expandafter\expandafter\def\expandafter
-    \csname\expandafter\@gobble\string#2@opt@si\endcsname{#1}%
-  \protected\def#2{%
-    \ifsi@unt@littest
-      \expandafter\@gobbletwo
-    \else
-%    \end{macrocode}
-% The literal output here does not need to gobble anything.
-%    \begin{macrocode}
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\si@unt@litpower
-      \else
-        \expandafter\expandafter\expandafter\si@unt@power
-      \fi
-    \fi
-    {#2}{#3}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@defqual}
-%\darg{qualifier}
-%\darg{symbol}
-% Qualifiers are defined in a similar manner.
-%    \begin{macrocode}
-\newcommand*{\si@unt@defqual}[2]{%
-  \si@log@debug{Declaring qualifier \string#1 with\MessageBreak
-    meaning \string#2}%
-  \protected\def#1{%
-    \ifsi@unt@littest
-      \expandafter\@gobble
-    \else
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\si@unt@litqual
-      \else
-        \expandafter\expandafter\expandafter\si@unt@qual
-      \fi
-    \fi
-    {#2}}}
-%    \end{macrocode}
-%\end{macro}
-%
-%\begin{macro}{\si@unt@unithook}
-%\begin{macro}{\si@unt@unit}
-%\darg{number}
-%\darg{unit}
-%\darg{symbol}
-% The macro for units is actually a processor, rather than
-% typesetting anything, which is handled elsewhere.  The first
-% argument to the macro is optional, but does not have square
-% brackets to keep things simple with gobbling.
-%    \begin{macrocode}
-\newcommand*{\si@unt@unithook}{}
-\newcommand*{\si@unt@unit}[3]{%
-%    \end{macrocode}
-% When the count is minus one at the start of the processor, then the
-% unit is begin used on its own: initialisation occurs.
-%    \begin{macrocode}
-  \ifnum\si@unt@depthcnt=\m@ne\relax
-    \expandafter\si@unt@init
-  \fi
-  \advance\si@unt@depthcnt\@ne\relax
-  \si@log@debug{Unit processing: level \the\si@unt@depthcnt,
-    \MessageBreak unit \string#2}%
-  \si@unt@firstorsecond{#1}{#2}%
-%    \end{macrocode}
-% The core of the \cs{si@unt@unit} macro is testing if the symbol for
-% the unit is a literal value or another macro.  Depending on the
-% result, the symbol is either used as a literal or executed.
-%    \begin{macrocode}
-  \si@unt@ifliteral{#3}
-    {\si@unt@addtostack{unit}{#3}%
-     \ifsi@unt@prepower
-       \expandafter\si@unt@stkpower
-     \fi}
-    {#3}%
-%    \end{macrocode}
-% The counter is now stepped down, before checking if this is
-% the end of a compound unit.
-%    \begin{macrocode}
-  \advance\si@unt@depthcnt\m@ne\relax
-  \ifnum\si@unt@depthcnt=\z@\relax
-    \expandafter\si@unt@final
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@firstorsecond}
-%\darg{number}
-%\darg{unit-macro}
-% At this stage, the flag will be set for the first item to be
-% processed whichever route the unit has been called by.
-%    \begin{macrocode}
-\newcommand*{\si@unt@firstorsecond}[2]{%
-  \ifsi@unt@first
-    \expandafter\si@unt@first
-  \else
-    \expandafter\si@unt@second
-  \fi
-  {#1}{#2}}%
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@first}
-%\darg{number}
-%\darg{unit-macro}
-% For the first unit in the input, some extra tasks are needed.
-% First, the optional argument for the unit macro needs to be
-% tested.
-%    \begin{macrocode}
-\newcommand*{\si@unt@first}[2]{%
-  \si@ifnotmtarg{#1}
-    {\num{#1}%
-     \si@unt@numtrue}%
-  \si@unt@unithook
-%    \end{macrocode}
-% To avoid filling up the macro list with useless values, the \eTeX\
-% primitive \cs{ifcsname} is employed here (it also avoids complex
-% expansion issues).  If some options exist, they are set.
-%    \begin{macrocode}
-  \ifcsname\expandafter\@gobble\string#2@opt@unt@si\endcsname
-    \expandafter\si@unt@setopts
-  \else
-    \expandafter\@gobble
-  \fi
-  {#2}%
-  \si@unt@addvaluesep
-  \si@unt@firstfalse}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@setopts}
-%\begin{macro}{\si@unt@setSIopts}
-%\darg{unit}
-% A rather long set of \cs{expandafter} commands to get the options
-% to set safely.
-%    \begin{macrocode}
-\newcommand*{\si@unt@setopts}[1]{%
-  \expandafter\expandafter\expandafter\expandafter\expandafter
-    \expandafter\expandafter\si@temptoks\expandafter
-    \expandafter\expandafter\expandafter\expandafter
-    \expandafter\expandafter{\expandafter%
-      \csname\expandafter\@gobble\string#1@opt@unt@si%
-      \endcsname}%
-  \expandafter\sisetup\expandafter{\the\si@temptoks}%
-  \si@log@debug{Applying options `\the\si@temptoks'
-    for\MessageBreak unit \string#1}%
-%    \end{macrocode}
-% The user options are reloaded, if defined, to ensure that they
-% still work as expected.
-%    \begin{macrocode}
-  \@ifundefined{si@unt@SIopts}{}
-    {\ifx\@empty\si@unt@SIopts\@empty\else
-       \expandafter\expandafter\si@unt@setSIopts
-     \fi}}
-\newcommand*{\si@unt@setSIopts}{%
-  \expandafter\si@temptoks\expandafter{\si@unt@SIopts}%
-  \expandafter\sisetup\expandafter{\the\si@temptoks}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@second}
-%\begin{macro}{\si@unt@third}
-%\darg{number}
-%\darg{unit}
-% For everything apart from the first item to be processed, spacing
-% may need to be added to separated different units.  The macro is
-% divided into two, so that everything except the space can be added
-% in finalisation.
-%    \begin{macrocode}
-\newcommand*{\si@unt@second}[2]{%
-  \si@ifnotmtarg{#1}
-    {\si@log@warn{Optional argument to unit macro\MessageBreak
-       allowed only for outer unit}}%
-  \si@unt@third
-  \si@unt@addtostack{space}{\ensuremath{\si@unitsep}}}
-\newcommand*{\si@unt@third}{%
-  \ifsi@unt@prepower\else
-    \expandafter\si@unt@stkpower
-  \fi
-%    \end{macrocode}
-% A check is made to avoid adding $-1$ to prefixes.  If \opt{frac} is
-% active, then the |b| stack will be in use, otherwise it will be
-% |a|.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{prefix}%
-  \expandafter\ifx
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname\si@tempa
-  \else
-    \expandafter\si@unt@spacecheck
-  \fi
-  \ifsi@unt@per
-    \expandafter\si@unt@perseentrue
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@spacecheck}
-% A check to prevent adding $-1$ at the very beginning of the unit,
-% where there is a space on the stack.
-%    \begin{macrocode}
-\newcommand*{\si@unt@spacecheck}{%
-  \renewcommand*{\si@tempa}{space}%
-  \expandafter\ifx
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname\si@tempa
-  \else
-    \expandafter\si@unt@reciptest
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@prefix}
-%\darg{multiple}
-%\darg{power-ten}
-%\darg{symbol}
-% Actual output of the prefixes.
-%    \begin{macrocode}
-\newcommand*{\si@unt@prefix}[3]{%
-  \si@unt@firstorsecond{}{#1}%
-  \ifsi@prefixsymbolic
-    \expandafter\si@unt@addprefix
-  \else
-    \expandafter\si@unt@countprefix
-  \fi
-  {#1}{#2}{#3}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@addprefix}
-%\darg{gobbled}
-%\darg{gobbled}
-%\darg{symbol}
-% To add the prefix, a little translation is needed.
-%    \begin{macrocode}
-\newcommand*{\si@unt@addprefix}[3]{%
-  \si@unt@addtostack{prefix}{#3}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@prefixcnt}
-% A storage area is created.
-%    \begin{macrocode}
-\newcount\si@unt@prefixcnt
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@countprefix}
-%\begin{macro}{\si@unt@invprefix}
-%\darg{multiple}
-%\darg{powers-ten}
-%\darg{gobbled}
-% To count the prefix numeral, the symbol is thrown away.  First, a
-% check is made for binary units.
-%    \begin{macrocode}
-\newcommand*{\si@unt@countprefix}[3]{%
-  \renewcommand*{\si@tempa}{binary}%
-  \expandafter\expandafter\expandafter\ifx\expandafter
-    \csname\expandafter\@gobble\string#1@opt@si\endcsname
-    \si@tempa
-    \expandafter\sisetup
-  \else
-    \expandafter\@gobble
-  \fi
-  {prefixbase=two}%
-  \si@tempcnta#2\relax
-  \ifsi@unt@per
-    \expandafter\si@unt@invprefix
-  \fi
-  \advance\si@unt@prefixcnt\si@tempcnta\relax}
-\newcommand*{\si@unt@invprefix}{%
-  \si@tempcntb\si@tempcnta\relax
-  \si@tempcnta -\si@tempcntb\relax}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@litpower}
-%\darg{gobbled}
-%\darg{number}
-% For literal power output, the number can't simply be dumped, so
-% a macro is needed.
-%    \begin{macrocode}
-\newcommand*{\si@unt@litpower}[2]{\textsuperscript{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@unt@prepower}
-% If a power is seen before a unit, tracking is needed.
-%    \begin{macrocode}
-\newif\ifsi@unt@prepower
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@power}
-%\darg{power}
-%\darg{number}
-% The handling of powers starts by ensuring that ``pre'' powers
-% follow \cs{per} cleanly.  Then a check is needed for inversion.
-%    \begin{macrocode}
-\newcommand*{\si@unt@power}[2]{%
-  \renewcommand*{\si@tempa}{post}%
-  \expandafter\expandafter\expandafter\ifx\expandafter
-    \csname\expandafter\@gobble\string#1@opt@si\endcsname
-    \si@tempa
-    \expandafter\@gobbletwo
-  \else
-    \expandafter\si@unt@firstorsecond
-  \fi
-  {}{\power}%
-  \si@unt@powerdim #2 pt\relax
-  \ifsi@frac\else
-    \ifsi@unt@per
-      \expandafter\expandafter\expandafter\si@unt@invpower
-    \fi
-  \fi
-  \renewcommand*{\si@tempa}{post}%
-  \si@unt@prepowertrue
-  \expandafter\expandafter\expandafter\ifx\expandafter
-    \csname\expandafter\@gobble\string#1@opt@si\endcsname
-    \si@tempa
-    \expandafter\si@unt@stackpower
-  \else
-    \si@log@debug{Power \strip@pt\si@unt@powerdim\space saved
-      to be added after\MessageBreak next unit}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@powerdim}
-% To do sign-inversion on the power, a dimension is used (this allows
-% non-integer values to be handled).
-%    \begin{macrocode}
-\newdimen\si@unt@powerdim
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@stackpower}
-%\begin{macro}{\si@unt@stkpower}
-%\begin{macro}{\si@unt@stkpwr}
-%\begin{macro}{\si@unt@skpwr}
-% Adding powers to the stack should also clear the power list.  If
-% the number is already zero, then  of course nothing happens.
-%    \begin{macrocode}
-\newcommand*{\si@unt@stackpower}{%
-  \si@unt@prepowerfalse
-%    \end{macrocode}
-% A trap is used for $-1$ added to the denominator of a fraction.
-%    \begin{macrocode}
-  \si@unt@stkpower
-  \ifsi@stickyper\else
-    \si@unt@perfalse
-    \si@unt@perseenfalse
-  \fi}
-%    \end{macrocode}
-% The \cs{si@unt@stkpower} macro needs to be called from a few
-% places, so is spun out from the above.
-%    \begin{macrocode}
-\newcommand*{\si@unt@stkpower}{%
-  \ifdim\si@unt@powerdim=\m@ne pt\relax
-    \ifsi@frac\else
-      \expandafter\expandafter\expandafter\si@unt@stkpwr
-    \fi
-  \else
-    \expandafter\si@unt@stkpwr
-  \fi}
-%    \end{macrocode}
-%\changes{v1.1}{2008/09/04}{Altered to account for qualifiers}
-% Finally, the actual adding (set up to avoid problems with the
-% \cs{if} above).
-%    \begin{macrocode}
-\newcommand*{\si@unt@stkpwr}{%
-  \ifdim\si@unt@powerdim=\z@\relax\else
-    \renewcommand*{\si@tempa}{unit}%
-    \expandafter\ifx
-      \csname si@unt@lastadd\si@unt@checkstack\endcsname
-      \si@tempa
-      \si@unt@skpwr
-    \else
-      \renewcommand*{\si@tempa}{qual}%
-      \expandafter\ifx
-        \csname si@unt@lastadd\si@unt@checkstack\endcsname
-        \si@tempa
-        \si@unt@skpwrqual
-      \fi
-    \fi
-  \fi
-  \si@unt@powerdim\z@\relax}
-\newcommand*{\si@unt@skpwr}{%
-  \si@log@debug{Adding power
-    \strip@pt\si@unt@powerdim\space to output stack}%
-  \si@unt@addtostack{power}{^{\num[fixdp=false]{%
-    \strip@pt\si@unt@powerdim}}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@invpower}
-% A macro to change the sign of the current power.
-%    \begin{macrocode}
-\newcommand*{\si@unt@invpower}{%
-  \si@tempdima\si@unt@powerdim\relax
-  \si@unt@powerdim -\si@tempdima\relax
-%    \end{macrocode}
-% The power might end up as ``1'', which is not wanted.  So it is
-% chucked away.
-%    \begin{macrocode}
-  \ifdim\si@unt@powerdim=\p@\relax
-    \si@unt@powerdim\z@\relax
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@litqual}
-%    \begin{macrocode}
-\newcommand*{\si@unt@litqual}[1]{(#1)}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@qual}
+%\begin{macro}{\_siunitx_number_format_group_decimal:}
+%\begin{macro}[aux]{\_siunitx_number_format_group_decimal_aux:}
+% Using the \enquote{keep everything on the stack} approach, relatively
+% simple recursion is needed. This trick is taken more or less directly
+% from \pkg{numprint}.
 %    \begin{macrocode}
-\newcommand*{\si@unt@qual}[1]{%
-  \ifsi@unt@first
-    \si@log@err{Qualifier before units}
-      {A unit qualifier can only be given after\MessageBreak
-       one or more units.  You tried to open a unit
-       with\MessageBreak \string#1}%
-  \fi
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_decimal: {
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl 
+    { 
+      \exp_after:wN \_siunitx_number_format_group_decimal_aux:NNNN 
+        \_l_siunitx_tmpa_tl { } { } { }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_decimal_aux:NNNN 
+  #1#2#3#4 {
+  \tl_if_empty:nTF {#2} 
+    { \tl_put_right:Nn \_l_siunitx_tmpb_tl {#1} }
+    {
+      \tl_if_empty:nTF {#3} 
+        { \tl_put_right:Nn \_l_siunitx_tmpb_tl { #1 #2 } }
+        {
+          \tl_put_right:Nn \_l_siunitx_tmpb_tl { #1 #2 #3 }
+          \tl_if_empty:nF {#4} 
+            {
+              \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpb_tl 
+                \_l_siunitx_group_sep_tl
+              \_siunitx_number_format_group_decimal_aux:NNNN #4
+            }
+        }
+    }
+}
 %    \end{macrocode}
-% The space after the current unit is shuffled so it will come
-% after the qualifier.
+%\end{macro}
+%\end{macro}
+%\begin{macro}{\_siunitx_number_format_group_integer:}
+%\begin{macro}[aux]{\_siunitx_number_format_group_integer_setup:n}
+%\begin{macro}[aux]{\_siunitx_number_format_group_integer_setup:V}
+%\begin{macro}[aux]{\_siunitx_number_format_group_integer_setup_aux:NNNN}
+%\begin{macro}[aux]{\_siunitx_number_format_group_integer_aux:NNNN}
+% By keeping everything on the stack, recursion can occur quite 
+% efficiently here.
 %    \begin{macrocode}
-  \expandafter\let\expandafter\si@unt@spacestack
-    \csname si@unt@spacestack\si@unt@checkstack\endcsname
-  \expandafter\let\csname si@unt@spacestack\si@unt@checkstack
-    \endcsname\@empty
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_integer: {
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl 
+    { 
+      \_siunitx_number_format_group_integer_setup:V \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_integer_setup:n #1 {
+  \_siunitx_number_format_group_integer_setup_aux:NNNN 
+    { } #1 { } { } { }
+}
+\cs_generate_variant:Nn \_siunitx_number_format_group_integer_setup:n 
+  { V }
+\cs_set_protected:Npn 
+  \_siunitx_number_format_group_integer_setup_aux:NNNN #1#2#3#4 {
+  \tl_if_empty:nTF {#2} 
+    { \_siunitx_number_format_group_integer_aux:NNNN #1 \q_nil }
+    {
+      \tl_if_empty:nTF {#3} 
+        {
+          \_siunitx_number_format_group_integer_aux:NNNN { } { } #1#2 
+            \q_nil
+        }
+        {
+          \tl_if_empty:nTF {#4} 
+            {
+              \_siunitx_number_format_group_integer_aux:NNNN { } #1#2#3
+                \q_nil
+            }
+            {
+              \_siunitx_number_format_group_integer_setup_aux:NNNN 
+                {#1#2#3#4}
+            }
+        }
+    }  
+}
+\cs_set_protected:Npn 
+  \_siunitx_number_format_group_integer_aux:NNNN #1#2#3#4 {
+  \tl_put_right:Nn \_l_siunitx_tmpb_tl {#1#2#3}
+  \quark_if_nil:nF {#4} 
+    {
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpb_tl 
+        \_l_siunitx_group_sep_tl
+      \_siunitx_number_format_group_integer_aux:NNNN #4
+    }
+}
 %    \end{macrocode}
-%\begin{macro}{\si@unt@skpwrqual}
-% Some protection against trying to add two powers.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{power}%
-    \expandafter\ifx
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname\si@tempa
-    \let\si@unt@skpwrqual\relax
-  \else
-    \let\si@unt@skpwrqual\si@unt@skpwr
-  \fi
-  \si@unt@addtostack{qual}{_{#1}}%
-  \expandafter\let\csname si@unt@spacestack\si@unt@checkstack
-    \endcsname\si@unt@spacestack}
-%    \end{macrocode}
-%\end{macro}
 %\end{macro}
-%\begin{macro}{\ifsi@unt@per}
-%\begin{macro}{\ifsi@unt@perseen}
-%\begin{macro}{\per}
-%\begin{macro}{\si@per}
-%\begin{macro}{\si@unt@per}
-% The \cs{per} macro sets the correct flags; almost everything else
-% is done elsewhere.  There is always the case of two \cs{per}
-% instructions; so the flag is flipped rather than set arbitrarily.
-% The second flag is needed so that \cs{per} can give powers of $-1$
-% properly.
-%    \begin{macrocode}
-\newif\ifsi@unt@per
-\newif\ifsi@unt@perseen
-\si@newrobustcmd*{\si@per}{%
-  \ifsi@unt@littest\else
-    \ifsi@unt@litout
-      \expandafter\expandafter\expandafter /%
-    \else
-      \ifsi@unt@litprefix
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter /%
-      \else
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter\si@unt@per
-      \fi
-    \fi
-  \fi}
-\newcommand*{\si@unt@per}{%
-  \si@unt@firstorsecond{}{\per}%
-  \ifsi@unt@per
-    \ifsi@stickyper\else
-      \expandafter\expandafter\expandafter\si@unt@perfalse
-    \fi
-  \else
-    \expandafter\si@unt@pertrue
-  \fi}
-\let\per\si@per
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@reciptest}
-%\begin{macro}{\si@unt@recip}
-% A test is needed for adding $-1$ when needed. The second macro is
-% fired only if the power should be reciprocal.
-%    \begin{macrocode}
-\newcommand*{\si@unt@reciptest}{%
-  \ifsi@unt@per
-    \ifsi@unt@perseen
-      \expandafter\expandafter\expandafter\si@unt@recip
-    \fi
-  \fi}
-\newcommand*{\si@unt@recip}{%
-  \si@unt@powerdim\m@ne pt\relax
-  \si@unt@stackpower}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@lastadda}
-%\begin{macro}{\si@unt@lastaddb}
-% Items cannot be added directly to the stacks (except the spacing
-% stack, a) as the fractional handling may need to add the item to
-% either storage area. First, a track is kept of what has
-% been added at each stage.
-%    \begin{macrocode}
-\newcommand*{\si@unt@lastadda}{}
-\newcommand*{\si@unt@lastaddb}{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@addtostack}
-%\changes{v1.1b}{2008/10/12}{Added warning for multiple prefixes}
-%\darg{type}
-%\darg{token}
-% By indicating the type of data to be added to the stack, problems
-% can be avoided.
-%    \begin{macrocode}
-\newcommand*{\si@unt@addtostack}[2]{%
-  \renewcommand*{\si@tempa}{#1}%
-%    \end{macrocode}
-% Two consecutive items cannot be of the same type; there must be spaces
-% between units, units between prefixes, \etc.
-%    \begin{macrocode}
-  \expandafter\ifx
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname\si@tempa
-      \renewcommand*{\si@tempa}{prefix}%
-      \expandafter\ifx\csname si@unt@lastadd\si@unt@checkstack
-        \endcsname\si@tempa
-        \si@log@warn{Two prefixes found: only first printed}%
-      \fi
-    \expandafter\@gobbletwo
-  \else
-    \expandafter\si@unt@preplussp
-  \fi
-  {#1}{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@preplussp}
-%\darg{type}
-%\darg{stack}
-%\darg{token}
-%\darg{gobbled}
-% The space added after a prefix needs to be ignored.
-%    \begin{macrocode}
-\newcommand*{\si@unt@preplussp}[2]{%
-  \renewcommand*{\si@tempa}{prefix+space}%
-  \edef\si@tempb{%
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname+#1}%
-  \ifx\si@tempa\si@tempb
-    \expandafter\@gobbletwo
-  \else
-    \expandafter\si@unt@stack
-  \fi
-  {#1}{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@stack}
-%\darg{type}
-%\darg{token}
-% The macro for actually doing the stacking up.
-%    \begin{macrocode}
-\newcommand*{\si@unt@stack}[2]{%
-  \expandafter\renewcommand\expandafter*\expandafter{%
-    \csname si@unt@lastadd\si@unt@checkstack\endcsname}{#1}%
-%    \end{macrocode}
-% A count is kept of the number of \emph{units} added to each stack.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{#1}%
-  \renewcommand*{\si@tempb}{unit}%
-  \ifx\si@tempa\si@tempb
-    \expandafter\si@unt@inccnt
-  \fi
-%    \end{macrocode}
-% If a space is added, it is actually held until the next add.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_join_complex:}
+% For adding the complex part to the main part of a number.
 %    \begin{macrocode}
-  \renewcommand*{\si@tempb}{space}%
-  \ifx\si@tempa\si@tempb
-    \expandafter\si@unt@holdspace
-  \else
-    \expandafter\si@unt@addstack
-  \fi
-  {#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@inccnt}
-% The appropriate counter is added to.
-%    \begin{macrocode}
-\newcommand*{\si@unt@inccnt}{%
-  \expandafter\advance
-    \csname si@unt@unitcnt\si@unt@checkstack\endcsname
-    \@ne\relax}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@spacestack}
-%\begin{macro}{\si@unt@spacestacka}
-%\begin{macro}{\si@unt@spacestackb}
-% The stacked material needs somewhere to live.
-%    \begin{macrocode}
-\newcommand*{\si@unt@spacestack}{}
-\newcommand*{\si@unt@spacestacka}{}
-\newcommand*{\si@unt@spacestackb}{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@holdspace}
-%\begin{macro}{\si@unt@addstack}
-%\darg{token}
-% Depending on the nature of the addition, it is either held or added
-% to the stack.  For the ``b'' space stack, a check is made to ensure
-% that a space cannot be added before the first item.
-%    \begin{macrocode}
-\newcommand*{\si@unt@holdspace}[1]{%
-  \renewcommand*{\si@tempa}{b}%
-  \edef\si@tempb{\si@unt@checkstack}%
-  \ifx\si@tempa\si@tempb
-    \ifx\@empty\si@unt@stackb\@empty
-    \else
-      \protected@edef\si@unt@spacestackb{#1}%
-    \fi
-  \else
-    \protected@edef\si@unt@spacestacka{#1}%
-  \fi}
-\newcommand*{\si@unt@addstack}[1]{%
-  \expandafter\protected@edef
-    \csname si@unt@stack\si@unt@checkstack\endcsname
-    {\csname si@unt@stack\si@unt@checkstack\endcsname
-     \csname si@unt@spacestack\si@unt@checkstack\endcsname#1}%
-  \expandafter\renewcommand\expandafter*\expandafter{%
-    \csname si@unt@spacestack\si@unt@checkstack\endcsname}{}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@stackout}
-% The stack contents are actually typeset here.  First the spacing
-% between units and values is added.
-%    \begin{macrocode}
-\newcommand*{\si@unt@stackout}{%
-  \si@unt@litouttrue
-  \ifsi@frac
-    \expandafter\si@unt@fracout
-  \else
-    \expandafter\si@unt@normout
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@checkstack}
-% Which stack is in use needs to be tested.
-%    \begin{macrocode}
-\newcommand*{\si@unt@checkstack}{%
-  \ifsi@frac
-    \ifsi@unt@per
-      \expandafter\expandafter\expandafter b%
-    \else
-      \expandafter\expandafter\expandafter a%
-    \fi
-  \else
-    \expandafter a%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@spaceout}
-% The space before a unit might not be needed, so it crops up a few
-% times in the output routine.
-%    \begin{macrocode}
-\newcommand*{\si@unt@spaceout}{%
-   \ensuremath{\si@unt@spstack}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@prefixout}
-% If the prefix counter is not zero, then there is something to
-% typeset.
-%    \begin{macrocode}
-\newcommand*{\si@unt@prefixout}{%
-  \ifnum\si@unt@prefixcnt=\z@\relax\else
-    \ifsi@unt@num
-      \si@out{\ensuremath{{}\si@prefixproduct{}}}%
-    \fi
-    \si@unt@stackvalsep
-    \let\si@expbase\si@prefixbase
-    \num[fixdp=false]{e\the\si@unt@prefixcnt}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@normout}
-% The normal output mode is set up here; nothing much needs to be
-% done as there is no need for complex checks.
-%    \begin{macrocode}
-\newcommand*{\si@unt@normout}{%
-  \si@unt@prefixout
-  \si@unt@spaceout
-  \expandafter\si@unt@out\expandafter{\si@unt@stacka}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@fracout}
-% For fractions, some checks are needed.
-%    \begin{macrocode}
-\newcommand*{\si@unt@fracout}{%
-  \si@unt@notambig
-  \ifx\@empty\si@unt@stacka\@empty
-    \ifx\@empty\si@unt@stackb\@empty
-      \ifsi@unt@litout\else
-        \si@log@err{Empty fractional unit}{The unit
-          argument\MessageBreak given does not contain any
-          symbols}%
-      \fi
-    \else
-%    \end{macrocode}
-% With an empty numerator, no space is added
-%    \begin{macrocode}
-      \ifsi@slash
-        \si@unt@prefixout
-        \si@frac{}{\si@unt@stackb}%
-      \else
-        \si@unt@prefixout
-        \si@unt@spaceout
-        \si@frac{1}{\si@unt@stackb}%
-      \fi
-    \fi
-  \else
-%    \end{macrocode}
-% If the denominator is empty, then the usual output system can be
-% used.
-%    \begin{macrocode}
-    \ifx\@empty\si@unt@stackb\@empty
-      \si@unt@normout
-    \else
-      \si@unt@prefixout
-      \si@unt@spaceout
-      \si@frac{\si@unt@stacka}{\si@unt@stackb}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@notambig}
-%\begin{macro}{\si@unt@notabg}
-% A trap is set for adding brackets to units using a slash, when more
-% than one unit is in the denominator.
-%    \begin{macrocode}
-\newcommand*{\si@unt@notambig}{%
-  \ifnum\si@unt@unitcntb>\@ne\relax
-    \ifsi@slash
-        \ifsi@trapambigfrac
-          \expandafter\expandafter\expandafter\expandafter
-            \expandafter\expandafter\expandafter\si@unt@notabg
-        \fi
-    \fi
-  \fi}
-\newcommand*{\si@unt@notabg}{%
-  \protected@edef\si@unt@stackb{\si@openfrac\si@unt@stackb
-    \si@closefrac}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%
-%\begin{macro}{\si@unt@out}
-%\changes{v1.0d}{2008/06/25}{Sanitise one level of unit input
-%  only}
-%\darg{unit}
-% The final part of the units system is the output routine.  This has
-% to cope with units not only as macros but also as direct input
-% (\SIstyle-type input).  Non-Latin characters are also handled
-% cleanly.  The \cs{scantokens} system deals with everything except
-% full stops; these are left out so that a single level system can be
-% used \latin{via} a token register.
-%    \begin{macrocode}
-\begingroup
-  \catcode`\~=\active
-  \catcode`\.=\active
-  \gdef\si@unt@out#1{%
-    \si@temptoks{#1}%
-    \si@unt@fullstop
-    \def.{\ensuremath{\si@unitsep}}%
-    \def~{\ensuremath{\si@unitspace}}%
-    \expandafter\protected@edef\expandafter\si@tempa
-      \expandafter{\the\si@temptoks}%
-    \begingroup
-      \si@unt@nonlatin
-      \makeatletter
-      \endlinechar\m@ne
-      \expandafter\si@out\expandafter{%
-        \expandafter\scantokens\expandafter{\si@tempa}}%
-    \endgroup}
-\endgroup
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@fullstop}
-%\begin{macro}{\si@unt@stp}
-% Two macros modified from \pkg{kvsetkeys} to deal with a single
-% level of active full stops only.
-%    \begin{macrocode}
-\begingroup
-  \catcode`\.=\active
-  \catcode`\&=12\relax
-  \begingroup
-    \lccode`\.=`\.\relax
-    \lccode`\&=`\.\relax
-  \lowercase{\endgroup
-    \gdef\si@unt@fullstop{%
-      \si@temptoks\expandafter{\expandafter}\expandafter
-      \si@unt@stp\the\si@temptoks&\@nil}
-  \gdef\si@unt@stp#1&#2\@nil{%
-    \edef\si@tempa{\the\si@temptoks}%
-    \ifx\si@tempa\@empty
-      \expandafter\@firstoftwo
-    \else
-      \expandafter\@secondoftwo
-    \fi
-      {\si@temptoks{#1}}
-      {\si@temptoks\expandafter{\the\si@temptoks.#1}}%
-    \si@ifmtarg{#2}
-      {}
-      {\si@unt@stp#2\@nil}}}
-\endgroup
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@unt@nonlatin}
-% To handle non-Latin symbols in the input, a single macro is
-% provided.  If \XeTeX\ is in use, this can be detected immediately.
-%    \begin{macrocode}
-\newcommand*{\si@unt@nonlatin}{}
-\ifdefined\XeTeXrevision
-  \renewcommand*{\si@unt@nonlatin}{%
-    \catcode176=\active
-    \catcode181=\active
-    \catcode197=\active
-    \si@unt@sym{176}{\si@sym@degree}%
-    \si@unt@sym{181}{\si@sym@mu}%
-    \si@unt@sym{197}{\si@sym@ringA}}%
-\fi
-%    \end{macrocode}
-% If \pkg{inputenc} has been loaded, then a check is made that the
-% encoding is correct.  If all is well, the non-Latin symbols are
-% handled.  The degree symbol is character 176, the micro
-% symbol is character 181 and ring capital A is character 197 in
-% latin1.
-%    \begin{macrocode}
-\AtBeginDocument{
-  \@ifpackageloaded{inputenc}
-    {\@for\si@tempa:=latin1,latin5,latin9\do{
-       \ifx\inputencodingname\si@tempa
-         \renewcommand*{\si@unt@nonlatin}{%
-           \catcode176=\active
-           \catcode181=\active
-           \catcode197=\active
-           \si@unt@sym{176}{\si@sym@degree}%
-           \si@unt@sym{181}{\si@sym@mu}%
-           \si@unt@sym{197}{\si@sym@ringA}}%
-       \fi}}
-    {}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@unt@sym}
-%\darg{charcode}
-% A macro for declaring symbols: a copy of \cs{DeclareInputMath} from
-% \pkg{inputenc}.
-%    \begin{macrocode}
-\newcommand*{\si@unt@sym}[1]{%
-  \bgroup
-    \uccode`\~#1%
-    \uppercase{%
-      \egroup
-      \def~}}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_complex: {
+  \_siunitx_number_format_sign_complex:
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa } 
+    {
+      \_siunitx_number_format_brackets:n { mantissa }
+      \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-result } 
+        \_l_siunitx_tmpa_tl 
+      \prop_get:NnN \_l_siunitx_number_out_prop { complex-result }
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NT \_l_siunitx_tmpb_tl
+        {
+          \prop_get:NnN \_l_siunitx_number_out_prop { complex }
+            \_l_siunitx_tmpb_tl
+        }  
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop { mantissa-result } 
+        \_l_siunitx_tmpa_tl
+      \prop_put:Nnn \_l_siunitx_number_out_prop { mantissa-bracket } 
+        { true }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %
-%\begin{macro}{\kilogram}
-%\begin{macro}{\metre}
-%\begin{macro}{\meter}
-%\begin{macro}{\mole}
-%\begin{macro}{\kelvin}
-%\begin{macro}{\candela}
-%\begin{macro}{\second}
-%\begin{macro}{\ampere}
-% With the system set up, the basic unit macros are implemented.  The
-% only units defined whatever options are given are the base SI
-% units.
+%\begin{macro}{\_siunitx_number_format_join_uncert:}
+%\begin{macro}{\_siunitx_number_format_join_uncert:n}
+%\begin{macro}[aux]{\_siunitx_number_format_join_uncert_pm:}
+% For adding separated uncertainties to the main part of a number.
 %    \begin{macrocode}
-\newunit{\kilogram}{kg}
-\newunit{\metre}{m}
-\newunit{\meter}{\metre}
-\newunit{\mole}{mol}
-\AtBeginDocument{\provideunit{\second}{s}}
-\newunit{\ampere}{A}
-\newunit{\kelvin}{K}
-\newunit{\candela}{cd}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert: {
+  \_siunitx_number_format_join_uncert:n { mantissa }
+  \_siunitx_number_format_join_uncert:n { complex }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} 
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl  
+    {
+      \prop_get:NnN \_l_siunitx_number_out_prop { #1 -uncertainty }
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NTF \_l_siunitx_tmpb_tl 
+        { \_siunitx_number_format_copy:nn {#1} { #1 -result } } 
+        {
+          \bool_if:NT \_l_siunitx_uncert_sep_bool
+            { \_siunitx_number_format_join_uncert_pm: }
+          \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result } 
+            \_l_siunitx_tmpa_tl
+          \prop_put:Nnn \_l_siunitx_number_out_prop { #1 -bracket } 
+            { true }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert_pm: {
+  \bool_if:NTF \_l_siunitx_tight_bool 
+    { 
+      \tl_put_left:Nn \_l_siunitx_tmpb_tl 
+        { \_siunitx_ensuremath:n { { \pm } } } 
+    }
+    { 
+      \tl_put_left:Nn \_l_siunitx_tmpb_tl 
+        { \_siunitx_ensuremath:n { { } \pm { } } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_reassemble:}
+% The integer, decimal and any non-separated uncertainty parts are 
+% put back together. This gives a \enquote{minimal} unit which cannot
+% need any brackets or repeated units (if applicable). If the 
+% uncertainty is separate, it is stored at this stage pending later 
+% re-attachment.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_reassemble: {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { mantissa } 
+    {
+      \_siunitx_number_format_group:n { mantissa }
+      \_siunitx_number_format_uncertainty:n { mantissa }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { complex } 
+    {
+      \_siunitx_number_format_group:n { complex }
+      \_siunitx_number_format_uncertainty:n { complex }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent } 
+    { \_siunitx_number_format_group:n { exponent } }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_format_sign:n}
+%\begin{macro}{\_siunitx_number_format_sign_complex:}
+%\begin{macro}[aux]{\_siunitx_number_format_sign_complex:n}
+% Some simple sign manipulation: for tight signs, a little shuffling.
+% In the complex number case, there is a need for a correction to get
+% the right formatting in text mode. For speed reasons, this is done in
+% a separate function.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop {#1} 
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { #1 -sign } 
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl 
+        {
+          \bool_if:NT \_l_siunitx_tight_bool 
+            {
+              \tl_set:Nx \_l_siunitx_tmpa_tl 
+                { { \exp_not:V \_l_siunitx_tmpa_tl } }
+            }
+          \tl_clear:N \_l_siunitx_tmpb_tl
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl 
+            \_l_siunitx_tmpa_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { #1 -sign } 
+            \_l_siunitx_tmpb_tl        
+          \prop_get:NnN \_l_siunitx_number_out_prop {#1} 
+            \_l_siunitx_tmpa_tl   
+          \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl      
+          \prop_put:NnV \_l_siunitx_number_out_prop {#1} 
+            \_l_siunitx_tmpa_tl
+          \prop_get:NnN \_l_siunitx_number_out_prop { #1 -result }
+            \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl     
+            {
+              \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl      
+              \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result } 
+                \_l_siunitx_tmpa_tl
+            }  
+      }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign_complex: {
+  \_siunitx_number_format_sign_complex:n { complex }
+  \_siunitx_number_format_sign_complex:n { complex-result }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign_complex:n #1  {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop {#1} 
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { complex-sign } 
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \bool_if:NTF \_l_siunitx_tight_bool 
+            {
+              \tl_set:Nx \_l_siunitx_tmpa_tl 
+                { { \exp_not:V \_l_siunitx_tmpa_tl } }
+            }
+            {
+              \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa }
+                {
+                  \tl_set:Nx \_l_siunitx_tmpa_tl
+                    { { } \exp_not:V \_l_siunitx_tmpa_tl { } }
+                }
+            }
+          \tl_clear:N \_l_siunitx_tmpb_tl
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl 
+            \_l_siunitx_tmpa_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { complex-sign } 
+            \_l_siunitx_tmpb_tl        
+          \prop_get:NnN \_l_siunitx_number_out_prop {#1} 
+            \_l_siunitx_tmpa_tl   
+          \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl      
+          \prop_put:NnV \_l_siunitx_number_out_prop {#1} 
+            \_l_siunitx_tmpa_tl 
+      }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\Square}
-%\changes{v1.1b}{2008/10/12}{Only defined if not otherwise available}
-%\begin{macro}{\ssquare}
-%\begin{macro}{\squared}
-%\begin{macro}{\cubic}
-%\begin{macro}{\cubed}
-% Unlike multiples (which can be skipped if needed), the basic powers
-% are also always defined.
+%
+%\begin{macro}{\_siunitx_number_format_uncertainty:n}
+%\begin{macro}{\_siunitx_number_format_uncertainty_joined:n}
+%\begin{macro}{\_siunitx_number_format_uncertainty_sep:n}
+% Uncertainty output varies depending on whether there is a need to 
+% separate the error form the number in the output. 
 %    \begin{macrocode}
-\AtBeginDocument{
-  \@ifundefined{Square}{%
-    \newpower{\Square}{2}}{}}
-\newpower{\ssquare}{2}
-\newpower[post]{\squared}{2}
-\newpower{\cubic}{3}
-\newpower[post]{\cubed}{3}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_uncertainty:n #1 {
+  \prop_if_in:NnTF \_l_siunitx_number_in_prop { #1 -uncertainty } 
+    {
+      \bool_if:NTF \_l_siunitx_uncert_sep_bool 
+        { \_siunitx_number_format_uncertainty_sep:n {#1} }
+        { \_siunitx_number_format_uncertainty_joined:n {#1} }
+      \_siunitx_number_format_join_uncert:
+    }
+    { \_siunitx_number_format_copy:nn {#1} { #1 -result } }
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_format_uncertainty_joined:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -uncertainty }
+    \_l_siunitx_tmpa_tl
+  \prop_del:Nn \_l_siunitx_number_in_prop { #1 -uncertainty }
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl 
+    \_l_siunitx_output_uncert_open_tl
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_uncert_sep_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_output_uncert_close_tl
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpb_tl
+  \tl_put_right:NV \_l_siunitx_tmpb_tl \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpb_tl
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_number_format_uncertainty_sep:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -integer } 
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop 
+        { #1 -uncertainty-integer }
+        {
+          \prop_put:Nnn \_l_siunitx_number_out_prop 
+            { #1 -uncertainty-integer } { 0 }
+        }
+    }
+    \_siunitx_number_format_group:n { #1 -uncertainty }
+    \prop_put:NnV \_l_siunitx_number_out_prop { #1 -uncertainty }
+      \_l_siunitx_tmpa_tl
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Numerical output}
+%
+% The outer level of number processing for actually printing things.
+% 
+%\begin{macro}{\_l_siunitx_number_out_tl}
+%\begin{macro}{\_l_siunitx_number_out_saved_tl}
+% The final result, plus a version for loops.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_number_out_tl
+\tl_new:N \_l_siunitx_number_out_saved_tl
+%    \end{macrocode}
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\_l_siunitx_number_fraction_tl}
+% Fractions need to be build separately, so that there is no problem 
+% with stack order.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_number_fraction_tl
+%    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\tothe}
-%\begin{macro}{\raiseto}
-% The user macros for arbitraty powers are simple
-% calling macros to a common internal macro.
+%
+%\begin{macro}{\_l_siunitx_number_compound_bool}
+% To help with brackets.
 %    \begin{macrocode}
-\newcommand*{\tothe}{\si@tothe{\tothe}}
-\newcommand*{\raiseto}{\si@tothe{\raiseto}}
+\bool_new:N \_l_siunitx_number_compound_bool
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_quotient_mode_tl}
+% The action for quotients is stored as a token list variable.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_quotient_mode_tl
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@tothe}
-%\begin{macro}{\tothe@opt@si}
-%\begin{macro}{\raiseto@opt@si}
-%\darg{either \texttt{\cs{tothe}} or \texttt{\cs{raiseto}}}
-%\darg{number}
-% A macro for arbitrary powers, which comes after the unit and so
-% needs to be marked as such.  Two fake option-storage macros are
-% created so that everything works correctly.
+%
+%\begin{macro}{\_siunitx_fraction:nn}
+% The function used for fractions should be stored here.
 %    \begin{macrocode}
-\newcommand*{\si@tothe}[2]{%
-  \ifsi@unt@littest
-    \expandafter\@gobbletwo
-  \else
-    \ifsi@unt@litout
-      \expandafter\expandafter\expandafter\si@unt@litpower
-    \else
-      \expandafter\expandafter\expandafter\si@unt@power
-    \fi
-  \fi
-  {#1}{#2}}
-\newcommand*{\tothe@opt@si}{post}
-\newcommand*{\raiseto@opt@si}{}
+\cs_set_protected:Npn \_siunitx_fraction:nn { }
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_output_quotient_tl}
+%\begin{macro}{\l_siunix_number_parse_bool}
+% Some options related to numbers at the output stage.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  fraction-function  .code:n     = 
+     { \cs_set_eq:NN \_siunitx_fraction:nn #1 },
+  output-product     .tl_set:N   = \_l_siunitx_output_product_tl,
+  output-quotient    .tl_set:N   = \_l_siunitx_output_quotient_tl,
+  parse-numbers      .bool_set:N = \_l_siunitx_number_parse_bool,
+  quotient-mode      .choice:,
+  quotient-mode / fraction .code:n = 
+    { \tl_set:Nn \_l_siunitx_quotient_mode_tl { fraction } },  
+  quotient-mode / symbol .code:n = 
+    { \tl_set:Nn \_l_siunitx_quotient_mode_tl { symbol } },
+}
+\keys_set:nn { siunitx } {
+  fraction-function = \frac,
+  output-product    = \times,
+  output-quotient   = /,
+  parse-numbers     = true,
+  quotient-mode     = symbol
+}
+%    \end{macrocode} 
 %\end{macro}
 %\end{macro}
-%
-%\subsection{Ranges}
-%
-%\begin{macro}{\numrange}
-%\changes{v1.2}{2009/01/22}{New user macro}
-%\begin{macro}{\SIrange}
-%\changes{v1.2}{2009/01/22}{New user macro}
-% Ranges are essentially just repeated calls to \cs{num} or \cs{SI}.
-% However, a nice wrapper is useful.
-%    \begin{macrocode}
-\si@newrobustcmd*{\numrange}[3][]{%
-  \begingroup
-    \sisetup{#1}%
-    \num{#2}%
-    \text{\si@tophrase}%
-    \num{#3}%
-  \endgroup
-}
-\si@newrobustcmd*{\SIrange}[4][]{%
-  \begingroup
-    \sisetup{#1}%
-    \ifsi@repeatunits
-      \SI{#2}{#4}%
-    \else
-      \ifsi@trapambigrange
-        \ensuremath{\si@openrange}%
-      \fi
-      \num{#2}%
-    \fi
-    \text{\si@tophrase}%
-    \ifsi@repeatunits
-      \SI{#3}{#4}%
-    \else
-      \ifsi@trapambigrange
-        \num{#3}%
-        \ensuremath{\si@closerange\si@valuesep}%
-        \si{#4}%
-      \else
-        \SI{#3}{#4}%
-      \fi
-    \fi
-  \endgroup
-}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%
-%\subsection{Locales}
-%\begin{macro}{\si@loc@load}
-%\begin{macro}{\si@loc@sisetup}
-%\darg{locale}
-% When loading a locale, the setup is saved rather than applied.
-% Anything other than simple settings should be inside
-% \cs{addtolocale}, which is already defined.
-%    \begin{macrocode}
-\newcommand*{\si@loc@load}[1]{%
-  \let\si@loc@sisetup\sisetup
-  \renewcommand*{\sisetup}[1]{%
-    \expandafter\gdef\csname si@loc@#1\endcsname{##1}}%
-  \si@loadfile{#1}%
-  \let\sisetup\si@loc@sisetup}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@loc@set}
-%\darg{locale}
-% Setting the locale transfers the settings to \cs{sisetup}, and runs
-% any extra macros.
-%    \begin{macrocode}
-\newcommand*{\si@loc@set}[1]{%
-  \ifcsname si@loc@#1\endcsname
-    \si@log@inf{Setting locale to `#1'}%
-    \expandafter\expandafter\expandafter\expandafter
-      \expandafter\expandafter\expandafter\si@temptoks
-      \expandafter\expandafter\expandafter\expandafter
-      \expandafter\expandafter\expandafter{%
-        \expandafter\csname si@loc@#1\endcsname}%
-    \expandafter\sisetup\expandafter{\the\si@temptoks}%
-    \ifcsname si@loc@#1@extra\endcsname
-      \csname si@loc@#1@extra\endcsname
-    \fi
-  \else
-    \ifcsname si@loc@#1@extra\endcsname
-      \si@log@inf{Setting locale to `#1'}%
-      \csname si@loc@#1@extra\endcsname
-    \else
-      \si@log@warn{Unknown locale `#1'}%
-    \fi
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@loc@ltol}
-%\changes{v1.0a}{2008/06/20}{\pkg{babel} support fixed for default
-%  document language}
-%\darg{list of locales and languages}
-% The necessary loading for language modules occurs.
-%    \begin{macrocode}
-\newcommand*{\si@loc@ltol}[1]{%
-  \def\si@tempa##1:##2\@nil{\si@loc@load{##1}}
-  \@for\si@tempb:=#1\do{%
-    \expandafter\si@tempa\si@tempb:\@nil}
-  \AtBeginDocument{
-    \@ifpackageloaded{babel}
-      {\def\si@tempa##1:##2:##3\@nil{%
-        \expandafter\addto\expandafter{%
-          \csname extras##2\endcsname}%
-          {\si@loc@set{##1}}}%
-       \@for\si@tempb:=#1\do{%
-         \expandafter\si@tempa\si@tempb::\@nil}%
-       \expandafter\selectlanguage\expandafter{\languagename}}
-      {\si@log@warn{babel not loaded \MessageBreak
-        loctolang option ignored}}}}
-\AtBeginDocument{
-  \@ifpackageloaded{babel}
-    {\renewcommand*{\si@loc@ltol}[1]{%
-       \def\si@tempa##1:##2\@nil{\si@loc@load{##1}}%
-       \@for\si@tempb:=#1\do{%
-         \expandafter\si@tempa\si@tempb:\@nil}%
-       \def\si@tempa##1:##2:##3\@nil{%
-         \expandafter\addto\expandafter{%
-           \csname extras##2\endcsname}%
-           {\si@loc@set{##1}}}%
-       \@for\si@tempb:=#1\do{%
-         \expandafter\si@tempa\si@tempb::\@nil}}}
-    {\renewcommand*{\si@loc@ltol}[1]{%
-       \si@log@warn{babel not loaded \MessageBreak
-         loctolang option ignored}}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\addtolocale}
-%\darg{locale}
-%\darg{commands}
-% Arbitrary macros may need to be added to the locale.
-%    \begin{macrocode}
-\newcommand*{\addtolocale}[2]{%
-  \si@addtocsname{si@loc@#1@extra}{#2}}
-%    \end{macrocode}
-%\end{macro}
-%
-%\subsection{Output routine}
-%\begin{macro}{\si@out}
-%\changes{v1.1}{2008/07/22}{Extended handling to subscripts}
-%\darg{text}
-% With all of the setup done, the text can finally be typeset.  This
-% is done inside a \cs{text} block, which takes care of
-% \cs{ensuremath}, \etc.  First of all, the various catcode settings
-% needed to get maths-in-text mode are made.  \cs{makeatletter} is
-% needed so that \cs{scantokens} still allows internal macros to
-% work.
-%    \begin{macrocode}
-\begingroup
-  \catcode`\^=\active
-  \catcode`\-=\active
-  \catcode`\_=\active
-  \gdef\si@out#1{%
-    \begingroup
-      \catcode`\^=\active
-      \catcode`\_=\active
-      \makeatletter
-      \endlinechar\m@ne
-%    \end{macrocode}
-%\changes{v1.0f}{2008/07/17}{Fixed bug with colour and spacing}
-% The various font families can now be set up.  First a check is made
-% in case there are nested calls to \cs{si@out@text}.
-%    \begin{macrocode}
-      \ifsi@fam@set\else
-        \expandafter\si@fam@set
-      \fi
-      \text{%
-        \si@colourcmd{\si@colour}%
-        \si@fam@italic\si@fam@bold\si@fam@text
-%    \end{macrocode}
-%  The correct mode is selected, and the input is handed off for
-%  typesetting.
-%    \begin{macrocode}
-        \ifsi@textmode
-          \expandafter\si@out@text
-        \else
-          \expandafter\si@out@maths
-        \fi
-        {\scantokens{#1}}}%
-    \endgroup
-    \check@mathfonts}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@out@text}
-%\begin{macro}{\si@out@maths}
-%\darg{text}
-% Output occurs with the correct changes to superscript behaviour.
-%    \begin{macrocode}
-  \gdef\si@out@text#1{%
-    \let^\si@out@sp
-    \let_\si@out@sb
-    \let\textsuperscript\si@out@sp
-    \let\textsubscript\si@out@sb
-    \catcode`\-=\active\relax
-    \let-\si@out@minus
-    #1}
-  \gdef\si@out@maths#1{%
-    \let^\sp
-    \let_\sb
-    \let\textsuperscript\sp
-    \let\textsubscript\sb
-    $\si@fam@maths{#1}$}
-\endgroup
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@out@sp}
-%\begin{macro}{\si@out@sb}
-%\darg{text}
-% \cs{textsuperscript} gives slightly different alignment of numbers
-% to using |^| in text mode.  To avoid this, a slightly different
-% definition is used.  Elsewhere \cs{textsuperscript} is used, as the
-% code above sorts out the text/maths mode issues. The same is done
-% for subscripts.
-%    \begin{macrocode}
-\newcommand*{\si@out@sp}[1]{\ensuremath{^{\text{#1}}}}
-\newcommand*{\si@out@sb}[1]{\ensuremath{_{\text{#1}}}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\si@out@minus}
-%\changes{v1.1j}{2008/12/22}{Fixed infinite loop with \pkg{breqn}}
-% An active minus sign is needed.
-%    \begin{macrocode}
-\newcommand*{\si@out@minus}{}
-\DeclareTextSymbolDefault{\si@out@minus}{TS1}
-\DeclareTextSymbol{\si@out@minus}{TS1}{61}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\ifsi@out@num}
-% A flag is needed to control output settings.  This will be
-% false unless inside \cs{si@out@num}.
-%    \begin{macrocode}
-\newif\ifsi@out@num
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@out@num}
-%\darg{number}
-% For numerical output, the default fonts are controlled slightly
-% differently to text output.
-%    \begin{macrocode}
-\newcommand*{\si@out@num}[1]{%
-  \begingroup
-    \si@out@numtrue
-    \si@out{#1}%
-  \endgroup}
+% 
+%\begin{macro}{\_siunitx_number_output:n}
+%\begin{macro}{\_siunitx_number_output:V}
+% The number output system simply sets up for the combined number and
+% unit system.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_number_output:n #1 {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_preunit_tl  
+  \_siunitx_combined_output:n {#1}
+}
+\cs_generate_variant:Nn \_siunitx_number_output:n { V }
 %    \end{macrocode}
 %\end{macro}
-%
-%\subsection{Finalisation}
-%\begin{macro}{\si@extension}
-%\begin{macro}{\si@fileprefix}
-% To keep the code easy to maintain, the reusable filename components
-% are macros rather than literals.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_output_bracket:}
+% Compound numbers may need brackets adding.
 %    \begin{macrocode}
-\newcommand*{\si@extension}{cfg}
-\newcommand*{\si@fileprefix}{si-}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_bracket: {
+  \bool_if:NF \_l_siunitx_error_bool 
+    {
+      \bool_if:NT \_l_siunitx_number_compound_bool 
+        { \_siunitx_number_format_brackets:n { result } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_output_color:}
+% If a colour needs to be set, it is recovered here and put into the
+% appropriate place.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_color: {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { color }
+    { 
+      \prop_get:NnN \_l_siunitx_number_out_prop { color } 
+        \_l_siunitx_number_color_tl
+    }    
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@ifl@aded}
-%\begin{macro}{\si@ifloaded}
-%\darg{package}
-% A bit of borrowing from the \LaTeX\ kernel.  A copy of
-% \cs{@ifl@aded} is needed as things aren't always done in the
-% preamble by \currpkg.
+%
+%\begin{macro}{\_siunitx_number_output_parse:n}
+%\begin{macro}{\_siunitx_number_output_parse:V}
+%\begin{macro}[aux]{\_siunitx_number_output_parse_aux:}
+% The parsing system just has to check if there are multiple parts to
+% worry about.
 %    \begin{macrocode}
-\newcommand*{\si@ifl@aded}{}
-\let\si@ifl@aded\@ifl@aded
-\newcommand*{\si@ifloaded}[1]{%
-  \si@ifl@aded\si@extension{\si@fileprefix#1}}
+\cs_set_protected:Npn \_siunitx_number_output_parse:n #1 {
+  \_siunitx_number_preprocess:n {#1}
+  \bool_if:NF \_l_siunitx_error_bool 
+    { 
+      \tl_if_empty:NTF \_l_siunitx_number_multi_tl 
+        { \_siunitx_number_output_parse_aux: }
+        { 
+          \use:c 
+            { _siunitx_number_output_ \_l_siunitx_number_multi_tl : } 
+        }
+    }
+}
+\cs_generate_variant:Nn \_siunitx_number_output_parse:n { V }
+%    \end{macrocode}
+% There are a few additional tests for printing partwise, as this is
+% only needed if there are brackets to add and these are not due to
+% an exponent. The test for an exponent is needed as this must force
+% the units to come at the end of the number, and there then have to 
+% be brackets in the output if there are any separate parts.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parse_aux: {
+  \_siunitx_number_in_parse:V \_l_siunitx_number_arg_tl 
+  \bool_if:NF \_l_siunitx_error_bool 
+    {
+      \_siunitx_number_process:
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        { \bool_set_true:N \_l_siunitx_brackets_bool }
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+      \bool_if:NTF \_l_siunitx_brackets_bool
+        { \_siunitx_number_output_single: }
+        { 
+          \prop_if_in:NnTF \_l_siunitx_number_out_prop 
+            { result-bracket }
+            { \_siunitx_number_output_parts: }
+            { \_siunitx_number_output_single: }
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@loadfile}
-%\darg{file}
-% Loading configuration files is handled here.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_output_parts:}
+%\begin{macro}[aux]{\_siunitx_number_output_parts_aux:}
+%\begin{macro}[aux]{\_siunitx_number_output_parts_aux:n}
+%\begin{macro}[aux]{\_siunitx_number_output_parts_print:n}
+% Printing numbers by parts is necessary when there are units to 
+% repeat. That means doing things that have already been done by the
+% number formatter again.
 %    \begin{macrocode}
-\newcommand*{\si@loadfile}[1]{%
-  \si@ifloaded{#1}{}
-    {\si@InputIfFileExists{\si@fileprefix#1.\si@extension}
-      {}
-      {\si@log@err{Failed to load file
-         \si@fileprefix#1.\si@extension}
-         {The configuration file requested could not be
-          found}}}}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts: {
+  \bool_if:nTF
+    {
+      \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+      \tl_if_empty_p:N \_l_siunitx_unit_tl 
+    }
+    { \_siunitx_number_output_single: }
+    { \_siunitx_number_output_parts_aux: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_aux: {
+  \bool_if:NTF \_l_siunitx_multi_repeat_bool
+    { 
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+        {
+          \_siunitx_number_output_parts_aux:n { mantissa }
+          \_siunitx_number_output_parts_aux:n { complex }
+        }
+      \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpa_tl  
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+            {
+              \tl_set_eq:NN \_l_siunitx_tmpb_tl 
+                \_l_siunitx_exponent_product_tl
+              \bool_if:NT \_l_siunitx_tight_bool 
+                {  
+                  \tl_set:Nx \_l_siunitx_tmpb_tl 
+                    { { \exp_not:V \_l_siunitx_tmpb_tl } }
+                }
+              \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+                \_l_siunitx_tmpb_tl
+              \prop_put:NnV \_l_siunitx_number_out_prop { exponent }
+                \_l_siunitx_tmpa_tl
+            }
+          \_siunitx_number_output_parts_print:n { exponent }
+        }
+    }
+    { \_siunitx_number_output_single: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_aux:n #1 {
+   \prop_if_in:NnT \_l_siunitx_number_out_prop {#1} 
+     { \_siunitx_number_output_parts_print:n {#1} }
+   \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -uncertainty } 
+     { 
+        \bool_if:NTF \_l_siunitx_tight_bool 
+          { 
+            \_siunitx_print:nn { number } 
+              { \_siunitx_ensuremath:n { { \pm } } } 
+          }
+          { 
+            \_siunitx_print:nn { number } 
+              { \_siunitx_ensuremath:n { { } \pm { } } } 
+          }
+       \_siunitx_number_output_parts_print:n { #1 -uncertainty } 
+     }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_print:n #1 {
+  \_siunitx_unit_output_pre_print:
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+  \_siunitx_unit_output_print:
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ifsi@outerinput}
-% At various points, the package needs to know if the
-% currently-read configuration file is the
-% outer one.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_number_output_product:}
+% For products, there may need to be the addition of brackets if there
+% are units about. When not repeating units, some work has to be done to
+% print everything correctly. The extra group here is necessary
+% otherwise looping will delete the units entirely!
 %    \begin{macrocode}
-\newif\ifsi@outerinput\si@outerinputtrue
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product: {
+  \bool_if:NTF \_l_siunitx_product_brackets_bool
+    { 
+      \bool_if:nTF
+        {
+          \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+          \tl_if_empty_p:N \_l_siunitx_unit_tl 
+        }
+        { \_siunitx_number_output_product_aux: }
+        { \_siunitx_number_output_product_brackets: }
+    }
+    { 
+      \bool_if:NTF \_l_siunitx_product_repeat_bool
+        { \_siunitx_number_output_product_aux: }
+        { 
+          \_siunitx_unit_output_pre_print:
+          \tl_set_eq:NN \_l_siunitx_unit_saved_tl \_l_siunitx_unit_tl
+          \tl_clear:N \_l_siunitx_pre_unit_tl
+          \tl_clear:N \_l_siunitx_unit_tl
+          \group_begin:  
+            \_siunitx_number_output_product_aux:
+          \group_end:   
+          \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_saved_tl
+          \_siunitx_unit_output_print:
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@InputIfFileExists}
-% To allow reading configuration files after the start of the
-% document, a private copy of \cs{InputIfFileExists} is needed.  The
-% main macro here simply checks if the modified version is needed.
-%    \begin{macrocode}
-\let\si@InputIfFileExists\InputIfFileExists
-\AtBeginDocument{
-  \renewcommand*{\si@InputIfFileExists}{%
-    \ifsi@outerinput
-      \expandafter\si@outerinput
-    \else
-      \expandafter\InputIfFileExists
-    \fi}}
+%\begin{macro}[aux]{\_siunitx_number_output_product_brackets:}
+% When printing products that have to be bracketed, there is a need to
+% shuffle the units about a bit.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product_brackets: {
+  \_siunitx_unit_output_pre_print:
+  \_siunitx_print:nn { number } 
+    { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+  \nobreak
+  \tl_set_eq:NN \_l_siunitx_unit_saved_tl \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_pre_unit_tl
+  \tl_clear:N \_l_siunitx_unit_tl
+  \_siunitx_number_output_product_aux:
+  \nobreak
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_saved_tl
+  \_siunitx_print:nn { number } 
+    { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+  \_siunitx_unit_output_print:
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\si@outerinput}
-%\darg{file}
-%\darg{true-code}
-%\darg{false-code}
-% The outer call to load a file needs to set |@| to a letter and turn
-% of printing using \cs{nullfont}.
-%    \begin{macrocode}
-\newcommand*{\si@outerinput}[3]{%
-  \makeatletter
-  \nullfont
-  \si@outerinputfalse
-  \IfFileExists{#1}%
-    {#2\@addtofilelist{#1}\@@input \@filef@und\normalsize}
-    {#3}%
-  \normalsize
-  \makeatother}
+%\begin{macro}[aux]{\_siunitx_number_output_product_aux:}
+% Printing the products needs a looping function.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product_aux: {
+  \bool_set_true:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_preprocess:V \_l_siunitx_number_arg_tl
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \tl_if_empty:NTF \_l_siunitx_number_multi_tl
+        { \_siunitx_number_output_parse_aux: }
+        { \_siunitx_number_output_quotient: }
+      \tl_if_empty:NF \_l_siunitx_number_next_tl
+        {  
+          \bool_if:NTF \_l_siunitx_tight_bool
+            {
+              \_siunitx_print:nn { number } 
+                { 
+                  \_siunitx_ensuremath:n 
+                    { \_l_siunitx_output_product_tl } 
+                }
+            }    
+            {
+              \_siunitx_print:nn  { number } 
+                { 
+                  \_siunitx_ensuremath:n 
+                    { { } \_l_siunitx_output_product_tl { } }
+                }
+            } 
+          \_siunitx_number_output_parse:V \_l_siunitx_number_next_tl  
+        }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\requiresiconfigs}
-%\darg{config-file}
-% The configuration files depend on each other.
-%    \begin{macrocode}
-\newcommand*{\requiresiconfigs}[1]{%
-  \@for\si@tempb:=#1\do{\si@loadfile{\si@tempb}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@loademfile}
-%\darg{file}
-% For emulation files, an additional check is made.
-%    \begin{macrocode}
-\newcommand*{\si@loademfile}[1]{%
-  \@ifpackageloaded{#1}
-    {\si@log@err{Emulation clash for package `#1'}
-      {You have asked for emulation of package
-       `#1'\MessageBreak
-       (perhaps by giving siunitx a back-compatibility
-       option)\MessageBreak but the package is already
-       loaded!}}
-    {\si@loadfile{#1}}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@emclash}
-%\darg{package}
-%\darg{package}
-% A macro for emulation clashes.
-%    \begin{macrocode}
-\newcommand*{\si@emclash}[2]{%
-  \si@log@err{Emulation clash: `#1' and `#2'}
-    {You have asked for emulation of package `#1'\MessageBreak
-     but have already loaded emulation of `#2'}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@emulating}
-%\darg{package}
-%\darg{version}
-% For packages that are emulated, the \LaTeX\ mechanism to prevent
-% re-loading is used.  The list of packages to check at the start
-% of the document also has to be altered.
-%    \begin{macrocode}
-\newcommand*{\si@emulating}[2]{%
-  \@namedef{ver@#1.sty}{#2 siunitx emulation of #1}%
-  \let\si@tempa\si@blockpkgs
-  \renewcommand*{\si@blockpkgs}{}%
-  \@for\si@tempb:=\si@tempa\do{%
-    \renewcommand*{\si@tempa}{#1}%
-    \ifx\si@tempa\si@tempb\else
-      \lowercase{\edef\si@tempa{#1}}%
-      \lowercase{\edef\si@tempc{\si@tempb}}%
-      \ifx\si@tempa\si@tempc
-        \@namedef{ver@\si@tempc.sty}{#2 siunitx emulation of
-          #1}%
-      \else
-        \si@addtolist{\si@blockpkgs}{\si@tempb}%
-      \fi
-    \fi}%
-  \let\si@tempa\si@checkpkgs
-  \renewcommand*{\si@checkpkgs}{}%
-  \renewcommand*{\si@tempb}{#1}%
-  \@for\si@tempc:=\si@tempa\do{%
-    \ifx\si@tempb\si@tempc\else
-      \si@addtolist{\si@checkpkgs}{\si@tempc}%
-    \fi}}
-%    \end{macrocode}
-%\end{macro}
-% With the \currpkg kernel macros defined, the package can now run
-% through finalisation.  First, the default key values are set. The
-% user options are then processed.
+%
+%\begin{macro}{\_siunitx_number_output_quotient:}
+% For quotients, there are two options.
 %    \begin{macrocode}
-\sisetup{
-  addsign=none,
-  allowlitunits=true,
-  allowzeroexp=false,
-  angformat=unchanged,
-  astroang=false,%(
-  closeerr=),%(
-  closefrac=),%(
-  closerange=),
-  colour=black,
-  colourall=false,
-  colourneg=false,
-  decimalsymbol=fullstop,
-  detectdisplay=true,
-  digitsep=thin,
-  dp=3,
-  eVcorra=0.3ex,
-  eVcorrb=0ex,
-  errspace=none,
-  fixdp=false,
-  inlinebold=text,
-  load=default,
-  mathsrm=mathrm,
-  mathssf=mathsf,
-  mathstt=mathtt,
-  mode=maths,
-  negcolour=red,
-  noload={},
-  numaddn={},%(
-  numcloseerr=),
-  numdecimal={.,},
-  numdigits=0123456789,
-  numdiv=/,
-  numexp=eEdD,
-  numgobble={},
-  numopenerr=(,%)
-  numprod=x,
-  numsign=+-\pm\mp,
-  obeybold=false,
-  obeyitalic=false,
-  obeymode=false,
-  openerr=(,%)
-  openfrac=(,%)
-  openrange=(,%
-  padangle=small,
-  padnumber=lead,
-  per=reciprocal,
-  prefixbase=ten,
-  prefixproduct=times,
-  prefixsymbolic=true,
-  prespace=false,
-  redefsymbols=true,
-  repeatunits=true,
-  retainplus=false,
-  seperr=false,
-  sepfour=false,
-  sign=plus,
-  slash=slash,
-  stickyper=false,
-  strictarc=true,
-  tabalignexp=true,
-  tabautofit=false,
-  tabformat=3.2,
-  tabnumalign=centredecimal,
-  tabparseonly=false,
-  tabtextalign=centre,
-  tabunitalign=left,
-  textrm=rmfamily,
-  textsf=sffamily,
-  texttt=ttfamily,
-  tightpm=false,
-  tophrase=to,
-  trapambigerr=true,
-  trapambigfrac=true,
-  trapambigrange=true,
-  unitsep=thin,
-  valuesep=thin,
-  xspace=false}
-\ProcessOptionsX[si]<key>
-%    \end{macrocode}
-% A check is now made so that emulation takes place one file at a
-% time, and that each file is loaded only once.
-%    \begin{macrocode}
-\ifx\@empty\si@emulate\@empty\else
-  \@for\si@tempa:=\si@emulate\do{%
-    \expandafter\si@loademfile\expandafter{\si@tempa}}
-\fi
-%    \end{macrocode}
-%\begin{macro}{\si@expanddefault}
-% For turning the list of default choices into a loadable list.
-%    \begin{macrocode}
-\newcommand*{\si@expanddefault}[2]{%
-  \expandafter\ifx\expandafter\@empty\csname si@#1\endcsname
-    \@empty
-  \else
-    \renewcommand*{\si@tempb}{default}%
-    \renewcommand*{\si@tempc}{}%
-    \expandafter\@for\expandafter\si@tempa\expandafter
-      :\expandafter=\csname si@#1\endcsname\do{%
-      \ifx\si@tempa\si@tempb
-        \si@addtolist{\si@tempc}{#2}%
-      \else
-        \si@addtolist{\si@tempc}{\si@tempa}%
-      \fi}
-    \expandafter\edef\csname si@#1\endcsname{\si@tempc}%
-    \expandafter\si@addtolist\expandafter{%
-      \csname si@no#1\endcsname}%
-      {default}%
-    \renewcommand*{\si@tempc}{}%
-    \expandafter\@for\expandafter\si@tempa\expandafter
-      :\expandafter=\csname si@#1\endcsname\do{%
-      \si@switchfalse
-      \expandafter\@for\expandafter\si@tempb\expandafter
-        :\expandafter=\csname si@no#1\endcsname\do{%
-        \ifx\si@tempa\si@tempb
-          \si@switchtrue
-        \fi
-        \ifsi@switch\else
-          \si@addtolist{\si@tempc}{\si@tempa}%
-        \fi}}
-    \@for\si@tempa:=\si@tempc\do{%
-      \si@loadfile{\si@tempa}}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-% The configuration and abbreviation files are loaded.
-%    \begin{macrocode}
-\si@expanddefault{load}{prefix,named,addn,prefixed,accepted,%
-  physical,abbr}
-%    \end{macrocode}
-% The very last job is to load a local configuration file, if one
-% exists, and restore catcodes.
-%    \begin{macrocode}
-\IfFileExists{siunitx.cfg}
-  {\si@log@inf{Local configuration file found}%
-   \InputIfFileExists{siunitx.cfg}{}{}}
-  {}
-\si@catcodes
-%    \end{macrocode}
-%
-%\iffalse
-%</package>
-%\fi
-%
-%\section{Loadable modules}
-% To keep the package relatively clear, and to make maintenance
-% easier, the only units defined in the package itself are the base
-% units. Everything else is a loadable module (similar to the
-% approach in \unitsdef).
-%
-%\iffalse
-%<*prefix>
-%\fi
-%\subsection{Multiple prefixes}
-%\begin{macro}{\yocto}
-%\begin{macro}{\zepto}
-%\begin{macro}{\atto}
-%\begin{macro}{\femto}
-%\begin{macro}{\pico}
-%\begin{macro}{\nano}
-%\begin{macro}{\micro}
-%\begin{macro}{\Micro}
-%\begin{macro}{\milli}
-%\begin{macro}{\centi}
-%\begin{macro}{\deci}
-% The various SI multiple prefixes are defined here.  First the small
-% powers.
-%    \begin{macrocode}
-\ProvidesFile{si-prefix.cfg}
-  [2010/02/22 v1.4c siunitx: SI Multiple prefixes]
-\newprefix{\yocto}{-24}{y}
-\newprefix{\zepto}{-21}{z}
-\newprefix{\atto}{-18}{a}
-\newprefix{\femto}{-15}{f}
-\newprefix{\pico}{-12}{p}
-\newprefix{\nano}{-9}{n}
-%    \end{macrocode}
-% Some testing is needed for \unitsdef compatibility.
-%    \begin{macrocode}
-\ifsi@old@OHM
-  \newprefix{\Micro}{-6}{\si@sym@mu}
-\else
-  \ifsi@gensymb\else
-    \newprefix{\micro}{-6}{\si@sym@mu}
-  \fi
-\fi
-\newprefix{\milli}{-3}{m}
-\newprefix{\centi}{-2}{c}
-\newprefix{\deci}{-1}{d}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient: {
+  \use:c 
+    { _siunitx_number_output_quotient_ \_l_siunitx_quotient_mode_tl : }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_number_output_quotient_fraction:}
+% For fraction output, there are quite a lot of braces to construct,
+% unfortunately.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_fraction: {
+  \bool_set_false:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_output_quotient_aux_i:
+  \tl_set:Nx \_l_siunitx_number_out_tl 
+    { { \exp_not:V \_l_siunitx_number_numerator_tl } }
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { { \exp_not:V \_l_siunitx_number_denominator_tl } }
+  \tl_put_right:NV \_l_siunitx_number_out_tl \_l_siunitx_tmpa_tl
+  \tl_put_left:Nn \_l_siunitx_number_out_tl { \_siunitx_fraction:nn } 
+  \tl_set:Nx \_l_siunitx_number_out_tl 
+    {
+      \exp_not:N \ensuremath 
+        { \exp_not:V \_l_siunitx_number_out_tl }
+    }
+  \_siunitx_number_output_single_aux:
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_number_output_quotient_symbol:}
+% If a symbol is used for the division, the build process is less 
+% complex.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_symbol: {
+  \bool_set_true:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_output_quotient_aux_i:
+  \tl_set_eq:NN \_l_siunitx_number_out_tl 
+    \_l_siunitx_number_numerator_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_number_out_tl
+    \_l_siunitx_output_quotient_tl
+  \tl_put_right:NV \_l_siunitx_number_out_tl 
+    \_l_siunitx_number_denominator_tl 
+  \_siunitx_number_output_single_aux:
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}[aux]{\_siunitx_number_output_quotient_aux_i:}
+%\begin{macro}[aux]{\_siunitx_number_output_quotient_aux_ii:}
+% The two parts of the number are parsed and formatted.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_aux_i: {
+  \_siunitx_number_in_parse:V \_l_siunitx_number_numerator_tl
+  \_siunitx_number_output_quotient_aux_ii:
+  \_siunitx_number_output_color:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_number_numerator_tl 
+  \_siunitx_number_in_parse:V \_l_siunitx_number_denominator_tl
+  \_siunitx_number_output_quotient_aux_ii:
+  \prop_if_in:NnT \_l_siunitx_number_out_prop
+    { result-bracket-exponent }
+    { 
+      \prop_put:Nnn \_l_siunitx_number_out_prop { result-bracket } 
+        { true }
+    }
+  \_siunitx_number_output_bracket:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_number_denominator_tl    
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_aux_ii: { 
+  \_siunitx_number_process:
+  \_siunitx_number_format:
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_number_output_single:}
+%\begin{macro}[aux]{\_siunitx_number_output_single_aux:}
+% Printing a number with no multiple parts is easy. There is a check for
+% any units, which if present may force the number to have brackets 
+% added. there is then simply a short run to print the units and number.
+% The test for bracketing numbers does not happen if there is an 
+% exponent: if there is, any other parts will already be bracketed and
+% mathematically there is no need for brackets at this point. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_single: {
+  \bool_if:nF
+    {
+      \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+      \tl_if_empty_p:N \_l_siunitx_unit_tl 
+    }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { exponent }
+        { \_siunitx_number_format_brackets:n { result } }
+    }
+  \_siunitx_number_output_bracket:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result } 
+    \_l_siunitx_number_out_tl
+  \_siunitx_number_output_single_aux:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_single_aux: {
+  \_siunitx_unit_output_pre_print:
+  \_siunitx_print:nV { number } \_l_siunitx_number_out_tl
+  \_siunitx_unit_output_print:
+}
+%    \end{macrocode}
 %\end{macro}
+%\end{macro} 
+%
+%\subsection{Angles}
+%
+% Angles are a special case of numbers for two reasons. First, there
+% is always a unit, which is known in advance. Second, there are two
+% possible input syntaxes, "\ang{1.23}" and "\ang{1;2;3}". Both need
+% to be handled correctly.
+% 
+%\begin{macro}{\_l_siunitx_angle_degree_space_bool}
+%\begin{macro}{\_l_siunitx_angle_minute_space_bool}
+% The need for spaces between parts of an arc needs to be accommodated:
+% this is achieved by flagging up the need for such spaces using two
+% switches.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_angle_degree_space_bool
+\bool_new:N \_l_siunitx_angle_minute_space_bool
+%    \end{macrocode}
 %\end{macro}
+%\end{macro} 
+%
+%\begin{macro}{\_l_siunitx_angle_marker_box}
+%\begin{macro}{\_l_siunitx_angle_unit_box}
+%\begin{macro}{\_l_siunitx_angle_marker_dim}
+%\begin{macro}{\_l_siunitx_angle_unit_dim}
+% When creating astronomy-style angles, the decimal marker and angle 
+% symbol have to be boxed up and measured.
+%    \begin{macrocode}
+\box_new:N \_l_siunitx_angle_marker_box
+\box_new:N \_l_siunitx_angle_unit_box
+\dim_new:N \_l_siunitx_angle_marker_dim
+\dim_new:N \_l_siunitx_angle_unit_dim
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\deca}
-%\begin{macro}{\hecto}
-%\begin{macro}{\kilo}
-%\begin{macro}{\mega}
-%\begin{macro}{\giga}
-%\begin{macro}{\tera}
-%\begin{macro}{\peta}
-%\begin{macro}{\exa}
-%\begin{macro}{\zetta}
-%\begin{macro}{\yotta}
-% Now the large ones.
+%
+%\begin{macro}{\_l_siunitx_angle_degree_prop}
+%\begin{macro}{\_l_siunitx_angle_minute_prop}
+%\begin{macro}{\_l_siunitx_angle_second_prop}
+% As there are potentially three numbers to parse, three properly lists
+% are made available to hold the results. This allows the code to be
+% generalised, with only the name of the storage area varying.
 %    \begin{macrocode}
-\newprefix{\deca}{1}{da}
-\newprefix{\hecto}{2}{h}
-\newprefix{\kilo}{3}{k}
-\newprefix{\mega}{6}{M}
-\newprefix{\giga}{9}{G}
-\newprefix{\tera}{12}{T}
-\newprefix{\peta}{15}{P}
-\newprefix{\exa}{18}{E}
-\newprefix{\zetta}{21}{Z}
-\newprefix{\yotta}{24}{Y}
+\prop_new:N \_l_siunitx_angle_degree_prop
+\prop_new:N \_l_siunitx_angle_minute_prop
+\prop_new:N \_l_siunitx_angle_second_prop
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_angle_degree_zero_bool}
+%\begin{macro}{\_l_siunitx_angle_minute_zero_bool}
+%\begin{macro}{\_l_siunitx_angle_second_zero_bool}
+%\begin{macro}{\_l_siunitx_angle_arc_separator_tl}
+%\begin{macro}{\_l_siunitx_angle_astronomy_bool}
+%\begin{macro}{\_l_siunitx_angle_unit_separator_tl}
+% The angle-specific options are created here.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  add-arc-degree-zero       .bool_set:N = 
+    \_l_siunitx_angle_degree_zero_bool  , 
+  add-arc-minute-zero       .bool_set:N = 
+    \_l_siunitx_angle_minute_zero_bool  , 
+  add-arc-second-zero       .bool_set:N = 
+    \_l_siunitx_angle_second_zero_bool  ,
+  angle-symbol-over-decimal .bool_set:N = 
+    \_l_siunitx_angle_astronomy_bool    ,
+  arc-separator             .tl_set:N   = 
+    \_l_siunitx_angle_arc_separator_tl  ,
+  number-angle-separator    .tl_set:N   = 
+    \_l_siunitx_angle_unit_separator_tl , 
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\deka}
-% Apparently, ``deka'' is common in the US for deca.
+%
+%\begin{macro}{\_siunitx_angle_output:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_output_aux:nnn}
+% The input will have been split up by \pkg{xparse}, and so the various
+% possible inputs can be picked up. To keep to a minimal route through
+% the code, a decimal angle is simply treated like an arc, but with
+% any zero-filling disabled.
 %    \begin{macrocode}
-\newprefix{\deka}{1}{da}
+\cs_set_protected:Npn \_siunitx_angle_output:nnn #1#2#3 {
+  \_siunitx_angle_init:
+  \IfNoValueTF {#2}
+    { 
+      \bool_set_false:N \_l_siunitx_angle_minute_zero_bool
+      \bool_set_false:N \_l_siunitx_angle_second_zero_bool
+      \_siunitx_angle_output_aux:nnn {#1} { } { }
+    }
+    {
+      \IfNoValueTF {#3}
+        { \_siunitx_error:nn { invalid-arc-format } { #1 ; #2 } }
+        { \_siunitx_angle_output_aux:nnn {#1} {#2} {#3} }
+    }
+}
+\cs_set_protected:Npn \_siunitx_angle_output_aux:nnn #1#2#3 {
+  \tl_if_empty:nTF { #1#2#3 }
+    { \_siunitx_error:n { empty-arc } }
+    {
+      \bool_if:NTF \_l_siunitx_number_parse_bool
+        { \_siunitx_angle_parse:nnn {#1} {#2} {#3} }
+        { \_siunitx_angle_direct:nnn {#1} {#2} {#3} }
+    }
+}
 %    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\gram}
-%\begin{macro}{\kilogram}
-% As the base unit of mass is the kilogram, rather than the gram, a
-% bit of extra work is needed; by default the package only defines
-% \cs{kilogram}, but with the prefixes available, this is altered to
-% be \cs{kilo}\cs{gram}.  For that, the \cs{gram} must be defined first.
-%    \begin{macrocode}
-\newunit{\gram}{g}
-\renewunit{\kilogram}{\kilo\gram}
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_angle_init:}
+% The usual separation of initial storage resets.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_angle_init: {
+  \bool_set_false:N \_l_siunitx_angle_degree_space_bool
+  \bool_set_false:N \_l_siunitx_angle_minute_space_bool
+  \prop_clear:N \_l_siunitx_angle_degree_prop
+  \prop_clear:N \_l_siunitx_angle_minute_prop
+  \prop_clear:N \_l_siunitx_angle_second_prop
+  \tl_clear:N \_l_siunitx_preunit_tl 
+  \tl_set_eq:NN \_l_siunitx_number_unit_separator_tl 
+    \_l_siunitx_angle_unit_separator_tl
+  \cs_set_eq:NN \_siunitx_number_in_parse_more:N 
+    \_siunitx_number_in_parse_restricted:N 
+}
 %    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\iffalse
-%</prefix>
-%<*named>
-%\fi
-%\subsection{Derived units with specific names}
-%\begin{macro}{\becquerel}
-%\begin{macro}{\coulomb}
-%\begin{macro}{\farad}
-%\begin{macro}{\Gray}
-%\begin{macro}{\ggray}
-%\begin{macro}{\hertz}
-%\begin{macro}{\henry}
-%\begin{macro}{\joule}
-%\begin{macro}{\katal}
-%\begin{macro}{\lumen}
-%\begin{macro}{\lux}
-%\begin{macro}{\newton}
-% Derived units with specific names and symbols are defined.  Litre
-% is an awkward one, but here the UK standard is used.
+%
+%\begin{macro}{\_siunitx_angle_direct:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_direct_aux_i:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_direct_aux_ii:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_direct_aux_iii:nnn}
+% When printing an arc directly, there is still the need to fill in
+% any zero values required and to check the spacing is correct. That
+% is done using a chain approach, which is easy to implement and
+% reasonably clear.
 %    \begin{macrocode}
-\ProvidesFile{si-named.cfg}
-  [2010/02/22 v1.4c siunitx: SI Named units]
-\newunit{\becquerel}{Bq}
-\newunit{\coulomb}{C}
-\newunit{\farad}{F}
-\newunit{\Gray}{Gy}
-\newunit{\ggray}{Gy}
-\newunit{\hertz}{Hz}
-\newunit{\henry}{H}
-\newunit{\joule}{J}
-\newunit{\katal}{kat}
-\newunit{\lumen}{lm}
-\newunit{\lux}{lx}
-\newunit{\newton}{N}
+\cs_set_protected:Npn \_siunitx_angle_direct:nnn #1 {
+  \tl_if_empty:nTF {#1}
+    {
+      \bool_if:NTF \_l_siunitx_angle_degree_zero_bool
+        { \_siunitx_angle_direct_aux_i:nnn { 0 } }
+        { \_siunitx_angle_direct_aux_i:nnn { } }
+    }
+    { \_siunitx_angle_direct_aux_i:nnn {#1} }
+    
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_i:nnn #1#2 {
+  \tl_if_empty:nTF {#2}
+    {
+      \bool_if:NTF \_l_siunitx_angle_minte_zero_bool
+        { \_siunitx_angle_direct_aux_ii:nnn {#1} { 0 } }
+        { \_siunitx_angle_direct_aux_ii:nnn {#1} { } }
+    }
+    { \_siunitx_angle_direct_aux_ii:nnn {#1} {#2} }
+    
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_ii:nnn #1#2#3 {
+  \tl_if_empty:nTF {#3}
+    {
+      \bool_if:NTF \_l_siunitx_angle_second_zero_bool
+        { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} { 0 } }
+        { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} { } }
+    }
+    { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} {#3} }  
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_iii:nnn #1#2#3 {
+  \tl_if_empty:nF {#1}
+    {
+      \tl_if_empty:nF {#2#3}
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool }
+    }
+  \tl_if_empty:nF {#2}
+    {
+      \tl_if_empty:nF {#3}
+        { \bool_set_true:N \_l_siunitx_angle_minute_space_bool }
+    }
+  \_siunitx_angle_print_direct:nnn {#1} {#2} {#3}
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_angle_parse:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_parse_aux:nnn}
+%\begin{macro}{\_siunitx_angle_check_sign:}
+%\begin{macro}[aux]{\_siunitx_angle_check_sign:n}
+%\begin{macro}{\_siunitx_angle_zero_fill:}
+%\begin{macro}{\_siunitx_angle_sign_shuffle:nn}
+%\begin{macro}[aux]{\_siunitx_angle_sign_shuffle_aux:nnn}
+% Parsing an arc requires a number of stages. First, there is the
+% basic conversion of the input numbers into three property lists,
+% which will contain the data required. There is then a zero-filling
+% step, done here so that signs can be shuffled into the correct places.
+% After that, a check to make sure there is only one sign for an arc
+% before setting up the inter-part spacing and actually printing.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_angle_parse:nnn #1#2#3 {
+  \_siunitx_angle_parse_aux:nn {#1} { degree }
+  \_siunitx_angle_parse_aux:nn {#2} { minute }
+  \_siunitx_angle_parse_aux:nn {#3} { second }
+  \_siunitx_angle_check_sign:
+  \_siunitx_angle_zero_fill:
+  \prop_if_empty:NF \_l_siunitx_angle_degree_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool } 
+      \prop_if_empty:NF \_l_siunitx_angle_second_prop
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool } 
+    }
+  \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_second_prop
+        { \bool_set_true:N \_l_siunitx_angle_minute_space_bool } 
+    }
+  \_siunitx_angle_print: 
+}
+\cs_set_protected:Npn \_siunitx_angle_parse_aux:nn #1#2 {
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \tl_if_empty:nF {#1} 
+    { 
+      \_siunitx_number_in_init:
+      \_siunitx_number_in_parse_aux:n {#1} 
+    }
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign-deleted }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    { 
+      \prop_put:NnV \_l_siunitx_number_in_prop { mantissa-sign }
+        \_l_siunitx_tmpa_tl
+    }
+  \_siunitx_number_process:
+  \prop_set_eq:cN { _l_siunitx_angle_ #2 _prop } 
+    \_l_siunitx_number_in_prop 
+}
+%    \end{macrocode}
+% Only the highest-order part of an arc can have a sign. This is checked
+% now so that the shuffling code is easier to write.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_angle_check_sign: {
+  \prop_if_empty:NTF \_l_siunitx_angle_degree_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+        { \_siunitx_angle_check_sign_aux:n { second } }
+    }
+    {
+      \_siunitx_angle_check_sign_aux:n { minute }
+      \_siunitx_angle_check_sign_aux:n { second } 
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_check_sign_aux:n #1 {
+  \prop_if_in:cnTF { _l_siunitx_angle_ #1 _prop }
+    { mantissa-sign }
+    { \msg_error:nn { siunitx } { bad-arc-sign } }
+    {
+      \prop_if_in:cnT { _l_siunitx_angle_ #1 _prop }
+        { mantissa-sign-deleted }
+        { \msg_error:nn { siunitx } { bad-arc-sign } }
+    }
+}
+%    \end{macrocode}
+% Filling in the zero values is rather awkward as there are signs 
+% to worry about. There is therefore a shuffle to move them into the
+% correct places.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_angle_zero_fill: {
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_second_prop &&
+      \_l_siunitx_angle_second_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_second_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_second_prop { mantissa-integer }
+        { 0 }
+    }
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_minute_prop &&
+      \_l_siunitx_angle_minute_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_minute_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_minute_prop { mantissa-integer }
+        { 0 }
+      \_siunitx_angle_sign_shuffle:nn { second } { minute }  
+    }
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_degree_prop &&
+      \_l_siunitx_angle_degree_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_degree_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_degree_prop { mantissa-integer }
+        { 0 }
+      \_siunitx_angle_sign_shuffle:nn { second } { degree }
+      \_siunitx_angle_sign_shuffle:nn { minute } { degree }  
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_sign_shuffle:nn #1#2 {
+  \_siunitx_angle_sign_shuffle_aux:nnn {#1} {#2} { }
+  \_siunitx_angle_sign_shuffle_aux:nnn {#1} {#2} { -deleted }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_sign_shuffle_aux:nnn
+  #1#2#3 {
+  \prop_get:cnN { _l_siunitx_angle_ #1 _prop } { mantissa-sign #3 } 
+    \_l_siunitx_tmpa_tl
+  \prop_del:cn { _l_siunitx_angle_ #1 _prop } { mantissa-sign #3 } 
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_put:cnV { _l_siunitx_angle_ #2 _prop } { mantissa-sign #3 }
+        \_l_siunitx_tmpa_tl
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -10987,625 +8026,2544 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\ohm}
-%\begin{macro}{\Ohm}
-%\begin{macro}{\pascal}
-%\begin{macro}{\siemens}
-%\begin{macro}{\sievert}
-%\begin{macro}{\tesla}
-%\begin{macro}{\volt}
-%\begin{macro}{\watt}
-%\begin{macro}{\weber}
-% Some testing is needed for \unitsdef compatibility.
-%    \begin{macrocode}
-\ifsi@old@OHM
-  \newunit{\Ohm}{\si@sym@Omega}
-\else
-  \ifsi@gensymb\else
-%    \end{macrocode}
-% To be on the safe side, use \cs{provideunit}.
+%
+%\begin{macro}{\_siunitx_angle_print:}
+%\begin{macro}[aux]{\_siunitx_angle_print:nn}
+% The standard printing routine examines each part of the arc in turn
+% and either does a standard format or calls the special astronomy-style
+% routine. There may also be some spaces to add.
 %    \begin{macrocode}
-    \provideunit{\ohm}{\si@sym@Omega}
-  \fi
-\fi
-\newunit{\pascal}{Pa}
-\newunit{\siemens}{S}
-\newunit{\sievert}{Sv}
-\newunit{\tesla}{T}
-\newunit{\volt}{V}
-\newunit{\watt}{W}
-\newunit{\weber}{Wb}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print: {
+  \_siunitx_angle_print_aux:nn { degree } { \SIUnitSymbolDegree }
+  \bool_if:NT \_l_siunitx_angle_degree_space_bool
+    { 
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl } 
+    }
+  \_siunitx_angle_print_aux:nn { minute } { \SIUnitSymbolArcminute }
+  \bool_if:NT \_l_siunitx_angle_minute_space_bool
+    { 
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl } 
+    }
+  \_siunitx_angle_print_aux:nn { second } { \SIUnitSymbolArcsecond }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_aux:nn #1#2 {
+  \prop_if_empty:cF { _l_siunitx_angle_ #1 _prop }
+    {
+      \prop_set_eq:Nc \_l_siunitx_number_in_prop 
+        { _l_siunitx_angle_ #1 _prop }
+      \tl_set:Nn \_l_siunitx_unit_tl {#2}  
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+      \bool_if:NTF \_l_siunitx_angle_astronomy_bool
+        { \_siunitx_angle_print_astronomy: }
+        { \_siunitx_number_output_single: }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_angle_print_astronomy:}
+%\begin{macro}[aux]{\_siunitx_angle_print_astronomy_aux:}
+%\begin{macro}[aux]{\_siunitx_angle_print_astronomy_aux:n}
+%\begin{macro}[aux]{\_siunitx_angle_print_astronomy_marker:}
+%\begin{macro}[aux]{\_siunitx_angle_print_astronomy_unit:}
+% The first check for astronomy-style angles is that there is a decimal
+% marker in the current input: if not, the standard method can be used.
+% The method for the astronomy-style angle is not straight-forward, so
+% needs a little explanation. The integer and decimal parts of the
+% number are printed at each end of the function. In the middle is a 
+% method to centre the unit symbol on the decimal marker. This is done
+% by typesetting the two symbols and measuring their respective widths.
+% The two are then put into zero-width boxes, which allows them to be 
+% aligned horizontally centred with no vertical change. The larger
+% dimension is then used to reconstruct the appropriate width for the
+% final output. There is also a need to allow for the \cs{scriptspace}
+% added in after superscripts, which otherwise messes up the 
+% calculation.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy: {
+  \prop_if_in:NnTF \_l_siunitx_number_in_prop
+    { mantissa-decimal-marker }
+    { \_siunitx_angle_print_astronomy_aux: }
+    { \_siunitx_number_output_single: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_aux: {
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-integer }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl } 
+  \hbox_set:Nn \_l_siunitx_angle_marker_box
+    {
+      \_siunitx_print:nn { number } 
+        { \_siunitx_ensuremath:n { { \_l_siunitx_output_decimal_tl } } }
+    }
+  \hbox_set:Nn \_l_siunitx_angle_unit_box
+    {
+      \_siunitx_print:nV { unit } \_l_siunitx_unit_tl
+      \skip_horizontal:n { -\scriptspace }
+    }  
+  \_siunitx_angle_print_astronomy_aux:n { marker }
+  \_siunitx_angle_print_astronomy_aux:n { unit }
+  \hbox_set:Nn \_l_siunitx_angle_marker_box 
+    {
+      \box_use:N \_l_siunitx_angle_marker_box
+      \box_use:N \_l_siunitx_angle_unit_box
+    }
+  \dim_compare:nNnTF 
+    { \_l_siunitx_angle_marker_dim } > { \_l_siunitx_angle_unit_dim }
+    { \_siunitx_angle_print_astronomy_marker: }
+    { \_siunitx_angle_print_astronomy_unit: }
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-decimal }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl  
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl } 
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_aux:n #1 {
+  \dim_set:cn { _l_siunitx_angle_ #1 _dim  }
+    { \box_wd:c { _l_siunitx_angle_ #1 _box } }
+  \hbox_set_to_wd:cnn { _l_siunitx_angle_ #1 _box } { \c_zero_skip }
+    {
+      \tex_hss:D
+      \hbox_unpack:c { _l_siunitx_angle_ #1_box }
+      \tex_hss:D 
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_marker: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_angle_marker_box 
+    { \_l_siunitx_angle_marker_dim }
+    {
+      \tex_hss:D
+      \hbox_unpack_clear:N \_l_siunitx_angle_marker_box
+      \tex_hss:D
+    }
+  \box_use:N \_l_siunitx_angle_marker_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_unit: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_angle_marker_box 
+    { \_l_siunitx_angle_unit_dim } 
+    {
+      \tex_hss:D
+      \hbox_unpack_clear:N \_l_siunitx_angle_marker_box
+      \tex_hss:D
+    }
+  \box_use:N \_l_siunitx_angle_marker_box
+  \skip_horizontal:N \scriptspace
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_angle_print_direct:nnn}
+%\begin{macro}[aux]{\_siunitx_angle_print_direct_aux:nn}
+% The direct printing routine is rather similar to the standard
+% one, with just a modified final step.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_angle_print_direct:nnn #1#2#3 {
+  \_siunitx_angle_print_direct_aux:nn {#1} { \SIUnitSymbolDegree }
+  \bool_if:NT \_l_siunitx_angle_degree_space_bool
+    { 
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl } 
+    }
+  \_siunitx_angle_print_direct_aux:nn {#2} { \SIUnitSymbolArcminute }
+  \bool_if:NT \_l_siunitx_angle_minute_space_bool
+    { 
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl } 
+    }
+  \_siunitx_angle_print_direct_aux:nn {#3} { \SIUnitSymbolArcsecond }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_direct_aux:nn #1#2 {
+  \tl_if_empty:nF {#1}
+    {
+      \tl_set:Nn \_l_siunitx_unit_tl {#2}
+      \_siunitx_print:nn { number } { \_siunitx_ensuremath:n {#1} }
+      \_siunitx_unit_output_print:
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\celsius}
-%\begin{macro}{\degreeCelsius}
-%\begin{macro}{\Celsius}
-% The degree celsius is a named unit.
+% 
+%\subsection{Creating unit macros}
+%
+% Unit macros and related support are created here. To avoid cluttering
+% up the user name-space with a lot of short macro names, the standard
+% method only makes these available inside the unit-processing functions
+% (\cs{SI}, \cs{si} and the \texttt{S} column).
+% 
+%\begin{macro}{\_l_siunitx_declare_list_tl}
+% A list of all unit and related functions.
 %    \begin{macrocode}
-\ifsi@old@OHM
-  \newunit{\Celsius}{\si@sym@celsius}
-\else
-  \ifsi@gensymb\else
-    \newunit{\celsius}{\si@sym@celsius}
-  \fi
-\fi
-\newunit\degreeCelsius{\si@sym@celsius}
+\tl_new:N \_l_siunitx_declare_list_tl
+\tl_set:Nn \_l_siunitx_declare_list_tl { \of \per \raiseto \tothe }
+%    \end{macrocode}
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_declare_power_after:Nn}
+%\begin{macro}{\_siunitx_declare_power_before:Nn}
+% Creating powers is all about storing values.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_declare_power_after:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } 
+    { \textsuperscript {#2} }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w } 
+    { \_siunitx_unit_parse_power_after:n {#2} }
+}
+\cs_set_protected:Npn \_siunitx_declare_power_before:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } ##1 
+    { ##1 \textsuperscript {#2} }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w } 
+    { \_siunitx_unit_parse_power_before:n {#2} }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_declare_prefix:Nnnn}
+% Prefixes need to store both the symbol and the power they represent.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_declare_prefix:Nnnn #1#2#3#4 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } {#2}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w } 
+    {
+      \bool_if:NTF \_l_siunitx_prefix_symbols_bool 
+        { \_siunitx_unit_parse_prefix:n {#2} }
+        { \_siunitx_unit_parse_prefix:nn {#3} {#4} }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\radian}
-%\begin{macro}{\steradian}
-% The radian and steradian are officially derived units.
+%
+%\begin{macro}{\_siunitx_declare_qualifier:Nn}
+% Qualifiers just need storing.
 %    \begin{macrocode}
-\newunit{\radian}{rad}
-\newunit{\steradian}{sr}
+\cs_set_protected:Npn \_siunitx_declare_qualifier:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } 
+    { \text { ~ } ( #2 ) }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    { \_siunitx_unit_parse_qualifier:n {#2} }
+}
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\_siunitx_declare_unit:Nnn}
+%\begin{macro}[aux]{\_siunitx_unit_first_token:n}
+% Creating units requires various things to be stored.  This is done
+% with several storage bins to keep the code clear.  For the 
+% \texttt{macro} definition, the test occurs at use so that there is no
+% problem with the creation order for units.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_declare_unit:Nnn #1#2#3 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } {#2}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w } 
+    {
+      \cs_if_exist:cTF 
+        { _siunitx_ \_siunitx_unit_first_token:n {#2} _function:w }
+        {#2}
+        { \_siunitx_unit_parse_unit:Nn #1 {#2} }
+    }
+  \tl_if_empty:nTF {#3}
+    { 
+      \cs_if_free:cF { _l_siunitx_ \token_to_str:N #1 _options_tl }
+        { 
+          \cs_gundefine:c { _l_siunitx_ \token_to_str:N #1 _options_tl }
+        }
+    }
+    {
+      \cs_if_free:cT { _l_siunitx_ \token_to_str:N #1 _options_tl } 
+        { \tl_new:c { _l_siunitx_ \token_to_str:N #1 _options_tl } }
+      \tl_set:cn { _l_siunitx_ \token_to_str:N #1 _options_tl } {#3} 
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_first_token:n #1 {
+  \exp_after:wN \token_to_str:N \tl_head_i:w #1 \q_nil
+}
+%    \end{macrocode}
+%\end{macro} 
 %\end{macro}
-%\iffalse
-%</named>
-%<*prefixed>
-%\fi
-%\subsection{Units with prefixes}
-% As in \unitsdef, some commonly used prefixed units are set up.
-% This requires \file{si-prefix.cfg} and \file{si-named.cfg}.
+%
+%\begin{macro}{\per}
+% The \cs{per} function is pretty simple.
 %    \begin{macrocode}
-\ProvidesFile{si-prefixed.cfg}
-  [2010/02/22 v1.4c siunitx: SI Prefixed units]
-\requiresiconfigs{prefix,named,accepted,physical}
+\cs_set:cpn { _siunitx_ \token_to_str:N \per _literal:w } { / }
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \per _function:w } {
+  \bool_set_true:N \_l_siunitx_per_bool
+  \_siunitx_unit_parse_per:
+}
 %    \end{macrocode}
-%\begin{macro}{\picometre}
-%\begin{macro}{\nanometre}
-%\begin{macro}{\micrometre}
-%\begin{macro}{\millimetre}
-%\begin{macro}{\centimetre}
-%\begin{macro}{\decimetre}
-%\begin{macro}{\kilometre}
-% Extra distances.
+%\end{macro}
+%
+%\begin{macro}{\raiseto}
+%\begin{macro}{\tothe}
+% Generic versions of the pre-set powers.
 %    \begin{macrocode}
-\newunit{\picometre}{\pico\metre}
-\newunit{\nanometre}{\nano\metre}
-\newunit{\micrometre}{\micro\metre}
-\newunit{\millimetre}{\milli\metre}
-\newunit{\centimetre}{\centi\metre}
-\newunit{\decimetre}{\deci\metre}
-\newunit{\kilometre}{\kilo\metre}
+\cs_set:cpn { _siunitx_ \token_to_str:N \raiseto _literal:w } #1#2 {
+  #2
+  \textsuperscript {#1}
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \raiseto _function:w } 
+  #1 {
+  \_siunitx_unit_parse_power_before:n {#1}
+}
+\cs_set:cpn { _siunitx_ \token_to_str:N \tothe _literal:w } #1 {
+  \textsuperscript {#1}
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \tothe _function:w } 
+  #1 {
+  \_siunitx_unit_parse_power_after:n {#1}
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\of}
+% A flexible qualifier as well.
+%    \begin{macrocode}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \of _literal:w } #1 {
+  \text { ~ } ( #1 )
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \of _function:w } #1 {
+  \_siunitx_unit_parse_qualifier:n {#1}
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\subsection{Creating body unit macros}
+%
+% The user might have asked for the unit macros to be available in the
+% document body. If so, then these are created at the start of the 
+% document body. 
+% 
+%\begin{macro}{\_l_siunitx_create_free_bool}
+%\begin{macro}{\_l_siunitx_create_overwrite_bool}
+%\begin{macro}{\_l_siunitx_create_prespace_bool}
+%\begin{macro}{\_l_siunitx_create_optional_bool}
+%\begin{macro}{\_l_siunitx_create_xspace_bool}
+% There are a few options which control this behaviour: these are all
+% preamble-only.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  free-standing-units    .bool_set:N = \_l_siunitx_create_free_bool,
+  overwrite-functions    .bool_set:N = 
+    \_l_siunitx_create_overwrite_bool,
+  space-before-unit      .bool_set:N = \_l_siunitx_create_prespace_bool,
+  unit-optional-argument .bool_set:N = \_l_siunitx_create_optional_bool,
+  use-xspace             .bool_set:N = \_l_siunitx_create_xspace_bool
+}
+\_siunitx_option_deactivate:n {
+  free-standing-units, 
+  overwrite-functions,
+  space-before-unit,
+  unit-optional-argument,
+  use-xspace
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\femtogram}
-%\begin{macro}{\picogram}
-%\begin{macro}{\nanogram}
-%\begin{macro}{\microgram}
-%\begin{macro}{\milligram}
-% Extra masses.
+%\end{macro} 
+%
+% The master control macro which occurs at the start of the document.
+%    \begin{macrocode}
+\AtBeginDocument {
+  \bool_if:NTF \_l_siunitx_create_free_bool 
+    { \_siunitx_unit_create_functions: }
+    { \_siunitx_unit_create_empty_functions: }
+}
+%    \end{macrocode}
+%
+%\begin{macro}{\_siunitx_unit_create_empty_functions:}
+%\begin{macro}[aux]{\_siunitx_unit_create_empty_functions_aux:N}
+% Without this, horrible things happen with \pkg{memoir} and
+% \pkg{hyperref}.
 %    \begin{macrocode}
-\newunit{\femtogram}{\femto\gram}
-\newunit{\picogram}{\pico\gram}
-\newunit{\nanogram}{\nano\gram}
-\newunit{\microgram}{\micro\gram}
-\newunit{\milligram}{\milli\gram}
+\cs_set_protected_nopar:Npn \_siunitx_unit_create_empty_functions: {
+  \tl_map_function:NN \_l_siunitx_declare_list_tl 
+    \_siunitx_unit_create_empty_functions_aux:N
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_unit_create_empty_functions_aux:N #1 {
+  \cs_if_free:NT #1 { \cs_set_protected_nopar:Npn #1 { \ERROR } }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_create_functions:}
+% Creation of macros essentially involves picking up a couple of loops.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_create_functions: {
+  \bool_if:NT \_l_siunitx_create_overwrite_bool 
+    { \tl_map_function:NN \_l_siunitx_declare_list_tl \cs_gundefine:N }
+  \bool_if:NTF \_l_siunitx_create_optional_bool 
+    {
+      \tl_map_function:NN \_l_siunitx_declare_list_tl 
+        \_siunitx_unit_create_with_arg:N
+    }
+    {
+      \tl_map_function:NN \_l_siunitx_declare_list_tl 
+        \_siunitx_unit_create:N
+    }
+  \bool_if:NT \_l_siunitx_create_xspace_bool 
+    { \RequirePackage { xspace } }
+}
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_create:N}
+%\begin{macro}{\_siunitx_unit_create_with_arg:N}
+% The creation functions expand everything as far as possible so that
+% there is less to do in the document.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_create:N #1 {
+  \cs_if_free:NT #1 
+    {
+      \cs_set:Npx \_siunitx_tmp:w 
+        {
+          \ProvideDocumentCommand \exp_not:N #1 { } 
+            {
+              \bool_if:NT \_l_siunitx_create_prespace_bool 
+                {
+                  \exp_not:n 
+                    { 
+                      \_siunitx_ensuremath:n 
+                        { \_l_siunitx_number_unit_sep_tl } 
+                    }
+                }
+              \exp_not:n { \_siunitx_unit_in:nn {#1} { } }
+              \bool_if:NT \_l_siunitx_create_xspace_bool 
+                { \exp_not:N \xspace }
+            }
+        }
+      \_siunitx_tmp:w
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_create_with_arg:N #1 {
+  \cs_if_free:NT #1 
+    {
+      \cs_set:Npx \_siunitx_tmp:w 
+        {
+          \ProvideDocumentCommand \exp_not:N #1 { o } 
+            {
+              \exp_not:N \IfNoValueTF {####1} 
+                { \exp_not:n { \_siunitx_unit_in:nn {#1} { } } }
+                {
+                  \bool_if:NT \_l_siunitx_create_prespace_bool 
+                    {
+                      \exp_not:n 
+                        { 
+                          \_siunitx_ensuremath:n 
+                            { \_l_siunitx_number_unit_sep_tl }
+                        }
+                    }
+                  \SI {####1} { \exp_not:N #1 }
+                }
+              \bool_if:NT \_l_siunitx_create_xspace_bool
+                { \exp_not:N \xspace }
+            }
+        }
+      \_siunitx_tmp:w
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_protect_symbols:N}
+% There are a few unit names which may be defined by other parts of
+% LaTeX. They need to be unexpandable, as in an \texttt{s} column
+% TeX will look for \cs{omit} \emph{before} starting the internal
+% version of \cs{si} and doing a redefinition. The same is true 
+% for the \cs{color} function, which may well be the first thing in 
+% a table cell.
+%    \begin{macrocode}
+\AtBeginDocument {
+  \tl_map_function:nN { \bar \color \ng \pm } 
+    \_siunitx_protect_symbols:N
+}
+\cs_set_protected_nopar:Npn \_siunitx_protect_symbols:N #1 {
+  \cs_if_exist:NT #1 
+    {
+      \_siunitx_cs_if_macro:NT #1 
+        { \cs_set_protected_nopar:Npx #1 { \exp_not:V #1 } }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\femtomole}
-%\begin{macro}{\picomole}
-%\begin{macro}{\nanomole}
-%\begin{macro}{\micromole}
-%\begin{macro}{\millimole}
-%\begin{macro}{\kilomole}
-%\changes{v1.1e}{2008/11/18}{New unit}
-% Now some moles.
+%
+%\subsection{Initial unit processing}
+%
+% The unit processor has to convert the input (which may be all macros
+% or may contain literal input) into formatted text for output.  The 
+% input part of the process is used to sort out parsed or literal units.
+%
+%\begin{macro}{\_l_siunitx_unit_forbid_literal_bool}
+%\begin{macro}{\_l_siunitx_unit_parse_bool}
+% One option is related to how units are pre-processed.
 %    \begin{macrocode}
-\newunit{\femtomole}{\femto\mole}
-\newunit{\picomole}{\pico\mole}
-\newunit{\nanomole}{\nano\mole}
-\newunit{\micromole}{\micro\mole}
-\newunit{\millimole}{\milli\mole}
-\newunit{\kilomole}{\kilo\mole}
+\keys_define:nn { siunitx } {
+  forbid-literal-units .bool_set:N = 
+    \_l_siunitx_unit_forbid_literal_bool,
+  parse-units          .bool_set:N = \_l_siunitx_unit_parse_bool
+}
+\keys_set:nn { siunitx } {
+  forbid-literal-units = false,
+  parse-units          = true
+}
+%    \end{macrocode}
+%\end{macro} 
+%\end{macro}  
+% 
+%\begin{macro}{\_siunitx_unit_in:nn}
+%\begin{macro}{\_siunitx_unit_in:Vn}
+% The master function does a very simple checks then hands off. 
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_in:nn #1#2 {
+  \bool_if:NTF \_l_siunitx_unit_parse_bool 
+    {
+      \tl_if_empty:nF {#1} 
+        {
+          \_siunitx_unit_if_literal:nTF {#1} 
+            {
+              \bool_if:NTF \_l_siunitx_unit_forbid_literal_bool 
+                { \msg_error:nnx { siunitx } { literal-unit } {#1} }
+                { \_siunitx_unit_format_literal:n {#1} }
+            }
+            {
+              \bool_if:NT \_l_siunitx_per_auto_bool
+                {
+                  \tl_set:Nn \_l_siunitx_per_mode_tl { symbol }
+                  \mode_if_inner:F
+                    { 
+                      \mode_if_math:T 
+                        { 
+                          \tl_set:Nn \_l_siunitx_per_mode_tl 
+                            { fraction }
+                        }
+                    }
+                }
+              \_siunitx_unit_parse:nn {#1} {#2}
+              \_siunitx_unit_format:            
+            }
+      }
+  }
+  { \_siunitx_unit_format_literal:n {#1} }
+}
+\cs_generate_variant:Nn \_siunitx_unit_in:nn { Vn }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_if_literal:nTF}
+%\begin{macro}[aux]{\_siunitx_unit_if_literal_aux:N}
+% A test is needed to see if the input only contains unit macros. This 
+% is done by altering setting all of the unit macros to expand to 
+% nothing at all. Thus there will only be anything left if there is
+% a literal in the unit.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_if_literal:nTF #1#2#3 {
+  \group_begin:
+    \tl_map_function:NN \_l_siunitx_declare_list_tl
+      \_siunitx_unit_if_literal_aux:N
+    \cs_set_eq:NN \of \use_none:n  
+    \cs_set_eq:NN \raiseto \use_none:n
+    \cs_set_eq:NN \tothe \use_none:n
+    \protected@edef \_l_siunitx_tmpa_tl {#1}
+  \exp_args:NNNV \group_end:
+  \tl_set:Nn \_l_siunitx_tmpa_tl \_l_siunitx_tmpa_tl
+  \tl_if_empty:NTF \_l_siunitx_tmpa_tl {#3} {#2}
+}
+\cs_set_protected:Npn \_siunitx_unit_if_literal_aux:N #1 {
+  \cs_set_eq:NN #1 \prg_do_nothing:
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Parsing macro units}
+%
+% For macro-based units, the macros are converted into literal text,
+% which is then passed on for printing. The code reads through the 
+% input to collect up the units, before re-combining everything into
+% a single block at the end of the process.
+%
+%\begin{macro}{\_l_siunitx_unit_int}
+%\begin{macro}{\_l_siunitx_unit_prop}
+% Parsed units are stored in a property list, to keep things compact.
+% An integer is also needed to count up units.
+%    \begin{macrocode}
+\int_new:N \_l_siunitx_unit_int
+\prop_new:N \_l_siunitx_unit_prop
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\attosecond}
-%\begin{macro}{\femtosecond}
-%\begin{macro}{\picosecond}
-%\begin{macro}{\nanosecond}
-%\begin{macro}{\microsecond}
-%\begin{macro}{\millisecond}
-% Prefixed seconds.
+%
+%\begin{macro}{\_l_siunitx_per_bool}
+% To allow \cs{per} to be \enquote{sticky}.
 %    \begin{macrocode}
-\newunit{\attosecond}{\atto\second}
-\newunit{\femtosecond}{\femto\second}
-\newunit{\picosecond}{\pico\second}
-\newunit{\nanosecond}{\nano\second}
-\newunit{\microsecond}{\micro\second}
-\newunit{\millisecond}{\milli\second}
+\bool_new:N \_l_siunitx_per_bool
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_prefix_symbols_bool}
+%\begin{macro}{\_l_siunitx_sticky_per_bool}
+% Some options are directly related to how units are handled at this
+% stage, so need be created before the reconstruction part of the code.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  prefixes-as-symbols .bool_set:N    = \_l_siunitx_prefix_symbols_bool,
+  sticky-per          .bool_set:N    = \_l_siunitx_sticky_per_bool,
+}
+\keys_set:nn { siunitx } {
+  prefixes-as-symbols = true
+}
+%    \end{macrocode} 
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_unit_parse:nn}
+% The unit to be parsed is received here along with any options given.
+% The later are needed so that the user can override any saved options
+% on a one-off basis.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_parse:nn #1#2 {
+  \_siunitx_unit_parse_init:
+  \_siunitx_unit_parse_options:nn {#1} {#2}
+  #1
+  \cs_set_eq:NN \pm \_siunitx_pm:
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_parse_init:}
+%\begin{macro}[aux]{\_siunitx_unit_parse_init_aux:N}
+%\begin{macro}{\_siunitx_pm:}
+% As always, the initialisation is a separate routine to make life a
+% little clearer. The definition of \cs{pm} is saved here as it
+% is used by units and numbers.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_init: {
+  \prop_clear:N \_l_siunitx_unit_prop
+  \int_zero:N \_l_siunitx_unit_int
+  \bool_set_false:N \_l_siunitx_per_bool
+  \cs_set_eq:NN \_siunitx_pm: \pm
+  \tl_map_function:NN \_l_siunitx_declare_list_tl 
+    \_siunitx_unit_parse_init_aux:N
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_init_aux:N #1 {
+  \cs_set_eq:Nc #1 { _siunitx_ \token_to_str:N #1 _function:w }
+}
+\cs_set_protected_nopar:Npn \_siunitx_pm: { }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_parse_options:n}
+% Any unit-specific options are loaded, followed by re-applying any
+% options given for this particular macro. The second call to 
+% \cs{keys_set:nn}  is needed to allow the local overriding of settings.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_parse_options:nn #1#2 {
+  \cs_if_free:cF 
+    { _l_siunitx_ \_siunitx_unit_first_token:n {#1} _options_tl }
+    {
+      \keys_set:nv { siunitx } 
+        { _l_siunitx_ \_siunitx_unit_first_token:n {#1} _options_tl }
+      \keys_set:nn { siunitx } {#2}
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\picoampere}
-%\begin{macro}{\nanoampere}
-%\begin{macro}{\microampere}
-%\begin{macro}{\milliampere}
-%\begin{macro}{\kiloampere}
-% The last prefixed base units are amperes.
+%
+%\begin{macro}{\_siunitx_unit_parse_power_before:n}
+%\begin{macro}{\_siunitx_unit_parse_power_after:n}
+% Storing powers depends on whether they are given before or after
+% the unit.
 %    \begin{macrocode}
-\newunit{\picoampere}{\pico\ampere}
-\newunit{\nanoampere}{\nano\ampere}
-\newunit{\microampere}{\micro\ampere}
-\newunit{\milliampere}{\milli\ampere}
-\newunit{\kiloampere}{\kilo\ampere}
+\cs_set_protected:Npn \_siunitx_unit_parse_power_before:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { power- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_power_after:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_parse_prefix:n}
+%\begin{macro}{\_siunitx_unit_parse_prefix:nn}
+% Saving prefixes always increments the counter. For non-symbolic 
+% mode, the base needs to be saved along with the power.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_parse_prefix:n #1 {
+  \int_incr:N \_l_siunitx_unit_int
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_prefix:nn #1#2 {
+  \_siunitx_unit_parse_prefix:n {#2}
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { prefix-base- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_parse_per:}
+% The \cs{per} function always applies to the next unit seen, so
+% the counter has to be advanced by one.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_per: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    {  per- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl { true }
+  \bool_if:NT \_l_siunitx_sticky_per_bool
+    { \cs_set_eq:NN \per \_siunitx_unit_parse_per_error: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_per_error: {
+  \msg_error:nn { siunitx } { duplicate-sticky-per }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\millivolt}
-%\begin{macro}{\kilovolt}
-%\begin{macro}{\milliwatt}
-%\begin{macro}{\kilowatt}
-%\begin{macro}{\megawatt}
-%\begin{macro}{\femtofarad}
-%\begin{macro}{\picofarad}
-%\begin{macro}{\nanofarad}
-%\begin{macro}{\microfarad}
-%\begin{macro}{\millifarad}
-%\begin{macro}{\millisiemens}
-% More electricity-related units.
+%
+%\begin{macro}{\_siunitx_unit_parse_qualifier:n}
+% Qualifiers never alter the number of units.
 %    \begin{macrocode}
-\newunit{\millivolt}{\milli\volt}
-\newunit{\kilovolt}{\kilo\volt}
-\newunit{\milliwatt}{\milli\watt}
-\newunit{\kilowatt}{\kilo\watt}
-\newunit{\megawatt}{\mega\watt}
-\newunit{\femtofarad}{\femto\farad}
-\newunit{\picofarad}{\pico\farad}
-\newunit{\nanofarad}{\nano\farad}
-\newunit{\microfarad}{\micro\farad}
-\newunit{\millifarad}{\milli\farad}
-\newunit{\millisiemens}{\milli\siemens}
+\cs_set_protected:Npn \_siunitx_unit_parse_qualifier:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    { \msg_error:nn { siunitx } { qualifier-before-unit } }
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { qualifier- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_parse_unit:Nn}
+%\begin{macro}[aux]{\_siunitx_unit_parse_unit_per:}
+% For units, there is a check in case a prefix is present (which will 
+% have incremented the counter). With the counter correct, simply add
+% the literal to the property list. There is also a check to see if
+% there is a \enquote{sticky} \cs{per} to think about.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_parse_unit:Nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl 
+        { symbol- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+        { \int_incr:N \_l_siunitx_unit_int }
+    }
+    { \int_incr:N \_l_siunitx_unit_int }
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { unit- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#2}
+  \_siunitx_unit_parse_unit_per: 
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_unit_per: {
+  \bool_if:NT \_l_siunitx_sticky_per_bool 
+    {
+      \bool_if:NT \_l_siunitx_per_bool 
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl 
+            { per- \int_use:N \_l_siunitx_unit_int }
+          \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+            { true }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Unit formatting}
+%
+%\begin{macro}{\_l_siunitx_preunit_tl}
+%\begin{macro}{\_l_siunitx_unit_tl}
+%\begin{macro}{\_l_siunitx_unit_current_tl}
+%\begin{macro}{\_l_siunitx_unit_denominator_tl}
+%\begin{macro}{\_l_siunitx_unit_numerator_tl}
+%\begin{macro}{\_l_siunitx_unit_saved_tl}
+% Storage space for creating unit output.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_preunit_tl
+\tl_new:N \_l_siunitx_unit_tl
+\tl_new:N \_l_siunitx_unit_current_tl
+\tl_new:N \_l_siunitx_unit_denominator_tl
+\tl_new:N \_l_siunitx_unit_numerator_tl
+\tl_new:N \_l_siunitx_unit_saved_tl
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_unit_denominator_int}
+%\begin{macro}{\_l_siunitx_unit_numerator_int}
+% For tracking in case brackets are needed.
+%    \begin{macrocode}
+\int_new:N \_l_siunitx_unit_denominator_int
+\int_new:N \_l_siunitx_unit_numerator_int
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\kilohm}
-%\changes{v1.1f}{2008/11/25}{Renamed from \cs{kiloohm}}
-%\begin{macro}{\megohm}
-%\changes{v1.1f}{2008/11/25}{Renamed from \cs{megaohm}}
-%\begin{macro}{\gigaohm}
-% For resistance, checks are needed again for the definition of
-% \cs{ohm}.
+%
+%\begin{macro}{\_l_siunitx_unit_prefix_int}
+%\begin{macro}{\_l_siunitx_unit_prefix_base_int}
+%\begin{macro}{\_l_siunitx_unit_prefix_current_tl}
+% Used to calculate the overall prefix value.
 %    \begin{macrocode}
-\ifsi@old@OHM
-  \newunit{\kilohm}{\kilo\Ohm}
-  \newunit{\megohm}{\mega\Ohm}
-  \newunit{\gigaohm}{\giga\Ohm}
-\else
-  \ifsi@gensymb\else
-  \newunit{\kilohm}{\kilo\ohm}
-  \newunit{\megohm}{\mega\ohm}
-  \newunit{\gigaohm}{\giga\ohm}
-  \fi
-\fi
+\int_new:N \_l_siunitx_unit_prefix_int
+\int_new:N \_l_siunitx_unit_prefix_base_int
+\tl_new:N \_l_siunitx_unit_prefix_current_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\microlitre}
-%\begin{macro}{\millilitre}
-%\begin{macro}{\microliter}
-%\begin{macro}{\milliliter}
-%\begin{macro}{\cubicmetre}
-%\begin{macro}{\cubiccentimetre}
-%\begin{macro}{\centimetrecubed}
-%\begin{macro}{\cubicmicrometre}
-%\begin{macro}{\cubicmillimetre}
-%\begin{macro}{\cubicdecimetre}
-% Volumes (unlike \unitsdef, with litre and metre spelled
-% correctly).  \cs{millilitre} and \cs{microlitre} are defined
-% as they are the two officially-sanctioned prefixes for the litre.
+%
+%\begin{macro}{\_l_siunitx_unit_prefix_gram_int}
+% Formatting units is complicated by the fact that the kilogram is a 
+% base unit, making conversions a little more awkward.
 %    \begin{macrocode}
-\newunit{\microlitre}{\micro\litre}
-\newunit{\millilitre}{\milli\litre}
-\newunit{\microliter}{\micro\liter}
-\newunit{\milliliter}{\milli\liter}
-\newunit{\cubicmetre}{\metre\cubed}
-\newunit{\cubiccentimetre}{\centi\metre\cubed}
-\newunit{\centimetrecubed}{\centi\metre\cubed}
-\newunit{\cubicmicrometre}{\micro\metre\cubed}
-\newunit{\cubicmillimetre}{\milli\metre\cubed}
-\newunit{\cubicdecimetre}{\cubic\deci\metre}
+\int_new:N \_l_siunitx_unit_prefix_gram_int
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_per_auto_bool}
+%\begin{macro}{\_l_siunitx_per_fraction_bool}
+%\begin{macro}{\_l_siunitx_per_mode_tl}
+%\begin{macro}{\_l_siunitx_qualifier_mode_tl}
+%\begin{macro}{\_l_siunitx_per_two_parts_bool}
+% For saving settings.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_per_auto_bool
+\bool_new:N \_l_siunitx_per_fraction_bool
+\tl_new:N \_l_siunitx_per_mode_tl
+\bool_new:N \_l_siunitx_two_parts_bool
+\tl_new:N \_l_siunitx_qualifier_mode_tl
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_unit_denominator_bracket_bool}
+%\begin{macro}{\_l_siunitx_unit_separator_tl}
+%\begin{macro}{\_l_siunitx_per_symbol_tl}
+% At this stage, output formatting options are created.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  bracket-unit-denominator .bool_set:N 
+    = \_l_siunitx_unit_denominator_bracket_bool,
+  inter-unit-separator .tl_set:N = \_l_siunitx_unit_separator_tl ,
+  per-mode             .choice:,
+  per-mode / fraction .code:n = 
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { fraction }
+    },
+  per-mode / power      .meta:n = { per-mode = reciprocal } ,
+  per-mode / power-positive-first .meta:n = 
+    { per-mode = reciprocal-positive-first } ,
+  per-mode / reciprocal .code:n = 
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_false:N \_l_siunitx_per_two_parts_bool
+      \tl_clear:N \_l_siunitx_per_mode_tl 
+    },
+  per-mode / reciprocal-positive-first .code:n = 
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_clear:N \_l_siunitx_per_mode_tl 
+    },
+  per-mode / repeated-symbol .code:n = 
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_false:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { repeat }
+    },
+  per-mode / symbol .code:n = 
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { symbol }
+    },
+  per-mode / symbol-or-fraction .code:n = 
+    {
+      \bool_set_true:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+    },
+  per-symbol           .tl_set:N  = \_l_siunitx_per_symbol_tl,
+  qualifier-mode       .choice:,
+  qualifier-mode / brackets .code:n = 
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { brackets } },
+  qualifier-mode / space .code:n = 
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { space } },
+  qualifier-mode / subscript .code:n = 
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { subscript } },
+}
+\keys_set:nn { siunitx } {
+  bracket-unit-denominator = true,
+  inter-unit-separator     = \,,
+  per-mode                 = reciprocal,
+  per-symbol               = /,
+  qualifier-mode           = subscript
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format:}
+% Most of the work is done by the loop, with a little tidying up for
+% fraction-like output. Before starting the loop, there is a check for
+% the case of a single reciprocal unit when per is set up to create a
+% symbol. In that special case, the space between a number and a unit 
+% has to be removed.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format: {
+  \_siunitx_unit_format_init:
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_unit_int } = { 1 } 
+    { 
+      \tl_if_eq:VnT \_l_siunitx_per_mode_tl { symbol }
+        {
+          \prop_if_in:NnT \_l_siunitx_unit_prop { per-1 }
+            { \tl_clear:N \_l_siunitx_number_unit_separator_tl }
+        }
+    }
+  \intexpr_while_do:nNnn 
+    { \int_use:N \_l_siunitx_unit_int } > { 0 }
+    {
+      \_siunitx_unit_format_prefix:
+      \_siunitx_unit_format_symbol:
+      \_siunitx_unit_format_qualifier:
+      \_siunitx_unit_format_power:
+      \_siunitx_unit_format_add:
+      \int_decr:N \_l_siunitx_unit_int
+    }  
+  \bool_if:NT \_l_siunitx_per_two_parts_bool 
+    {
+      \bool_if:NTF \_l_siunitx_per_fraction_bool
+        { \_siunitx_unit_format_fraction: }
+        { \_siunitx_unit_format_sorted: }
+    }
+} 
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_add:}
+%\begin{macro}[aux]{\_siunitx_unit_format_add_aux:n}
+% Adding the current unit to the output means checking where it goes.
+% The odd code when adding a space is to pick up repeated per symbols, 
+% which need to suppress the space.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_add: {
+  \bool_if:NTF \_l_siunitx_per_two_parts_bool 
+    {
+      \tl_set:Nx \_l_siunitx_tmpb_tl 
+        { per- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl 
+        {
+          \_siunitx_unit_format_add_aux:n { _denominator }
+          \int_incr:N \_l_siunitx_unit_denominator_int
+        }
+        {
+          \_siunitx_unit_format_add_aux:n { _numerator }
+          \int_incr:N \_l_siunitx_unit_numerator_int
+        }
+    }
+    { \_siunitx_unit_format_add_aux:n { } }
+  \tl_clear:N \_l_siunitx_unit_current_tl
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_add_aux:n #1 {
+  \tl_if_empty:cF { _l_siunitx_unit #1 _tl } 
+    {
+      \tl_if_eq:nVTF { repeat } \_l_siunitx_per_mode_tl 
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl 
+            { per- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+          \prop_if_in:NVF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+            {
+              \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+                \_l_siunitx_unit_separator_tl
+            }
+        }
+        {  
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+            \_l_siunitx_unit_separator_tl
+        }
+    }
+  \tl_put_left:cV { _l_siunitx_unit #1 _tl } \_l_siunitx_unit_current_tl
+} 
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\squaremetre}
-%\begin{macro}{\squarecentimetre}
-%\begin{macro}{\centimetresquared}
-%\begin{macro}{\squarekilometre}
-% Areas, with metre spelled corrected; \cs{are} and \cs{hectare} are
-% in the ``temporarily accepted'' file.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_fraction:}
+%\begin{macro}[aux]{\_siunitx_unit_format_fraction:}
+%\begin{macro}[aux]{\_siunitx_unit_format_symbol:}
+%\begin{macro}[aux]{\_siunitx_unit_format_symbol_aux:}
+%\begin{macro}[aux]{\_siunitx_unit_format_symbol_aux_alt:}
+% When making (\emph{psuedo}-)fractions there is a check to place a
+% \( 1 \) in the numerator is it's blank. For symbol mode, this is
+% only done if there is no number. Then some construction work.
 %    \begin{macrocode}
-\newunit{\squaremetre}{\Square\metre}
-\newunit{\squarecentimetre}{\Square\centi\metre}
-\newunit{\centimetresquared}{\centi\metre\squared}
-\newunit{\squarekilometre}{\Square\kilo\metre}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction: {
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_unit_denominator_int } > { 0 } 
+    {
+      \use:c 
+        { _siunitx_unit_format_fraction_ \_l_siunitx_per_mode_tl : }
+    }
+    { \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl }
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_fraction: {
+  \tl_if_empty:NT \_l_siunitx_unit_numerator_tl 
+    { \tl_set:Nn \_l_siunitx_unit_numerator_tl { 1 } }
+  \tl_set:Nx \_l_siunitx_unit_numerator_tl 
+    { { \exp_not:V \_l_siunitx_unit_numerator_tl } }
+  \tl_put_left:Nn \_l_siunitx_unit_numerator_tl 
+    { \_siunitx_print:nn { unit } }   
+  \tl_set:Nx \_l_siunitx_unit_numerator_tl 
+    { { \exp_not:V \_l_siunitx_unit_numerator_tl } }
+  \tl_set:Nx \_l_siunitx_unit_denominator_tl 
+    { { \exp_not:V \_l_siunitx_unit_denominator_tl } }
+  \tl_put_left:Nn \_l_siunitx_unit_denominator_tl 
+    { \_siunitx_print:nn { unit } }   
+  \tl_set:Nx \_l_siunitx_unit_denominator_tl 
+    { { \exp_not:V \_l_siunitx_unit_denominator_tl } }
+  \tl_set:Nn \_l_siunitx_unit_tl { \_siunitx_fraction:nn }
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+  \tl_set:Nx \_l_siunitx_unit_tl 
+    { \exp_not:N \ensuremath { \exp_not:V \_l_siunitx_unit_tl } }
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_symbol: {
+  \_siunitx_unit_format_fraction_symbol_aux:
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_unit_denominator_int } > { 1 }
+    {
+      \bool_if:NT \_l_siunitx_unit_denominator_bracket_bool 
+        {
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_denominator_tl
+            \_l_siunitx_bracket_open_tl
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_denominator_tl
+            \_l_siunitx_bracket_close_tl
+        }
+    }
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_tl
+    \_l_siunitx_per_symbol_tl
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_symbol_aux: {
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_unit_format_fraction_symbol_aux_alt: {
+  \tl_if_empty:NT \_l_siunitx_unit_numerator_tl 
+    { \tl_set:Nn \_l_siunitx_unit_numerator_tl { 1 } }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\millijoule}
-%\begin{macro}{\kilojoule}
-%\begin{macro}{\megajoule}
-%\begin{macro}{\millielectronvolt}
-%\begin{macro}{\kiloelectronvolt}
-%\begin{macro}{\megaelectronvolt}
-%\begin{macro}{\gigaelectronvolt}
-%\begin{macro}{\teraelectronvolt}
-%\begin{macro}{\kilowatthour}
-% Some energy is needed by now!  Notice the definition of
-% \cs{kilowatthour}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_init:}
+% The normal initialisation stuff.
 %    \begin{macrocode}
-\newunit{\millijoule}{\milli\joule}
-\newunit{\kilojoule}{\kilo\joule}
-\newunit{\megajoule}{\mega\joule}
-\newunit{\millielectronvolt}{\milli\electronvolt}
-\newunit{\kiloelectronvolt}{\kilo\electronvolt}
-\newunit{\megaelectronvolt}{\mega\electronvolt}
-\newunit{\gigaelectronvolt}{\giga\electronvolt}
-\newunit{\teraelectronvolt}{\tera\electronvolt}
-\newunit[unitsep=none]{\kilowatthour}{\kilo\watt\hour}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_init: {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_unit_current_tl
+  \tl_clear:N \_l_siunitx_unit_denominator_tl
+  \int_zero:N \_l_siunitx_unit_prefix_gram_int
+  \tl_clear:N \_l_siunitx_unit_numerator_tl
+  \int_zero:N \_l_siunitx_unit_prefix_base_int
+  \int_zero:N \_l_siunitx_unit_prefix_int
+  \int_zero:N \_l_siunitx_unit_denominator_int
+  \int_zero:N \_l_siunitx_unit_numerator_int
+} 
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_literal:n}
+%\begin{macro}{\_siunitx_unit_format_literal_aux:N}
+% If the unit given contains anything which is not a unit macro, then
+% any unit macros that are there simply dump literal meanings. There is 
+% then a little work to do sorting out "~" and \texttt{.} characters at 
+% the outer level. 
+%    \begin{macrocode}
+\char_make_active:N \~
+\cs_set_protected:Npn \_siunitx_unit_format_literal:n #1 {
+  \int_zero:N \_l_siunitx_unit_prefix_int
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_print_literal_aux:N
+  \tl_set:Nn \_l_siunitx_unit_tl {#1}
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    {
+      \exp_not:N \_siunitx_ensuremath:n
+        { \exp_not:V \_l_siunitx_unit_separator_tl }
+    }
+  \tl_replace_all_in:NnV \_l_siunitx_unit_tl { . } 
+    \_l_siunitx_tmpa_tl
+  \tl_replace_all_in:NnV \_l_siunitx_unit_tl { ~ } 
+    \_l_siunitx_tmpa_tl
+  \_siunitx_unit_format_literal_extras:  
+}
+\cs_set_protected:Npn \_siunitx_unit_print_literal_aux:N #1 {
+  \cs_set_eq:Nc #1 { _siunitx_ \token_to_str:N #1 _literal:w }
+}  
+\char_make_space:N \~
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_literal_extras:}
+%\begin{macro}[aux]{\_siunitx_unit_format_literal_extras_aux:nN}
+% The code here deals with characters outside the normal range that 
+% can appear in units in UTF-8 and related encodings. The idea is to
+% do a search and replace, thus avoiding any active characters.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_literal_extras: { 
+  \_siunitx_unit_format_literal_extras_aux:nN { 176 }
+    \SIUnitSymbolDegree
+  \_siunitx_unit_format_literal_extras_aux:nN { 181 }
+    \SIUnitSymbolMicro
+  \_siunitx_unit_format_literal_extras_aux:nN { 197 }
+    \SIUnitSymbolAngstrom 
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_unit_format_literal_extras_aux:nN #1#2 {
+  \char_set_lccode:nn { `\@ } {#1}
+  \tl_to_lowercase:n
+    { 
+      \tl_replace_all_in:NnV \_l_siunitx_unit_tl { @ } 
+        \_l_siunitx_unit_tl
+    }
+}
+\xetex_if_engine:F {
+    \AtBeginDocument 
+      {
+        \@ifpackageloaded { inputenc }
+          {
+            \tl_set:Nn \_l_siunitx_tmpa_tl { latin1 , latin5 , latin9 }
+            \clist_if_in:NVF \_l_siunitx_tmpa_tl \inputencodingname 
+              { 
+                \cs_set_eq:NN \_siunitx_unit_format_literal_extras: 
+                  \scan_stop:
+              }
+          }
+          { 
+            \cs_set_eq:NN \_siunitx_unit_format_literal_extras:
+              \scan_stop: 
+          }
+      }  
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_power:}
+% To format powers, there are a few issues: are brackets needed, is
+% the power reciprocal and is fraction-formatting in operation. Repeated
+% per symbols make life a little more complex, as they have to be 
+% handled here as well. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl  
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl 
+        { per- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+        {
+          \tl_set:Nn \_l_siunitx_tmpa_tl { 1 }
+          \_siunitx_unit_format_power_aux:
+        }
+    }
+    { \_siunitx_unit_format_power_aux: }
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}[aux]{\_siunitx_unit_format_power_aux:}
+%\begin{macro}[aux]{\_siunitx_unit_format_power_aux:n}
+% The auxiliary function needs to make sure that the printing routine
+% prints the power as a number, not as text: the two modes may be
+% different. A search and replace function is needed for superscripts
+% in text mode so that negative signs get printed correctly.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_aux: {
+  \tl_if_eq:nVTF { repeat } \_l_siunitx_per_mode_tl 
+    { \_siunitx_unit_format_power_repeat: }
+    { \_siunitx_unit_format_power_per: }
+  \tl_if_eq:nVF { 1 } \_l_siunitx_tmpa_tl 
+    {
+      \_siunitx_unit_format_power_brackets:
+      \tl_put_right:Nx \_l_siunitx_unit_current_tl 
+        { 
+          ^ 
+            { 
+              \_siunitx_unit_format_power_aux:n 
+                { \exp_not:V \_l_siunitx_tmpa_tl } 
+            } 
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_format_power_aux:n #1 {
+  \bool_if:NTF \_l_siunitx_number_math_mode_bool
+    { \_siunitx_print:nn { number } {#1} }
+    {
+      \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+      \tl_replace_all_in:Nnn \_l_siunitx_tmpa_tl { - } 
+        { \text { \_c_siunitx_minus_tl } }
+    \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+   }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\millihertz}
-%\begin{macro}{\kilohertz}
-%\begin{macro}{\megahertz}
-%\begin{macro}{\gigahertz}
-%\begin{macro}{\terahertz}
-% Frequencies.
+%\begin{macro}[aux]{\_siunitx_unit_format_power_brackets:}
+% A check is made for a qualifier with a space, which needs brackets
+% if there is also a power.
 %    \begin{macrocode}
-\newunit{\millihertz}{\milli\hertz}
-\newunit{\kilohertz}{\kilo\hertz}
-\newunit{\megahertz}{\mega\hertz}
-\newunit{\gigahertz}{\giga\hertz}
-\newunit{\terahertz}{\tera\hertz}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_brackets: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl 
+    { bracket- \int_use:N \_l_siunitx_unit_int }  
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl 
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_current_tl 
+        \_l_siunitx_bracket_open_tl
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+        \_l_siunitx_bracket_close_tl
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}[aux]{\_siunitx_unit_format_power_per:}
+%\begin{macro}[aux]{\_siunitx_unit_format_power_repeat:}
+% For dealing with \cs{per} and repeated \cs{per} symbols. The sign
+% change does not use any numbers, as this makes life easier with 
+% non-integer values.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_per: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl 
+    { per- \int_use:N \_l_siunitx_unit_int }  
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl 
+    {
+      \bool_if:NF \_l_siunitx_per_fraction_bool 
+        {
+          \tl_if_in:NnTF \_l_siunitx_tmpa_tl { - } 
+            {
+              \cs_set:Npn \_siunitx_tmp:w ##1 - ##2 \q_stop 
+                { \tl_set:Nn \_l_siunitx_tmpa_tl {##2} }
+              \exp_afer:wN \_siunitx_tmp:w \_l_siunitx_tmpa_tl \q_stop
+            }
+            { \tl_put_left:Nn \_l_siunitx_tmpa_tl { - } }
+        }
+    } 
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_repeat: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl 
+    { per- \int_use:N \_l_siunitx_unit_int }  
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl 
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_current_tl 
+        \_l_siunitx_per_symbol_tl
+    }   
+}
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_prefix:}
+%\begin{macro}[aux]{\_siunitx_unit_format_prefix_number:}
+%\begin{macro}[aux]{\_siunitx_unit_format_prefix_number_calc:}
+%\begin{macro}[aux]{\_siunitx_unit_format_prefix_symbol:}
+% If there is a prefix, it is added to the output. When using numerical
+% output, some conversion is needed instead.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    {
+      \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+        \_l_siunitx_unit_prefix_current_tl
+      \bool_if:NTF \_l_siunitx_prefix_symbols_bool 
+        { \_siunitx_unit_format_prefix_symbol: }
+        { \_siunitx_unit_format_prefix_number: }
+    }
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_number: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { prefix-base- \int_use:N \_l_siunitx_unit_int }
+ \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+   \_l_siunitx_tmpa_tl
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_unit_prefix_base_int } = { 0 } 
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_base_int 
+        { \_l_siunitx_tmpa_tl }
+    }
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_unit_prefix_base_int } 
+      = { \_l_siunitx_tmpa_tl }
+    { \_siunitx_unit_format_prefix_number_calc: }
+    { \msg_error:nn { siunitx } { prefix-base-mismatch } }
+}
+%    \end{macrocode}
+%  The calculation for converting a unit prefix into a number is 
+%  simple unless there are grammes involved. In that case, the base unit
+%  is the kilogram and so there is some code to convert the number
+%  back correctly.  
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_number_calc: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl 
+    { \tl_set:Nn \_l_siunitx_tmpa_tl { 1 } }
+  \tl_set:Nx \_l_siunitx_tmpb_tl 
+    { unit- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+    \_l_siunitx_tmpb_tl
+  \tl_if_eq:nVT { \gram } \_l_siunitx_tmpb_tl
+    { 
+      \tl_set:Nx \_l_siunitx_unit_prefix_current_tl
+        { \intexpr_eval:n { \_l_siunitx_unit_prefix_current_tl  - 3 } } 
+      \tl_set:Nx \_l_siunitx_tmpb_tl 
+        { symbol- \int_use:N \_l_siunitx_unit_int }
+      \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl { kg }
+    }
+  \tl_set:Nx \_l_siunitx_unit_prefix_current_tl 
+    {
+       \intexpr_eval:n 
+         { \_l_siunitx_unit_prefix_current_tl * \_l_siunitx_tmpa_tl }
+    }
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { per- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_int 
+        {
+          \int_use:N \_l_siunitx_unit_prefix_int 
+            - \_l_siunitx_unit_prefix_current_tl
+        } 
+    }
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_int 
+        {
+          \int_use:N \_l_siunitx_unit_prefix_int 
+            + \_l_siunitx_unit_prefix_current_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_symbol: {
+  \tl_set_eq:NN \_l_siunitx_unit_current_tl 
+    \_l_siunitx_unit_prefix_current_tl
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\millinewton}
-%\begin{macro}{\kilonewton}
-%\begin{macro}{\hectopascal}
-%\begin{macro}{\megabecquerel}
-%\begin{macro}{\millisievert}
-% A few more from various areas.
+%
+%\begin{macro}{\_siunitx_unit_format_qualifier:}
+%\begin{macro}{\_siunitx_unit_format_qualifier_brackets:}
+%\begin{macro}{\_siunitx_unit_format_qualifier_space:}
+%\begin{macro}{\_siunitx_unit_format_qualifier_subscript:}
+% Three methods for showing qualifiers, each with its own sub-function.
+% For the \texttt{space} methods, a warning is set in the property list
+% as if there is a power then some brackets will be needed.
 %    \begin{macrocode}
-\newunit{\millinewton}{\milli\newton}
-\newunit{\kilonewton}{\kilo\newton}
-\newunit{\hectopascal}{\hecto\pascal}
-\newunit{\megabecquerel}{\mega\becquerel}
-\newunit{\millisievert}{\milli\sievert}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { qualifier- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \use:c 
+        { 
+          _siunitx_unit_format_qualifier_ 
+          \_l_siunitx_qualifier_mode_tl :
+        }
+    }
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_brackets: {
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+    \_l_siunitx_bracket_open_tl
+  \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+    \_l_siunitx_bracket_close_tl
+}
+\char_make_active:N \~
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_space: {
+  \tl_put_right:Nn \_l_siunitx_unit_current_tl { \text { ~ } }
+  \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { bracket- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl { true }
+}
+\char_make_space:N \~
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_subscript: 
+    {
+      \tl_put_right:No \_l_siunitx_unit_current_tl 
+        { \exp_after:wN @ \exp_after:wN { \_l_siunitx_tmpa_tl } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_format_sorted:}
+% For when the powers are sorted with the positive ones first. The only
+% slight issue is making sure that the additional space is included
+% between the two units, if needed.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_sorted: {
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \tl_if_empty:NF \_l_siunitx_unit_tl
+    {
+      \tl_if_empty:NF \_l_siunitx_unit_denominator_tl
+        { 
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_tl
+            \_l_siunitx_unit_separator_tl
+        }
+    }
+    \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+}
+%    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</prefixed>
-%<*abbr>
-%\fi
-%\subsection{Abbreviated units}
-%\begin{macro}{\pA}
-%\begin{macro}{\nA}
-%\begin{macro}{\micA}
-%\begin{macro}{\mA}
-%\begin{macro}{\kA}
-% The abbreviated units are sorted in one file.  To allow
-% back-compatibility with \unitsdef, each one is inside an \cs{if}
-% block for the appropriate option.  First currents.
+%
+%\begin{macro}{\_siunitx_unit_format_symbol:}
+%\begin{macro}[aux]{\_siunitx_unit_format_symbol_aux:}
+%\begin{macro}[aux]{\_siunitx_unit_format_symbol_aux_alt:}
+% If there is no symbol, something is wrong! The only exception is
+% when the code is inside the \cs{si} function (or similar) and there
+% is only a prefix with nothing else present at all.
 %    \begin{macrocode}
-\ProvidesFile{si-abbr.cfg}
-  [2010/02/22 v1.4c siunitx: Abbreviated units]
-\requiresiconfigs{prefix,named,accepted,physical}
-\newunit{\pA}{\pico\ampere}
-\newunit{\nA}{\nano\ampere}
-\newunit{\micA}{\micro\ampere}
-\newunit{\mA}{\milli\ampere}
-\newunit{\kA}{\kilo\ampere}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl 
+    \_l_siunitx_tmpa_tl 
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl  
+    { \_siunitx_unit_format_symbol_aux: }
+    {
+      \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+    }
+} 
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol_aux: {
+  \msg_error:nn { siunitx } { prefix-only }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol_aux_alt: {
+  \intexpr_compare:nNnTF 
+    { \int_use:N \_l_siunitx_unit_int } = { 1 }
+    { 
+      \prop_del:Nn \_l_siunitx_unit_prop { prefix-1 }
+      \prop_if_empty:NF \_l_siunitx_unit_prop
+        { \msg_error:nn { siunitx } { prefix-only } } 
+    }
+    { \msg_error:nn { siunitx } { prefix-only } }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Unit output}
+% 
+% A collection of the internal parts of various user functions.
+%
+%\begin{macro}{\_l_siunitx_multi_brackets_bool}
+%\begin{macro}{\_l_siunitx_multi_repeat_bool}
+% Flags for multi-part numbers.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_multi_brackets_bool
+\bool_new:N \_l_siunitx_multi_repeat_bool
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\Hz}
-%\begin{macro}{\mHz}
-%\begin{macro}{\kHz}
-%\begin{macro}{\MHz}
-%\begin{macro}{\GHz}
-%\begin{macro}{\THz}
-% Then frequencies.
+% 
+%\begin{macro}{\_l_siunitx_product_brackets_bool}
+%\begin{macro}{\_l_siunitx_product_power_bool}
+%\begin{macro}{\_l_siunitx_number_unit_repeat_bool}
+% Flags for product units.
 %    \begin{macrocode}
-\newunit{\Hz}{\hertz}
-\newunit{\mHz}{\milli\hertz}
-\newunit{\kHz}{\kilo\hertz}
-\newunit{\MHz}{\mega\hertz}
-\newunit{\GHz}{\giga\hertz}
-\newunit{\THz}{\tera\hertz}
+\bool_new:N \_l_siunitx_product_brackets_bool
+\bool_new:N \_l_siunitx_product_power_bool
+\bool_new:N \_l_siunitx_number_unit_repeat_bool
 %    \end{macrocode}
 %\end{macro}
+%\end{macro} 
+%\end{macro} 
+% 
+%\begin{macro}{\_l_siunitx_number_unit_breaks_bool}
+%\begin{macro}{\_l_siunitx_number_unit_separator_tl}
+% Options for printing units or units with numbers.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  allow-number-unit-breaks .bool_set:N = 
+    \_l_siunitx_number_unit_breaks_bool,
+  multi-part-units          .choice:,
+  multi-part-units
+    / brackets       .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_multi_brackets_bool
+        \bool_set_false:N \_l_siunitx_multi_repeat_bool
+      },
+  multi-part-units
+    / repeat         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_multi_brackets_bool
+        \bool_set_true:N  \_l_siunitx_multi_repeat_bool
+      },
+  multi-part-units
+    / single         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_multi_brackets_bool
+        \bool_set_false:N \_l_siunitx_multi_repeat_bool
+      },
+  number-unit-separator    .tl_set:N   = 
+    \_l_siunitx_number_unit_separator_tl,
+  product-units            .choice:,
+  product-units
+    / brackets       .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / brackets-power .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_product_brackets_bool
+        \bool_set_true:N  \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / power          .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_true:N  \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      }, 
+  product-units
+    / repeat         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_true:N  \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / single         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  multi-part-units      = brackets,
+  number-unit-separator = \,,
+  product-units         = repeat,
+}
+%    \end{macrocode}
+%\end{macro} 
 %\end{macro}
+% 
+%\begin{macro}{\_siunitx_unit_output:nn}
+%\begin{macro}{\_siunitx_unit_output:Vn}
+% For typesetting a unit directly: used by \cs{si} and the \texttt{s}
+% column. The second argument is any options to set locally.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_unit_output:nn #1#2 {
+  \cs_set_eq:NN \_siunitx_unit_format_symbol_aux: 
+    \_siunitx_unit_format_symbol_aux_alt:
+  \cs_set_eq:NN \_siunitx_unit_format_fraction_symbol_aux: 
+    \_siunitx_unit_format_fraction_symbol_aux_alt:
+  \_siunitx_unit_in:nn {#1} {#2}
+  \intexpr_compare:nNnF 
+    { \int_use:N\_l_siunitx_unit_prefix_int } = { 0 } 
+    { 
+      \tl_set:Nx \_l_siunitx_tmpa_tl 
+        {
+          \int_use:N \_l_siunitx_unit_prefix_base_int
+          ^ { \int_use:N \_l_siunitx_unit_prefix_int }
+        }
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \_siunitx_unit_output_number_sep:
+    }
+  \_siunitx_print:nV { unit } \_l_siunitx_unit_tl
+}
+\cs_generate_variant:Nn \_siunitx_unit_output:nn { Vn }
+%    \end{macrocode}
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_unit_output_number_sep:}
+% For printing the number separator.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_number_sep: {
+  \bool_if:NTF \_l_siunitx_number_unit_breaks_bool 
+    { \allowbreak } { \nobreak }    
+  \_siunitx_ensuremath:n { \_l_siunitx_number_unit_separator_tl }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_unit_output_pre_print:}
+%\begin{macro}{\_siunitx_unit_output_print:}
+% The printing functions for units do some simple tests then 
+% actually print there output.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_pre_print: {
+  \tl_if_empty:NF \_l_siunitx_pre_unit_tl
+    { 
+      \nobreak
+      \_siunitx_print:nV { unit } \_l_siunitx_pre_unit_tl 
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_print: {
+  \intexpr_compare:nNnF 
+    { \int_use:N \_l_siunitx_unit_prefix_int } = { 0 } 
+    { 
+      \tl_set:Nx \_l_siunitx_tmpa_tl 
+        {
+          \bool_if:NTF \_l_siunitx_tight_bool 
+            { { \exp_not:V \_l_siunitx_exponent_product_tl } }    
+            { { } \exp_not:V \_l_siunitx_exponent_product_tl { } }        
+          \int_use:N \_l_siunitx_unit_prefix_base_int
+          ^ { \int_use:N \_l_siunitx_unit_prefix_int }
+        }
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+    }
+  \tl_if_empty:NF \_l_siunitx_unit_tl
+    {
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_print:nV { unit } \_l_siunitx_unit_tl 
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Numbers with units}
+%
+% Numbers with units have to be formatted in a more complex way than
+% simply sticking the two together.
+% 
+%\begin{macro}{\_l_siunitx_pre_unit_tl}
+% When there is a pre-unit, it gets stored here.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_pre_unit_tl
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\fmol}
-%\begin{macro}{\pmol}
-%\begin{macro}{\nmol}
-%\begin{macro}{\micmol}
-%\begin{macro}{\mmol}
-%\begin{macro}{\kmol}
-%\changes{v1.1e}{2008/11/18}{New unit}
-% Amounts of substance.
+%
+%\begin{macro}{\_l_siunitx_number_product_int}
+% Used to count up the number of product tokens in a number.
 %    \begin{macrocode}
-\newunit{\fmol}{\femto\mole}
-\newunit{\pmol}{\pico\mole}
-\newunit{\nmol}{\nano\mole}
-\newunit{\micmol}{\micro\mole}
-\newunit{\mmol}{\milli\mole}
-\newunit{\kmol}{\kilo\mole}
+\int_new:N \_l_siunitx_number_product_int
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_combined:nnnn}
+% Printing numbers and units means first processing the units, then 
+% handing off this information to the combined number and unit 
+% processor.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_combined:nnnn #1#2#3#4 {
+  \IfNoValueTF {#3} 
+    { \tl_clear:N \_l_siunitx_pre_unit_tl }
+    {
+      \_siunitx_unit_in:nn {#3} {#1} 
+      \cs_set_eq:NN \_l_siunitx_pre_unit_tl \_l_siunitx_unit_tl
+    }
+  \cs_set_eq:NN \_l_siunitx_brackets_bool 
+    \_l_siunitx_multi_brackets_bool  
+  \_siunitx_combined_unit:nnn {#2} {#4} {#1}
+  \_siunitx_combined_output:n {#2}
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_combined_output:n}
+% Printing the combination of a number and a unit means checking for
+% parsing then parsing the number part.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_combined_output:n #1 {
+  \bool_if:NTF \_l_siunitx_number_parse_bool
+    {
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \bool_set_false:N \_l_siunitx_number_compound_bool
+      \_siunitx_number_output_parse:n {#1}
+    }
+    {
+      \_siunitx_unit_output_pre_print:
+      \_siunitx_print:nn { number } { \_siunitx_ensuremath:n {#1} }
+      \_siunitx_unit_output_print:
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_combined_unit:nnn}
+% In most cases, sorting out the main unit is easy: simply set up for
+% printing using \cs{siunitx_unit_in:nn}. However, if there are multiple
+% parts to the number, and they are to be combined into the unit, then
+% there is more work to do. In either case, the result is the 
+% correctly-prepared unit stored in \cs{_l_siunitx_unit_tl}.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_combined_unit:nnn #1#2#3 {
+  \bool_if:NTF \_l_siunitx_product_power_bool
+    {
+      \_siunitx_combined_product_count:n {#1}
+      \intexpr_compare:nNnTF 
+        { \int_use:N \_l_siunitx_number_product_int } > { 0 } 
+        {
+          \int_incr:N \_l_siunitx_number_product_int
+          \tl_set:Nn \_l_siunitx_tmpa_tl {#2}
+          \tl_set:Nx \_l_siunitx_tmpb_tl 
+            { \tothe { \exp_not:V \_l_siunitx_number_product_int } }
+          \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \_siunitx_unit_in:Vn \_l_siunitx_tmpa_tl {#3}
+        }
+        { \_siunitx_unit_in:nn {#2} {#3} }
+    }
+    { \_siunitx_unit_in:nn {#2} {#3} }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_combined_product_count:n}
+%\begin{macro}[aux]{\_siunitx_combined_product_count_aux:n}
+% For counting how many products are in a number, so that the unit
+% can be adjusted if needed.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_combined_product_count:n #1 {
+  \int_zero:N \_l_siunitx_number_product_int
+  \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+  \tl_map_function:NN \_l_siunitx_input_product_tl 
+    \_siunitx_combined_product_count_aux:N
+}
+\cs_set_protected:Npn \_siunitx_combined_product_count_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_tmpa_tl {#1} 
+    {
+      \int_incr:N \_l_siunitx_number_product_int
+      \tl_remove_in:Nn \_l_siunitx_tmpa_tl {#1}
+      \_siunitx_combined_product_count_aux:N #1
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\kV}
-%\begin{macro}{\mV}
-% Potentials.
+%
+%\subsection{Lists of numbers}
+%
+%\begin{macro}{\_l_siunitx_list_brackets_bool}
+%\begin{macro}{\_l_siunitx_list_repeat_bool}
+% For storing the behaviour of list items with respect to units.
 %    \begin{macrocode}
-\newunit{\kV}{\kilo\volt}
-\newunit{\mV}{\milli\volt}
+\bool_new:N \_l_siunitx_list_brackets_bool
+\bool_new:N \_l_siunitx_list_repeat_bool
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ml}
-%\begin{macro}{\micl}
-%\begin{macro}{\mL}
-%\begin{macro}{\micL}
-%\begin{macro}{\cmc}
-%\begin{macro}{\dmc}
-%\begin{macro}{\cms}
-% Volumes and areas
+%
+%\begin{macro}{\_l_siunitx_list_current_tl}
+%\begin{macro}{\_l_siunitx_list_tl}
+% Two token list variables used to store the list for output.
 %    \begin{macrocode}
-\provideunit{\ml}{\milli\litre}
-\provideunit{\micl}{\micro\litre}
-\provideunit{\mL}{\milli\liter}
-\provideunit{\micL}{\micro\liter}
-\newunit{\cmc}{\centi\metre\cubed}
-\newunit{\dmc}{\deci\metre\cubed}
-\newunit{\cms}{\centi\metre\squared}
+\tl_new:N \_l_siunitx_list_current_tl
+\tl_new:N \_l_siunitx_list_tl
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_list_separator_tl}
+%\begin{macro}{\_l_siunitx_list_separator_final_tl}
+% Settings for lists.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  list-final-separator .tl_set:N = \_l_siunitx_list_separator_final_tl,
+  list-separator       .tl_set:N = \_l_siunitx_list_separator_tl,
+  list-units           .choice:,
+  list-units
+    / brackets .code:n   =
+      {
+        \bool_set_true:N  \_l_siunitx_list_brackets_bool
+        \bool_set_false:N \_l_siunitx_list_repeat_bool
+      },
+  list-units  
+    / repeat .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_list_brackets_bool
+        \bool_set_true:N  \_l_siunitx_list_repeat_bool
+      },
+  list-units  
+    / single .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_list_brackets_bool
+        \bool_set_false:N \_l_siunitx_list_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  list-final-separator = { ~ and ~ },
+  list-separator       = { , ~ },
+  list-units           = repeat,
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_list_numbers:n}
+%\begin{macro}{\_siunitx_list_numbers_aux_i:n}
+%\begin{macro}{\_siunitx_list_numbers_aux_ii:n}
+% Lists of numbers are handled in a very simple fashion. The input
+% list is traversed, and the items are simply placed on a list for
+% output. This uses the internal function \cs{_siunitx_number_output:n}
+% for speed, but does not make any other optimisation. The output list
+% also adds the relevant separators.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_list_numbers:n #1 {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_preunit_tl
+  \_siunitx_list_numbers_aux_i:n {#1}
+}
+\cs_set_protected:Npn \_siunitx_list_numbers_aux_i:n #1 {  
+  \tl_clear:N \_l_siunitx_list_tl
+  \tl_clear:N \_l_siunitx_list_current_tl
+  \tl_map_function:nN {#1} \_siunitx_list_numbers_aux_ii:n    
+  \tl_put_right:NV \_l_siunitx_list_tl 
+    \_l_siunitx_list_separator_final_tl  
+  \tl_put_right:NV \_l_siunitx_list_tl \_l_siunitx_list_current_tl
+  \tl_use:N \_l_siunitx_list_tl 
+}
+\cs_set_protected:Npn \_siunitx_list_numbers_aux_ii:n #1 {
+  \tl_if_empty:NTF \_l_siunitx_list_tl
+    { \tl_set_eq:NN \_l_siunitx_list_tl \_l_siunitx_list_current_tl }
+    { 
+        \tl_put_right:NV \_l_siunitx_list_tl 
+          \_l_siunitx_list_separator_tl
+        \tl_put_right:NV \_l_siunitx_list_tl \_l_siunitx_list_current_tl
+    }
+  \tl_set:Nn \_l_siunitx_list_current_tl 
+    { \_siunitx_combined_output:n {#1} }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\fg}
-%\begin{macro}{\SIfg}
-%\begin{macro}{\kg}
-%\begin{macro}{\fg}
-%\begin{macro}{\pg}
-%\begin{macro}{\nanog}
-%\begin{macro}{\micg}
-%\begin{macro}{\mg}
-%\begin{macro}{\amu}
-% Masses.
+%
+%\begin{macro}{\_siunitx_list_units:nnn}
+% For a list of items with units, the method is to first parse the 
+% unit when repeating (to save time), then to use the number loop above
+% for the actual work. On the other hand, when the unit is only printed
+% once life is easier as the normal unit printer can operate.
 %    \begin{macrocode}
-\newunit{\kg}{\kilo\gram}
+\cs_set_protected:Npn \_siunitx_list_units:nnn #1#2#3 {
+  \bool_if:NTF \_l_siunitx_list_repeat_bool
+    {
+      \_siunitx_unit_in:nn {#2} {#3}
+      \_siunitx_list_numbers_aux_i:n {#1}
+    }
+    {
+      \bool_if:NT \_l_siunitx_list_brackets_bool
+        {
+          \_siunitx_print:nn { number } 
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+        }
+      \_siunitx_list_numbers:n {#1}
+      \bool_if:NT \_l_siunitx_list_brackets_bool
+        {
+          \_siunitx_print:nn { number } 
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+        }   
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_unit_output:nn {#2} {#3}
+    }
+}
 %    \end{macrocode}
-% There is a name clash with \pkg{babel} here in French; hopefully
-% there will not be too many complaints.
+%\end{macro}
+%
+%\subsection{Ranges}
+%
+%\begin{macro}{\_l_siunitx_range_brackets_bool}
+%\begin{macro}{\_l_siunitx_range_repeat_bool}
+% Settings for ranges with units.
 %    \begin{macrocode}
-\AtBeginDocument{\provideunit{\fg}{\femto\gram}}
-\newunit{\SIfg}{\femto\gram}
-\newunit{\pg}{\pico\gram}
-\newunit{\nanog}{\nano\gram}
-\newunit{\micg}{\micro\gram}
-\newunit{\mg}{\milli\gram}
-\newunit{\amu}{\atomicmass}
+\bool_new:N \_l_siunitx_range_brackets_bool
+\bool_new:N \_l_siunitx_range_repeat_bool
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_range_phrase_tl}
+% Simple settings for ranges.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  range-phrase .tl_set:N = \_l_siunitx_range_phrase_tl,
+  range-units  .choice:,
+  range-units  
+    / brackets .code:n   =
+      {
+        \bool_set_true:N  \_l_siunitx_range_brackets_bool
+        \bool_set_false:N \_l_siunitx_range_repeat_bool
+      },
+  range-units  
+    / repeat .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_range_brackets_bool
+        \bool_set_true:N  \_l_siunitx_range_repeat_bool
+      },
+  range-units  
+    / single .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_range_brackets_bool
+        \bool_set_false:N \_l_siunitx_range_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  range-phrase = { ~ to ~ },
+  range-units  = repeat,
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_range_numbers:nn}
+%\begin{macro}{\_siunitx_range_numbers_aux:n}
+% A range of numbers. This is more restrictive than the \cs{num} 
+% function: nothing compound.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_range_numbers:nn #1#2 {
+  \_siunitx_range_numbers_aux:n {#1}
+  \text { \_l_siunitx_range_phrase_tl }
+  \_siunitx_range_numbers_aux:n {#2}
+}
+\cs_set_protected:Npn \_siunitx_range_numbers_aux:n #1 {
+  \bool_if:NTF \_l_siunitx_number_parse_bool 
+    {
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \tl_clear:N \_l_siunitx_number_out_saved_tl
+      \bool_set_false:N \_l_siunitx_number_compound_bool
+      \_siunitx_number_output_parse:n {#1}
+      \bool_if:NT \_l_siunitx_number_compound_bool 
+        { \msg_error:nnx { siunitx } { multi-part-range } {#1} }
+    }
+    { 
+      \_siunitx_unit_output_pre_print:
+      \_siunitx_print:nn { number } {#1}
+      \_siunitx_unit_output_print:
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_range_unit:nnnn}
+% Unit printing is also simple: basically a past-up job.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_range_unit:nnnn #1#2#3#4 {
+  \bool_if:NTF \_l_siunitx_range_repeat_bool
+    {
+      \_siunitx_unit_in:nn {#1} {#2}
+      \_siunitx_range_numbers_aux:n {#3}
+      \text { \_l_siunitx_range_phrase_tl }
+      \_siunitx_range_numbers_aux:n {#4}
+    }
+    {
+      \bool_if:NT \_l_siunitx_range_brackets_bool
+        {
+          \_siunitx_print:nn { number } 
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+        }
+      \_siunitx_range_numbers:nn {#3} {#4}
+      \bool_if:NT \_l_siunitx_range_brackets_bool
+        {
+          \_siunitx_print:nn { number } 
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+        }   
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_unit_output:nn {#1} {#2}
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\subsection{Setting up tables}
+% 
+% There is a slight problem with the \pkg{cellspace} package: it also
+% uses \texttt{S} for a column type  Here, \texttt{S} seems to make
+% more sense for \pkg{siunitx}, with \texttt{C} used for 
+% \pkg{cellspace}. To enable this to work well, the column
+% rewriting code happens \cs{AtBeginDocument}. The \texttt{S} column
+% is deleted from \cs{NC@list} so that no warning appears.
+%    \begin{macrocode}
+\AtBeginDocument {
+  \@ifpackageloaded { cellspace } 
+      {
+        \newcolumntype { C } [1] 
+          { > { \bcolumn #1 \@nil } #1 < { \ecolumn } }
+        \cs_set:Npn \_siunitx_tmp:w #1 \NC@do S #2 \q_stop 
+          { \toks_set:Nn \NC@list { #1 #2 } }
+        \exp_last_unbraced:NV \_siunitx_tmp:w \NC@list \q_stop
+        \cs_gundefine:N \NC@find@S
+      }
+      { }
+}
+%    \end{macrocode}
+%
+%\begin{macro}{\_siunitx_table_rewrite_create:N}
+% The \texttt{s} and \texttt{S} column types are both created using
+% the \pkg{array} package, but with the internal macros redefined
+% to work with optional argument. First, there is a need to do a 
+% quick shuffle with the \cs{NC@list} macro. The \pkg{siunitx} 
+% columns have to be listed first, as otherwise the optional 
+% arguments do not work correctly. So they are added \enquote{by hand}
+% to the appropriate macro.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_rewrite_create:N #1 {
+  \tl_set:Nn \_l_siunitx_tmpa_tl { \NC@do #1 }
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \NC@list
+  \newcolumntype {#1} { }
+  \toks_set:NV \NC@list \_l_siunitx_tmpa_tl
+  \exp_args:NNc \renewcommand * { NC@rewrite@ #1 } [1] [ ] 
+    {
+      \toks_put_right:Nn \@temptokena 
+        {
+          > { \_siunitx_table_collect_begin:Nn #1 {##1} } 
+          c
+          < { \_siunitx_table_print: } 
+        }
+      \NC@find
+    }
+}
+\AtBeginDocument { \_siunitx_table_rewrite_create:N s }
+\AtBeginDocument { \_siunitx_table_rewrite_create:N S }
+%    \end{macrocode}
 %\end{macro}
+%
+%\subsection{Collecting tokens in tables}
+%
+% The table system is in two parts, collecting tokens and typesetting
+% the result.  The collection routine tries to ensure that the 
+% typesetting part only receives real cell contents.
+% 
+%\begin{macro}{\_l_siunitx_table_collect_tl}
+%\begin{macro}{\_l_siunitx_table_collect_pre_tl}
+%\begin{macro}{\_l_siunitx_table_collect_post_tl}
+% Three storage areas.
+%    \begin{macrocode}
+\tl_new:N \_l_siunitx_table_collect_tl
+\tl_new:N \_l_siunitx_table_collect_pre_tl
+\tl_new:N \_l_siunitx_table_collect_post_tl
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\kJ}
-%\begin{macro}{\eV}
-%\begin{macro}{\meV}
-%\begin{macro}{\keV}
-%\begin{macro}{\MeV}
-%\begin{macro}{\GeV}
-%\begin{macro}{\TeV}
-%\begin{macro}{\kWh}
-% Energies.
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_number_valid_tl}
+% As the \texttt{S} column has to make a judgement about tokens which
+% can be part of a number, there is a need to have a list of valid
+% tokens.
 %    \begin{macrocode}
-\newunit{\kJ}{\kilo\joule}
-\newunit{\eV}{\electronvolt}
-\newunit{\meV}{\milli\electronvolt}
-\newunit{\keV}{\kilo\electronvolt}
-\newunit{\MeV}{\mega\electronvolt}
-\newunit{\GeV}{\giga\electronvolt}
-\newunit{\TeV}{\tera\electronvolt}
-\newunit[unitsep=none]{\kWh}{\kilo\watt\hour}
+\tl_new:N \_l_siunitx_number_valid_tl
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_collect_pre_bool}
+%\begin{macro}{\_l_siunitx_table_collect_post_bool}
+% Flags for having found a number in an \texttt{S} column.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_table_collect_pre_bool
+\bool_new:N \_l_siunitx_table_collect_post_bool
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+% 
+%\begin{macro}{\_siunitx_table_collect_begin:Nn}
+%\begin{macro}[aux]{\_siunitx_table_collect_begin_s:}
+%\begin{macro}[aux]{\_siunitx_table_collect_begin_S:}
+% The collector starts by setting up local options, then clears and
+% initialises the storage and testing system.  
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_table_collect_begin:Nn #1#2 {
+  \keys_set:nn { siunitx } {#2}
+  \use:c { _siunitx_table_collect_begin_ #1 : }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_begin_s: {
+  \cs_set_eq:NN \_siunitx_table_collect_token:N 
+    \_siunitx_table_collect_token_s:N
+  \cs_set_eq:NN \_siunitx_table_print: \_siunitx_table_print_s:
+  \_siunitx_table_collect_init_s:
+  \_siunitx_table_collect_get:
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_begin_S: {
+  \cs_set_eq:NN \_siunitx_table_collect_token:N 
+    \_siunitx_table_collect_token_S:N
+  \cs_set_eq:NN \_siunitx_table_print: \_siunitx_table_print_S:
+  \_siunitx_table_collect_init_S:
+  \bool_if:NTF \_l_siunitx_number_parse_bool
+    { \_siunitx_table_collect_get: }
+    { \_siunitx_table_direct: }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_table_collect_braced:n}
+% The collection of braced items depends on the column type. So we
+% start of with an empty definition.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_table_collect_braced:n #1 { }
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_expand:N}
+% The idea here is to expand content if possible.  There are a few 
+% things to note. Only macros which are not long or protected are
+% expanded. There is the possibility that the macro may need the
+% contents of the pre-numeral part to be executed, for example see
+% \cref{tab:xmpl:calc} in the user part of the documentation. 
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_table_collect_expand:N #1 {
+  \cs_if_eq:NNTF #1 \color
+    {
+      \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+        { 
+          \tl_clear:N \_l_siunitx_number_color_tl
+          \tl_clear:N \_l_siunitx_unit_color_tl
+          \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl {#1} 
+        }
+        {
+          \bool_set_true:N \_l_siunitx_table_collect_post_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1}
+        }
+    }
+    {
+      \_siunitx_cs_if_tl:NTF #1 
+        {
+          \tl_use:N \_l_siunitx_table_collect_pre_tl
+          \tl_clear:N \_l_siunitx_table_collect_pre_tl
+          \cs_set_nopar:Npx \_siunitx_table_collect_next: 
+            { \exp_not:N \_siunitx_table_collect_get: \exp_not:V #1 }
+        }
+        {
+          \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+            { \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl {#1} }
+            {
+              \bool_set_true:N \_l_siunitx_table_collect_post_bool
+              \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1}
+            }
+        }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_get:}
+%\begin{macro}{\_siunitx_table_collect_get_aux:}
+% The token collection system first has to check that the next argument
+% does not start with an opening-brace character.  If it does, the 
+% testing is skipped and the braced token is stored.  Otherwise, a check
+% is made against various ignored tokens. At present, things seem to be
+% broken with \pkg{expl3}'s \cs{peek_catcode_ignore_spaces:NTF}, so 
+% everything is done by hand.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_get: {
+  \cs_set_eq:NN \_siunitx_table_collect_next: 
+    \_siunitx_table_collect_get:
+  \cs_set_nopar:Npn \peek_execute_branches: 
+    {
+      \if_catcode:w \exp_not:N \l_peek_token \c_group_begin_token
+        \exp_after:wN \_siunitx_table_collect_braced:n
+      \else:
+        \exp_after:wN \_siunitx_table_collect_not_braced:N
+      \fi:
+    }
+  \peek_after:NN \peek_ignore_spaces_execute_branches:
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\picom}
-%\begin{macro}{\nm}
-%\begin{macro}{\micm}
-%\begin{macro}{\mm}
-%\begin{macro}{\cm}
-%\begin{macro}{\dm}
-%\begin{macro}{\km}
-% Lengths.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_init:}
+% The usual spin-out of basics.
 %    \begin{macrocode}
-\newunit{\picom}{\pico\metre}
-\newunit{\nm}{\nano\metre}
-\newunit{\micm}{\micro\metre}
-\newunit{\mm}{\milli\metre}
-\newunit{\cm}{\centi\metre}
-\newunit{\dm}{\deci\metre}
-\newunit{\km}{\kilo\metre}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init: {
+  \tl_clear:N \_l_siunitx_table_collect_tl
+  \tl_clear:N \_l_siunitx_table_collect_pre_tl
+  \tl_clear:N \_l_siunitx_table_collect_post_tl
+  \bool_set_false:N \_l_siunitx_table_collect_post_bool
+}
+%    \end{macrocode}
+%\end{macro} 
+%\begin{macro}{\_siunitx_table_collect_init_s:}
+%\begin{macro}{\_siunitx_table_collect_init_S:}
+% Some type-specific definitions. In the \texttt{S} case, the 
+% initialisation function for numbers is used to set 
+% \cs{_l_siunitx_number_valid_tl} correctly.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init_s: {
+  \_siunitx_table_collect_init:
+  \bool_set_false:N \_l_siunitx_table_collect_pre_bool
+  \cs_set:Npn \_siunitx_table_collect_braced:n ##1 
+    {
+      \tl_put_right:Nn \_l_siunitx_table_collect_tl { {##1} }
+      \_siunitx_table_collect_next:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init_S: {
+  \_siunitx_number_in_init:
+  \tl_set:Nx \_l_siunitx_number_valid_tl 
+    {
+      \exp_not:V \_l_siunitx_input_complex_tl
+      \exp_not:V \_l_siunitx_input_decimal_tl
+      \exp_not:V \_l_siunitx_input_digit_tl
+      \exp_not:V \_l_siunitx_input_exponent_tl
+      \exp_not:V \_l_siunitx_input_ignore_tl
+      \exp_not:V \_l_siunitx_input_uncert_close_tl
+      \exp_not:V \_l_siunitx_input_uncert_open_tl
+      \exp_not:V \_l_siunitx_input_sign_tl
+      \exp_not:V \_l_siunitx_input_symbol_tl   
+    }
+  \bool_set_true:N \_l_siunitx_table_collect_pre_bool
+  \cs_set:Npn \_siunitx_table_collect_braced:n ##1 
+    {
+      \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+        { \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl { {##1} } }
+        {
+          \bool_set_true:N \_l_siunitx_table_collect_post_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_post_tl { {##1} }
+        }
+      \_siunitx_table_collect_next:
+    }
+}
 %    \end{macrocode}
+%\end{macro} 
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_next:}
+% A holder for the next thing to do.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_next: { }
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_newline:}
+% The end macro needs to come before the new line is called. The 
+% print function is redefined so that it only actually does stuff once.
+% As each cell is a group anyway, there is no need to save the 
+% definition of \cs{siunitx_table_print:}, as it will re-appear on its
+% own.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_newline: {
+  \_siunitx_table_print:
+  \cs_set_eq:NN \_siunitx_table_print: \prg_do_nothing:
+  \tabularnewline
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_not_braced:N}
+%\begin{macro}[aux]{\_siunitx_table_collect_not_braced_aux_i:N}
+%\begin{macro}[aux]{\_siunitx_table_collect_not_braced_aux_ii:N}
+% A few macros are simply passed through to be executed; this is mainly
+% so that the table actually works. The newline function needs its own 
+% function, which is picked up by hand.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced:N #1 {
+  \token_if_eq_meaning:NNF #1 \tex_ignorespaces:D 
+    {
+      \token_if_eq_meaning:NNF #1 \tex_unskip:D
+        { \_siunitx_table_collect_not_braced_aux_i:N #1 }
+    }
+  \_siunitx_table_collect_next:
+}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced_aux_i:N #1 {
+  \cs_set:Npn \_siunitx_table_collect_not_braced_aux_ii:N ##1 
+    {
+      \token_if_eq_meaning:NNT #1 ##1 
+        { \cs_set_eq:NN \_siunitx_table_collect_next: ##1 }
+    }
+  \tl_map_function:nN 
+    { \cs:w \end \endtabular \scan_stop: \_siunitx_table_print: }
+    \_siunitx_table_collect_not_braced_aux_ii:N
+  \token_if_eq_meaning:NNT \_siunitx_table_collect_next: 
+    \_siunitx_table_collect_get: 
+    {
+      \token_if_eq_meaning:NNTF #1 \tabularnewline 
+        {
+          \cs_set_eq:NN \_siunitx_table_collect_next: 
+            \_siunitx_table_collect_newline:
+        }
+        { \_siunitx_table_collect_token:N #1 }
+    }
+}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced_aux_ii:N #1 { }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_collect_token:N}
+%\begin{macro}{\_siunitx_table_collect_token_s:N}
+% For the \texttt{s} column, every token is added to the same storage
+% area, so life is simple.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_table_collect_token:N #1 { }
+\cs_set_protected:Npn \_siunitx_table_collect_token_s:N #1 { 
+  \tl_put_right:Nn \_l_siunitx_table_collect_tl {#1}
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\Sec}
-%\begin{macro}{\as}
-%\begin{macro}{\fs}
-%\begin{macro}{\ps}
-%\begin{macro}{\ns}
-%\begin{macro}{\mics}
-%\begin{macro}{\ms}
-% Finally, times.
+%\end{macro}
+%\begin{macro}{\_siunitx_table_collect_token_S:N}
+% Not so easy for the \texttt{S} column type. If the content is after
+% a number, things are easy.  On the other hand, if the token might be
+% a number, then a check is made. It the token is still unmatched, then
+% it is passed on to the expansion handler.
 %    \begin{macrocode}
-\newunit{\Sec}{\second}
-\newunit{\as}{\atto\second}
-\newunit{\fs}{\femto\second}
+\cs_set_protected:Npn \_siunitx_table_collect_token_S:N #1 {
+  \bool_if:NTF  \_l_siunitx_table_collect_post_bool 
+    { \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1} }
+    {
+      \tl_if_in:NnTF \_l_siunitx_number_valid_tl {#1} 
+        {
+          \bool_set_false:N \_l_siunitx_table_collect_pre_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_tl {#1}
+        }
+        { \_siunitx_table_collect_expand:N #1 }
+    }
+}
 %    \end{macrocode}
-% The letter class (and others) define \cs{ps} for postscripts, so
-% \cs{provideunit} is best here.
+%\end{macro}
+%
+%\subsection{Table printing: general code}
+%
+%\begin{macro}{\_c_siunitx_one_fill_skip}
+% A fixed skip of one \texttt{fill}.
 %    \begin{macrocode}
-\provideunit{\ps}{\pico\second}
-\newunit{\ns}{\nano\second}
-\newunit{\mics}{\micro\second}
-\newunit{\ms}{\milli\second}
+\skip_new:N \_c_siunitx_one_fill_skip
+\skip_set:Nn \_c_siunitx_one_fill_skip { \c_zero_skip plus 1 fill }
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_c_siunitx_table_correction_skip}
+%\begin{macro}{\_siunitx_table_colortbl_correction:}
+% If the package \pkg{colortbl} is loaded, there is a need to allow
+% that it changes how centring is carried out.
+%    \begin{macrocode}
+\skip_new:N \_c_siunitx_table_correction_skip
+\AtBeginDocument {
+  \@ifpackageloaded { colortbl }
+    { 
+      \skip_set:Nn \_c_siunitx_table_correction_skip 
+        { \c_zero_skip plus -0.5 fill } 
+    }
+    { 
+      \skip_set:Nn \_c_siunitx_table_correction_skip 
+        { \c_zero_skip } 
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_colortbl_correction: {
+  \skip_horizontal:n { \_c_siunitx_table_correction_skip }
+  \tex_kern:D \c_zero_skip
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_align_left:n}
+%\begin{macro}{\_siunitx_table_align_right:n}
+% These are simple shortcuts to keep life clearer in the rest of the 
+% code. The idea is that the kern acts as a \enquote{stop} for the 
+% horizontal skip. The correction for \pkg{colortbl} is separate as the
+% spacing needs to be explicitly deleted.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_align_left:n #1 {
+  \_siunitx_table_colortbl_correction:
+  \skip_horizontal:n {#1}
+  \tex_kern:D \c_zero_skip
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_align_right:n #1 {
+  \skip_horizontal:n { \_c_siunitx_one_fill_skip - #1 }
+  \tex_kern:D \c_zero_skip
+  \_siunitx_table_colortbl_correction:
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\subsection{Printing units in \texttt{s} columns}
+%
+% The easiest type of printing is the \texttt{s} column. Here, there is
+% no real problem with alignment. All that has to happen is to print the
+% collected input as the argument to the internal part of an \cs{si}
+% function.
+% 
+%\begin{macro}{\_l_siunitx_table_unit_align_skip}
+% The spacing used is stored as a skip, which needs to be set up first.
+%    \begin{macrocode}
+\skip_new:N \_l_siunitx_table_unit_align_skip
+%    \end{macrocode}
+%\end{macro} 
+% 
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  table-unit-alignment .choice:,
+  table-unit-alignment / center .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip 
+        { \c_zero_skip plus 0.5 fill } 
+    },
+  table-unit-alignment / left   .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip 
+        { \c_zero_skip } 
+    },
+  table-unit-alignment / right  .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip 
+        { \c_zero_skip plus 1 fill } 
+    },
+}
+\keys_set:nn { siunitx } {
+  table-unit-alignment = center
+}
+%    \end{macrocode}
+% 
+%\begin{macro}{\_siunitx_table_print_s:}
+% Actually printing an \texttt{s} column is not very complex. There is
+% some spacing to do at each side, with the main part of the job being
+% to print the material using the internal version of \cs{si}.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_s: { 
+  \_siunitx_table_align_left:n { \_l_siunitx_table_unit_align_skip }
+  \_siunitx_unit_output:Vn \_l_siunitx_table_collect_tl { }
+  \_siunitx_table_align_right:n { \_l_siunitx_table_unit_align_skip }
+}
+%    \end{macrocode}
+%\end{macro} 
+%
+%\subsection{Formatting and printing in tables}
+%
+% With the content grabbed, the next stage is to turn it into formatted
+% output then print it. Most of the formatting is done elsewhere, so
+% most of the work here is in printing.
+% 
+%\begin{macro}{\_l_siunitx_table_center_decimal_bool}
+% A switch for the basic \enquote{decimal marker in the middle}
+% mode.
+%    \begin{macrocode}
+\bool_new:N \_l_siunitx_table_center_decimal_bool
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_fill_box}
+% A box which is only ever filled with \texttt{fil} glue, for padding
+% out numbers.
+%    \begin{macrocode}
+\box_new:N \_l_siunitx_table_fill_box
+%    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</abbr>
-%<*addn>
-%\fi
-%\subsection{Additional (temporary) SI units}
-%\begin{macro}{\angstrom}
-%\begin{macro}{\are}
-%\begin{macro}{\hectare}
-%\begin{macro}{\barn}
-%\begin{macro}{\BAR}
-%\begin{macro}{\bbar}
-%\begin{macro}{\millibar}
-%\begin{macro}{\gal}
-%\begin{macro}{\curie}
-%\begin{macro}{\roentgen}
-%\begin{macro}{\rad}
-%\begin{macro}{\rem}
-%\changes{v1.1c}{2008/10/22}{Uses \cs{provideunit}}
-% Some units are ``temporarily'' acceptable for use in the SI system.
-% These are defined here, although some are in very general use.
+%
+%\begin{macro}{\_l_siunitx_table_fill_dim}
+% Calculating the fill needed can be a bit complicated, so is best
+% done using a dedicated dimension.
 %    \begin{macrocode}
-\ProvidesFile{si-addn.cfg}
-  [2010/02/22 v1.4c siunitx: SI Additional units]
-\provideunit{\angstrom}{\si@sym@ringA}
-\AtBeginDocument{%
-  \ifdefined\Saveangstrom
-    \def\Saveangstrom{\si@sym@ringA}%
-    \def\SaveAngstrom{\si@sym@ringA}%
-  \fi
-}
-\newunit{\are}{a}
-\newunit{\hectare}{\hecto\are}
-\newunit{\barn}{b}
-\newunit{\BAR}{bar}
-\newunit{\bbar}{bar}
-\newunit{\millibar}{\milli\BAR}
-\newunit{\gal}{Gal}
-\newunit{\curie}{Ci}
-\newunit{\roentgen}{R}
-\newunit{\rad}{rad}
-\provideunit{\rem}{rem}
+\dim_new:N \_l_siunitx_table_fill_dim
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_pre_box}
+%\begin{macro}{\_l_siunitx_table_post_box}
+% Boxes for the content before and after the numerical part.
+%    \begin{macrocode}
+\box_new:N \_l_siunitx_table_pre_box
+\box_new:N \_l_siunitx_table_post_box
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_result_box}
+% The box which is actually needed for printing.
+%    \begin{macrocode}
+\box_new:N \_l_siunitx_table_result_box
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_decimal_dim}
+%\begin{macro}{\_l_siunitx_table_exponent_dim}
+%\begin{macro}{\_l_siunitx_table_integer_dim}
+%\begin{macro}{\_l_siunitx_table_mantissa_dim}
+%\begin{macro}{\_l_siunitx_table_marker_dim}
+%\begin{macro}{\_l_siunitx_table_result_dim}
+%\begin{macro}{\_l_siunitx_table_uncert_dim}
+% Dimensions for the various model measurements.
+%    \begin{macrocode}
+\dim_new:N \_l_siunitx_table_decimal_dim
+\dim_new:N \_l_siunitx_table_exponent_dim
+\dim_new:N \_l_siunitx_table_integer_dim
+\dim_new:N \_l_siunitx_table_mantissa_dim
+\dim_new:N \_l_siunitx_table_marker_dim
+\dim_new:N \_l_siunitx_table_result_dim
+\dim_new:N \_l_siunitx_table_uncert_dim
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -11613,55 +10571,122 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_gap_dim}
+% This is used to work out the potential gap between a number and
+% any following material.
+%    \begin{macrocode}
+\dim_new:N \_l_siunitx_table_gap_dim
+%    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</addn>
-%<*accepted>
-%\fi
-%\subsection{Units accepted for use with SI}
-% The units which are accepted but do not fit in the above, plus
-% \cs{percent} which seems to fit into this category.
-%\begin{macro}{\minute}
-%\begin{macro}{\hour}
-%\begin{macro}{\Day}
-%\begin{macro}{\dday}
-%\begin{macro}{\degree}
-%\changes{v1.1c}{2008/10/22}{Uses \cs{provideunit}}
-%\begin{macro}{\Degree}
-%\begin{macro}{\arcmin}
-%\begin{macro}{\arcsec}
-%\begin{macro}{\litre}
-%\begin{macro}{\liter}
-%\begin{macro}{\tonne}
-%\begin{macro}{\neper}
-%\begin{macro}{\bel}
+%
+%\begin{macro}{\_l_siunitx_table_model_prop}
+% To store the model version of a number, used when reserving space.
 %    \begin{macrocode}
-\ProvidesFile{si-accepted.cfg}
-  [2010/02/22 v1.4c siunitx: SI Accepted units]
-\newunit{\minute}{min}
-\newunit{\hour}{h}
-\newunit{\Day}{d}
-\newunit{\dday}{d}
-\ifsi@old@OHM
-  \AtBeginDocument{
-    \provideunit[valuesep=none]{\Degree}{\si@sym@degree}
-  }
-\else
-  \ifsi@gensymb\else
-    \AtBeginDocument{
-      \provideunit[valuesep=none]{\degree}{\si@sym@degree}
-    }
-  \fi
-\fi
-\newunit[valuesep=none]{\arcmin}{\si@sym@minute}
-\newunit[valuesep=none]{\arcsec}{\si@sym@second}
-\newunit{\litre}{l}
-\newunit{\liter}{L}
-\newunit{\tonne}{t}
-\newunit{\neper}{Np}
-\newunit{\bel}{B}
+\prop_new:N \_l_siunitx_table_model_prop
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\_l_siunitx_table_text_align_skip}
+%\begin{macro}{\_l_siunitx_table_number_align_skip}
+% Skips for aligning text and numbers.
+%    \begin{macrocode}
+\skip_new:N \_l_siunitx_table_number_align_skip
+\skip_new:N \_l_siunitx_table_text_align_skip
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%
+%\begin{macro}{\_l_siunitx_table_align_post_bool}
+%\begin{macro}{\_l_siunitx_table_auto_bool}
+%\begin{macro}{\_l_siunitx_table_decimal_int}
+%\begin{macro}{\_l_siunitx_table_exponent_int}
+%\begin{macro}{\_l_siunitx_table_integer_int}
+%\begin{macro}{\_l_siunitx_table_uncert_int}
+%\begin{macro}{\_l_siunitx_table_parse_only_bool}
+%\begin{macro}{\_l_siunitx_table_pre_tl}
+%\begin{macro}{\_l_siunitx_table_post_tl}
+%\begin{macro}{\_l_siunitx_table_sign_exponent_bool}
+%\begin{macro}{\_l_siunitx_table_sign_manitssa_bool}
+% As usual, set up the options.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  table-align-text-post       .bool_set:N 
+    = \_l_siunitx_table_align_post_bool,
+  table-number-alignment      .choice:,
+  table-number-alignment / 
+    center                  .code:n     = 
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip 
+          { \c_zero_skip plus 0.5 fill } 
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment / 
+    center-decimal-marker   .code:n     = 
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip 
+          { \c_zero_skip plus 0.5 fill } 
+        \bool_set_true:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment / 
+    left                    .code:n     = 
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip 
+          { \c_zero_skip } 
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment / 
+    right                   .code:n     = 
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip 
+          { \c_zero_skip plus 1 fill } 
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-text-alignment .choice:,
+  table-text-alignment / 
+    center                  .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_text_align_skip 
+        { \c_zero_skip plus 0.5 fill } 
+    },
+  table-text-alignment / 
+    left                    .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_text_align_skip 
+        { \c_zero_skip } 
+    },
+  table-text-alignment / 
+    right                   .code:n =
+    { 
+      \skip_set:Nn \_l_siunitx_table_text_align_skip 
+        { \c_zero_skip plus 1 fill } 
+    },
+  table-auto-round          .bool_set:N = \_l_siunitx_table_auto_bool,  
+  table-figures-decimal     .int_set:N  = \_l_siunitx_table_decimal_int,
+  table-figures-exponent    .int_set:N  = 
+    \_l_siunitx_table_exponent_int,
+  table-figures-integer     .int_set:N  = \_l_siunitx_table_integer_int,
+  table-figures-uncertainty .int_set:N  = \_l_siunitx_table_uncert_int ,
+  table-parse-only          .bool_set:N = 
+    \_l_siunitx_table_parse_only_bool,
+  table-space-text-pre      .tl_set:N =
+    \_l_siunitx_table_pre_tl,  
+  table-space-text-post     .tl_set:N =
+    \_l_siunitx_table_post_tl,  
+  table-sign-exponent       .bool_set:N = 
+    \_l_siunitx_table_sign_exponent_bool,
+  table-sign-mantissa       .bool_set:N = 
+    \_l_siunitx_table_sign_mantissa_bool
+}
+\keys_set:nn { siunitx } {
+  table-align-text-post  = true,
+  table-number-alignment = center-decimal-marker,
+  table-text-alignment   = center,
+  table-figures-decimal  = 2,
+  table-figures-integer  = 3
+}
+%    \end{macrocode} 
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -11669,154 +10694,916 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%\end{macro} 
 %\end{macro}
+%\end{macro} 
+%
+% A meta-choice for all table alignment is also provided.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  table-alignment .meta:n = 
+    {
+      table-number-alignment = #1,
+      table-text-alignment   = #1,
+      table-unit-alignment   = #1
+    }
+}
+%    \end{macrocode}
+%   
+%\begin{macro}{\_siunitx_table_format_convert:nn} 
+% Another special option. This converts a number format in compacted
+% form into the various internal settings needed. The function is used
+% for the conversion to keep code down.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_format_convert:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl
+    { \int_set:cn { _l_siunitx_table_ #2 _int } { 0 } }
+    { 
+      \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+      \int_set:cn  { _l_siunitx_table_ #2 _int } { \_l_siunitx_tmpa_tl }
+    }
+}
+\keys_define:nn { siunitx } {
+  table-format .code:n    = 
+    {
+      \_siunitx_number_in_parse:n {#1}
+      \_siunitx_table_format_convert:nn { mantissa-integer } { integer }
+      \_siunitx_table_format_convert:nn { mantissa-decimal } { decimal }
+      \_siunitx_table_format_convert:nn { mantissa-uncertainty }
+        { uncert }
+      \_siunitx_table_format_convert:nn { exponent-integer } 
+        { exponent }
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa-sign }
+        { \bool_set_true:N \_l_siunitx_table_sign_mantissa_bool }
+        { \bool_set_false:N \_l_siunitx_table_sign_mantissa_bool }
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { exponent-sign }        
+        { \bool_set_true:N \_l_siunitx_table_sign_mantissa_bool }
+        { \bool_set_false:N \_l_siunitx_table_sign_mantissa_bool }
+      \keys_set:nn { siunitx } { table-number-alignment = center }  
+    },
+}
+%    \end{macrocode}
+%\end{macro}  
+%
+%\begin{macro}{\_siunitx_table_print_S:}
+% The main printing function does a simple test: was there anything
+% found that counts as a number. If there was, most of the detail
+% is handled elsewhere. If there is only test (such as a heading)
+% then it can be printed.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S: {
+  \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+    { 
+      \_siunitx_table_align_left:n { \_l_siunitx_table_text_align_skip }
+      \tl_use:N \_l_siunitx_table_collect_pre_tl
+      \_siunitx_table_align_right:n 
+        { \_l_siunitx_table_text_align_skip }
+    }
+    { 
+      \_siunitx_table_align_left:n 
+        { \_l_siunitx_table_number_align_skip }
+      \_siunitx_table_print_S_aux: 
+      \_siunitx_table_align_right:n 
+        { \_l_siunitx_table_number_align_skip }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+
+%\begin{macro}[aux]{\_siunitx_table_print_S_aux:}
+% The auxiliary function now splits the path. If the number is only
+% being parsed, then it is printed with no more fuss. Otherwise, there
+% is a second choice based on the alignment approach.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_aux: {
+  \bool_if:NTF \_l_siunitx_table_parse_only_bool 
+    { 
+      \tl_use:N \_l_siunitx_table_collect_pre_tl
+      \_siunitx_number_output:V \_l_siunitx_table_collect_tl 
+      \tl_use:N \_l_siunitx_table_collect_post_tl
+    }
+    { 
+      \bool_if:NTF \_l_siunitx_table_center_decimal_bool
+        { \_siunitx_table_print_S_centered: }
+        { \_siunitx_table_print_S_reserved: }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}[aux]{\_siunitx_table_print_S_parse:}
+% A modified version of the number parser for tables.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_parse: {
+  \bool_set_false:N \_l_siunitx_error_bool
+  \_siunitx_number_in_parse:V \_l_siunitx_table_collect_tl 
+  \bool_if:NF \_l_siunitx_error_bool 
+    {
+      \_siunitx_number_process:
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+    }
+}
+%    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_print_S_centered:}
+% When centring the decimal marker, the logic is relatively simple.
+% First, box up the integer part of the number, the entire number and
+% the decimal marker itself.  There is then a measurement to see
+% which part of the number is bigger: before or after the decimal
+% marker. Based on that, a path is chosen. The two then come back
+% together to print any material after the number: the filling 
+% space needed will be equal to the correction required to place notes,
+% \emph{etc}.~flush with the number.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered: {
+  \_siunitx_table_print_S_centered_ends:
+  \dim_compare:nNnTF 
+    { \box_wd:N \_l_siunitx_table_pre_box } = { \c_zero_skip }
+    { \tl_use:N \_l_siunitx_table_collect_pre_tl }
+    { \box_use:N \_l_siunitx_table_pre_box }
+  \_siunitx_table_print_S_parse:
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop 
+    { integer } { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop 
+    { marker }  { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop 
+    { result } { }
+  \box_set_eq:NN \_l_siunitx_table_result_box \_l_siunitx_tmp_box
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_result_dim - \_l_siunitx_table_integer_dim }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop 
+    { mantissa-decimal-marker }
+    {
+      \dim_set:Nn \_l_siunitx_table_fill_dim
+        { \_l_siunitx_table_fill_dim - \_l_siunitx_table_marker_dim }
+    }
+  \dim_compare:nNnTF
+    { \_l_siunitx_table_integer_dim } > { \_l_siunitx_table_fill_dim }
+    { \_siunitx_table_print_S_centered_integer: }
+    { \_siunitx_table_print_S_centered_decimal: }
+  \bool_if:NTF \_l_siunitx_table_align_post_bool
+    { \box_use:N \_l_siunitx_table_post_box }
+    { 
+      \dim_set:Nn \_l_siunitx_table_fill_dim
+        { - \dim_use:N \_l_siunitx_table_fill_dim }
+      \skip_horizontal:N \_l_siunitx_table_fill_dim
+      \box_use:N \_l_siunitx_table_post_box
+      \box_use:N \_l_siunitx_table_fill_box
+    }  
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\percent}
-%\changes{v1.2c}{2009/01/28}{Definition changed}
-%\changes{v1.2d}{2009/02/01}{Definition changed again}
+%\begin{macro}[aux]{\_siunitx_table_print_S_centered_ends:}
+% Here, the material before and after the numerical content is boxed up.
+% The shorter one is then re-boxed so that both sides are the same
+% length: this stops the alignment going out.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_ends: {
+  \hbox_set:Nn \_l_siunitx_table_pre_box
+    { { \tl_use:N \_l_siunitx_table_collect_pre_tl } }
+  \hbox_set:Nn \_l_siunitx_table_post_box
+    { \tl_use:N \_l_siunitx_table_collect_post_tl }
+  \dim_compare:nNnTF 
+    { \box_wd:N \_l_siunitx_table_pre_box  } > 
+    { \box_wd:N \_l_siunitx_table_post_box }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_table_pre_box }
+        { 
+          \hbox_unpack_clear:N \_l_siunitx_table_post_box
+          \tex_hfil:D 
+        }
+    }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+        { \box_wd:N \_l_siunitx_table_post_box }
+        { 
+          \tex_hfil:D 
+          \hbox_unpack_clear:N \_l_siunitx_table_pre_box
+        } 
+    }
+}
+%    \end{macrocode}
+%\end{macro}
+%\begin{macro}[aux]{\_siunitx_table_print_S_centered_integer:}
+%\begin{macro}[aux]{\_siunitx_table_print_S_centered_decimal:}
+% Actually printing the content is a case of calculating a suitable
+% filler box, then printing it and the content.
 %    \begin{macrocode}
-\newunit{\percent}{\char37}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_integer: {
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_integer_dim - \_l_siunitx_table_fill_dim }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box 
+    { \_l_siunitx_table_fill_dim } { \tex_hfil:D }
+  \box_use:N \_l_siunitx_table_result_box
+  \box_use:N \_l_siunitx_table_fill_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_decimal: {
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_fill_dim - \_l_siunitx_table_integer_dim }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box 
+    { \_l_siunitx_table_fill_dim } { \tex_hfil:D }
+  \box_use:N \_l_siunitx_table_fill_box
+  \box_use:N \_l_siunitx_table_result_box
+}
 %    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</accepted>
-%<*physical>
-%\fi
-%\subsection{Units based on physical measurements}
-%\begin{macro}{\si@eVspacea}
-%\begin{macro}{\si@eVspaceb}
-%\begin{macro}{\electronvolt}
-%\begin{macro}{\atomicmassunit}
-%\begin{macro}{\atomicmass}
-% A few units based on physical measurements exist.  For \cs{eV}, the need
-% for a negative kern does make things a bit complicated.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_table_print_S_reserved:}
+% Sorting out a number with reserved space means checking each part
+% in turn. After sorting out the ends, a model number is constructed,
+% and this is then used by the various sub-routines to get the spacing
+% correct.
 %    \begin{macrocode}
-\ProvidesFile{si-physical.cfg}
-  [2010/02/22 v1.4c siunitx: SI Physically-measured units]
-\newcommand*{\si@eVspacea}{\text{\kern-\si@eVcorra}}%
-\newcommand*{\si@eVspaceb}{\text{\kern-\si@eVcorrb}}%
-\newunit{\electronvolt}{e\protect\si@eVspacea V\protect%
-  \si@eVspaceb}
-\newunit{\atomicmass}{u}
-\newunit{\atomicmassunit}{u}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved: {
+  \dim_zero:N \_l_siunitx_table_gap_dim
+  \_siunitx_table_print_S_reserved_ends:
+  \dim_compare:nNnTF 
+    { \box_wd:N \_l_siunitx_table_pre_box } = { \c_zero_skip }
+    { \tl_use:N \_l_siunitx_table_collect_pre_tl }
+    { \box_use:N \_l_siunitx_table_pre_box }
+  \_siunitx_table_print_S_model_create:
+  \bool_if:NT \_l_siunitx_table_auto_bool
+    {
+      \int_set:Nn \_l_siunitx_process_precision_int 
+        { \_l_siunitx_table_decimal_int }
+      \tl_set:Nn \_l_siunitx_round_tl { places }  
+    }
+  \_siunitx_table_print_S_parse: 
+  \intexpr_compare:nNnTF
+    { 
+      \int_use:N \_l_siunitx_table_integer_int 
+        + \int_use:N \_l_siunitx_table_decimal_int 
+    } 
+      > { 0 }
+    { \_siunitx_table_print_S_reserved_mantissa: }
+    { 
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+        { 
+          \msg_error:nnx { siunitx } { table-partial-number } 
+            { a~mantissa }
+        }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { complex-result }
+    { 
+      \msg_error:nnx { siunitx } { table-partial-number } 
+        { a~complex }
+    }
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_table_exponent_int } > { 0 }
+    { \_siunitx_table_print_S_reserved_exponent: }
+    { 
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { exponent-result }
+        { 
+          \msg_error:nnx { siunitx } { table-partial-number } 
+            { an~exponent }
+        }
+    }
+  \bool_if:NTF \_l_siunitx_table_align_post_bool
+    { \box_use:N \_l_siunitx_table_post_box }
+    { 
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+        { \dim_use:N \_l_siunitx_table_gap_dim }
+        { \tex_hfil:D }
+      \dim_set:Nn \_l_siunitx_table_gap_dim
+        { - \dim_use:N \_l_siunitx_table_gap_dim }
+      \skip_horizontal:N \_l_siunitx_table_gap_dim
+      \box_use:N \_l_siunitx_table_post_box
+      \box_use:N \_l_siunitx_table_fill_box
+    }  
+}  
+%    \end{macrocode}
+%\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_reserved_ends:}
+% For the reserved case, the two ends are simply boxed up in correctly
+% created spaces.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_ends: {
+  \hbox_set:Nn \_l_siunitx_tmp_box { \_l_siunitx_table_pre_tl }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { 
+      \tex_hfil:D
+      { \tl_use:N \_l_siunitx_table_collect_pre_tl } 
+    }
+  \hbox_set:Nn \_l_siunitx_tmp_box { \_l_siunitx_table_post_tl }  
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { 
+      \tl_use:N \_l_siunitx_table_collect_post_tl 
+      \tex_hfil:D
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_model_create:}
+%\begin{macro}[aux]{\_siunitx_table_print_S_model_aux:nn}
+% A model value is created from the various numbers set up as
+% options. The main formatting routine is used to get everything sorted
+% out, so that there is no code copying here.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_model_create: {
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \_siunitx_table_print_S_model_aux:nn { integer } { mantissa-integer }
+  \_siunitx_table_print_S_model_aux:nn { decimal } { mantissa-decimal }
+  \_siunitx_table_print_S_model_aux:nn { uncert } 
+    { mantissa-uncertainty }
+  \_siunitx_table_print_S_model_aux:nn { exponent } { exponent-integer }
+  \intexpr_compare:nNnF 
+    { 
+      \int_use:N \_l_siunitx_table_integer_int 
+        + \int_use:N \_l_siunitx_table_decimal_int 
+    }
+      = { 0 }
+    { 
+      \prop_put:Nnn \_l_siunitx_number_in_prop { mantissa } 
+        { true }
+    }
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_table_decimal_int } > { 0 }
+    { 
+      \prop_put:NnV \_l_siunitx_number_in_prop 
+        { mantissa-decimal-marker }
+        \_l_siunitx_output_decimal_tl  
+    }
+  \bool_if:NT \_l_siunitx_table_sign_mantissa_bool
+    { \prop_put:Nnn \_l_siunitx_number_in_prop { mantissa-sign } { - } }
+  \intexpr_compare:nNnT 
+    { \int_use:N \_l_siunitx_table_exponent_int } > { 0 }
+    {  
+      \bool_if:NT \_l_siunitx_table_sign_exponent_bool
+        {
+          \prop_put:Nnn \_l_siunitx_number_in_prop { exponent-sign } 
+            { - } 
+        } 
+    } 
+  \_siunitx_number_process:
+  \_siunitx_number_format: 
+  \prop_set_eq:NN \_l_siunitx_table_model_prop 
+    \_l_siunitx_number_out_prop
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_model_aux:nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { 
+      \prg_replicate:nn { \int_use:c { _l_siunitx_table_ #1 _int } } 
+        { 8 }
+    }
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    { 
+      \prop_put:NnV \_l_siunitx_number_in_prop {#2} \_l_siunitx_tmpa_tl 
+      \prop_put:Nnn  \_l_siunitx_number_in_prop {#1} { true }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_reserved_mantissa:}
+%\begin{macro}[aux]{\_siunitx_table_print_S_reserved_mantissa_aux:n}
+% Printing the mantissa is done by measuring the integer part of the
+% model and the real number, and padding out if necessary. Everything
+% else is straight forward.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_mantissa: {
+  \_siunitx_table_print_S_reserved_mantissa_aux:n { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { mantissa } { }
+  \_siunitx_table_print_S_get_mantissa:Nn 
+    \_l_siunitx_number_out_prop { } 
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \_l_siunitx_table_mantissa_dim }
+    { 
+      \box_use:N \_l_siunitx_table_fill_box
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box
+  \_siunitx_table_print_S_reserved_uncert:n { mantissa }
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_mantissa_aux:n #1 {
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop 
+    { integer } {#1}
+  \_siunitx_table_print_S_get_integer:Nn 
+    \_l_siunitx_number_out_prop {#1}
+  \box_clear:N \_l_siunitx_tmp_box
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+    }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+    { \_l_siunitx_table_integer_dim - \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }  
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop 
+    { decimal } {#1}
+  \box_clear:N \_l_siunitx_tmp_box
+  \_siunitx_table_print_S_get_decimal:Nn 
+    \_l_siunitx_number_out_prop {#1}
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+    }
+  \dim_set:Nn \_l_siunitx_table_gap_dim
+    { 
+      \dim_use:N \_l_siunitx_table_decimal_dim - 
+      \box_wd:N \_l_siunitx_tmp_box 
+    }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\iffalse
-%</physical>
-%\fi
-%
-%\section{Additional configurations}
-% To provide flexibility for people in specific areas, specialised
-% units can be set up.  These are then stored separately to ease use.
 %
-%\iffalse
-%<*synchem>
-%\fi
-%\subsection{Synthetic chemistry}
-%\begin{macro}{\mmHg}
-%\begin{macro}{\molar}
-%\begin{macro}{\Molar}
-%\begin{macro}{\torr}
-%\begin{macro}{\dalton}
-% Some useful units for synthetic chemists; although \cs{mmHg} and
-% \cs{Molar} are outside of the SI system, they are used a lot.
-% These are set up using \cs{provideunit} as people may have their
-% own definitions.
-%    \begin{macrocode}
-\ProvidesFile{si-synchem.cfg}
-  [2010/02/22 v1.4c siunitx: Units for synthetic chemists]
-\requiresiconfigs{prefix}
-\newunit{\mmHg}{mmHg}
-\newunit{\molar}{\mole\per\cubic\deci\metre}
-\newunit{\Molar}{\textsc{m}}
-\newunit{\torr}{Torr}
-\newunit{\dalton}{Da}
+%\begin{macro}{\_siunitx_table_print_S_reserved_uncert:n}
+%\begin{macro}[aux]{\_siunitx_table_print_S_reserved_uncert_aux:n}
+% The uncertainty code is generalised for both real and complex parts.
+% A lot of the logic is similar to the exponent part (the \cs{pm}
+% symbol) or the mantissa (the number measuring). So some of the
+% code is shared.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_uncert:n #1 {
+  \bool_if:NT \_l_siunitx_uncert_sep_bool
+    {
+      \intexpr_compare:nNnTF
+        { \int_use:N \_l_siunitx_table_uncert_int } > { 0 }
+        { \_siunitx_table_print_S_reserved_uncert_aux:n {#1} }
+        { 
+          \prop_if_in:NnT \_l_siunitx_number_out_prop 
+            { #1 -uncertainty }
+            { 
+              \msg_error:nn { siunitx } { table-partial-number } 
+                { an~uncertainty }
+            }
+        }
+    }        
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_uncert_aux:n #1 {
+  \_siunitx_table_print_S_reserved_uncert_pm:n {#1}     
+  \_siunitx_table_print_S_reserved_mantissa_aux:n { #1 -uncertainty }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { uncert } {#1}
+  \_siunitx_table_print_S_get_uncert:Nn \_l_siunitx_number_out_prop {#1}
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \_l_siunitx_table_uncert_dim }
+    { 
+      \box_use:N \_l_siunitx_table_fill_box
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_uncert_pm:n #1 {
+  \tl_clear:N \_l_siunitx_tmpb_tl
+  \_siunitx_number_format_join_uncert_pm:
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { { } \exp_not:V \_l_siunitx_tmpb_tl { } }
+  \hbox_set:Nn \_l_siunitx_table_result_box
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpb_tl }
+  \prop_if_in:NnF \_l_siunitx_number_out_prop { #1 -uncertainty }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+        { \box_wd:N \_l_siunitx_table_result_box } { \tex_hfil:D }
+    }
+ \box_use:N \_l_siunitx_table_result_box
+}
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_reserved_exponent:}
+%\begin{macro}[aux]{\_siunitx_table_print_S_reserved_exponent_product:}
+%\begin{macro}[aux]
+%  {\_siunitx_table_print_S_reserved_exponent_product_aux_i:}
+%\begin{macro}[aux]
+%  {\_siunitx_table_print_S_reserved_exponent_product_aux_ii:}
+% Most of the code for the exponent is concerned with getting the
+% product sign correct.Other than that, the exponent result is quite
+% easy to handle: just print it with some filling.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_exponent: {
+  \dim_zero:N \_l_siunitx_table_gap_dim
+  \_siunitx_table_print_S_reserved_exponent_product:   
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop 
+    { exponent } { }
+  \_siunitx_table_print_S_get_exponent:Nn 
+    \_l_siunitx_number_out_prop { }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box 
+    { \_l_siunitx_table_exponent_dim }
+    {
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box 
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_exponent_product: {
+  \tl_clear:N \_l_siunitx_tmpa_tl
+  \box_clear:N \_l_siunitx_table_result_box
+  \prop_if_in:NnTF \_l_siunitx_table_model_prop { mantissa-result }
+    { \_siunitx_table_print_S_reserved_exponent_product_aux_i: }
+    { 
+      \prop_if_in:NnT \_l_siunitx_table_model_prop { complex-result }
+        { \_siunitx_table_print_S_reserved_exponent_product_aux_i: }
+    }
+ \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_exponent_product_aux_i: {
+  \tl_set_eq:NN \_l_siunitx_tmpa_tl \_l_siunitx_exponent_product_tl
+  \bool_if:NT \_l_siunitx_tight_bool 
+    {  
+      \tl_set:Nx \_l_siunitx_tmpa_tl 
+        { { \exp_not:V \_l_siunitx_tmpa_tl } }
+    }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { 
+      \exp_not:N \_siunitx_ensuremath:n 
+        { { } \exp_not:V \_l_siunitx_tmpa_tl { } }
+    }
+  \hbox_set:Nn \_l_siunitx_table_result_box
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { exponent-result }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { mantissa-result } 
+        {
+          \prop_if_in:NnF \_l_siunitx_number_out_prop { complex-result } 
+            { 
+              \_siunitx_table_print_S_reserved_exponent_product_aux_ii:
+            }
+        }
+    }
+    { \_siunitx_table_print_S_reserved_exponent_product_aux_ii: }
+
+}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_reserved_exponent_product_aux_ii: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \box_wd:N \_l_siunitx_table_result_box } { \tex_hfil:D }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_print_S_measure:Nnn}
+% The measuring code recovers whatever is needed into 
+% \cs{_l_siunitx_tmpa_tl} (as this is internal code, that is okay).
+% The content is then boxed up and measured: if there is nothing to do,
+% a bit of time can be saved by not boxing up at all.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_measure:Nnn #1#2#3 {
+  \use:c { _siunitx_table_print_S_get_ #2 :Nn } #1 {#3}
+  \tl_if_empty:NTF \_l_siunitx_tmpa_tl
+    { \dim_set:cn { _l_siunitx_table_ #2 _dim } { \c_zero_skip } }
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+      \dim_set:cn { _l_siunitx_table_ #2 _dim } 
+        { \box_wd:N \_l_siunitx_tmp_box }
+    }
+}
+%    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</synchem>
-%<*hep>
-%\fi
-%\subsection{High-energy physics}
-% Some units inspired by \pkg{hepunits}.
+%\begin{macro}{\_siunitx_table_print_S_get_decimal:Nn}
+% Grabbing the decimal part is a simple operation.
 %    \begin{macrocode}
-\ProvidesFile{si-hep.cfg}
-  [2010/02/22 v1.4c siunitx: Units for high-energy physics]
-\requiresiconfigs{prefix,named}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_get_decimal:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -decimal } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
 %    \end{macrocode}
-%\begin{macro}{\micron}
-%\begin{macro}{\mrad}
-%\begin{macro}{\gauss}
-% These specific to high-energy physics, but are not defined
-% elsewhere in \currpkg.\footnote{It is not clear from
-% \pkg{hepunits}, but the assumption is that \cs{mrad} represents
-% millirad and not milliradian.}
+%\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_get_exponent:Nn}
+% Getting the exponent part is quite easy.
 %    \begin{macrocode}
-\provideunit{\micron}{\micro\metre}
-\newunit{\mrad}{\milli\rad}
-\newunit{\gauss}{G}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_get_exponent:Nn #1#2 {
+  \prop_get:NnN #1 { exponent-result } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_get_integer:Nn}
+% Getting the integer part of a number means that the sign also has be
+% considered, even if there is no actual integer. This leas to a 
+% slightly odd approach here.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_get_integer:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -sign } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+  \prop_get:NnN #1 { #2 -integer } \_l_siunitx_tmpb_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpb_tl
+    { \tl_clear:N \_l_siunitx_tmpb_tl }
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+}
+%    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_get_mantissa:Nn}
+% The mantissa without any uncertainty is needed by the reserved
+% space routine. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn 
+  \_siunitx_table_print_S_get_mantissa:Nn #1#2 {
+  \prop_get:NnN #1 { mantissa } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\clight}
-%\begin{macro}{\eVperc}
-% The speed of light is used in units for the area, although of
-% course it is not strictly a unit.  However, this makes it easier to
-% use in other units.
+%\begin{macro}{\_siunitx_table_print_S_get_marker:Nn} 
+% The decimal marker is always going to be boxed up using the 
+% standard version, not any possible copied value. So the code can be
+% kept quite clear.
 %    \begin{macrocode}
-\newunit{\clight}{\ensuremath{\mathnormal{c}}}
-\newunit{\eVperc}{\eV\per\clight}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_marker:Nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { 
+      \exp_not:N \_siunitx_ensuremath:n 
+        { \exp_not:V \_l_siunitx_output_decimal_tl }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%\begin{macro}{\_siunitx_table_print_S_get_result:Nn} 
+% Getting the result values is easy. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_result:Nn #1#2 {
+  \prop_get:NnN #1 { result } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\nanobarn}
-%\begin{macro}{\picobarn}
-%\begin{macro}{\femtobarn}
-%\begin{macro}{\attobarn}
-%\begin{macro}{\zeptobarn}
-%\begin{macro}{\yoctobarn}
-% Various prefixed barns.
+%\begin{macro}{\_siunitx_table_print_S_get_uncert:Nn} 
 %    \begin{macrocode}
-\newunit{\nanobarn}{\nano\barn}
-\newunit{\picobarn}{\pico\barn}
-\newunit{\femtobarn}{\femto\barn}
-\newunit{\attobarn}{\atto\barn}
-\newunit{\zeptobarn}{\zepto\barn}
-\newunit{\yoctobarn}{\yocto\barn}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_uncert:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -uncertainty } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\subsection{Direct printing in \texttt{S} columns}
+%
+% When number parsing is turned off the usual approach to printing
+% tabular material is not suitable. Instead, the strategy used by
+% \pkg{dcolumn} can be applied, which requires the decimal marker to
+% be made active in math mode.
+% 
+%\begin{macro}{\_siunitx_table_direct:}
+% The main part of the system simply makes a choice about the 
+% methods to use.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct: {
+  \m@th  
+  \bool_if:NTF \_l_siunitx_table_center_decimal_bool
+    { \_siunitx_table_direct_centered: }
+    { \_siunitx_table_direct_reserved: }
+}
+%    \end{macrocode}
+%\end{macro} 
+%
+%\begin{macro}{\_siunitx_table_direct_centered:}
+%\begin{macro}[aux]{\_siunitx_table_direct_centered_aux:N}
+%\begin{macro}{\_siunitx_table_direct_centered_end:}
+% When centring the content about a decimal marker, the trick is
+% to collect everything into two boxes and then compare the sizes.
+% In that sense this is very similar to the normal method, except that
+% it will work with non-numerical input.
+%    \begin{macrocode}
+\char_make_active:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered: {
+  \cs_set_eq:NN \_siunitx_table_print: 
+    \_siunitx_table_direct_centered_end:
+  \hbox_set:Nn \_l_siunitx_tmp_box 
+    { \_siunitx_ensuremath:n { \_l_siunitx_output_decimal_tl } }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box 
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }  
+  \hbox_set:Nn \_l_siunitx_table_pre_box 
+    \c_group_begin_token 
+      \c_math_shift_token
+      \tl_map_function:NN \_l_siunitx_input_decimal_tl
+        \_siunitx_table_direct_centered_aux:N
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered_aux:N #1 {
+  \char_set_lccode:nn { `\@ } { `#1 }
+  \char_set_mathcode:nn { `#1 } { 32768 }
+  \tl_to_lowercase:n { \cs_set_nopar:Npn @ }
+    {
+      \c_math_shift_token
+      \c_group_end_token
+      \hbox_set:Nn \_l_siunitx_table_post_box
+        \c_group_begin_token
+          \c_math_shift_token
+          \_l_siunitx_output_decimal_tl
+    }
+}
+\char_make_letter:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered_end: {
+    \c_math_shift_token
+  \c_group_end_token
+  \dim_compare:nNnTF 
+    { \box_wd:N \_l_siunitx_table_pre_box } > 
+    { \box_wd:N \_l_siunitx_table_post_box }
+    { 
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_table_pre_box }
+        {
+          \hbox_unpack:N \_l_siunitx_table_post_box
+          \tex_hfil:D
+        }
+    }
+    { 
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+        { \box_wd:N \_l_siunitx_table_post_box }
+        {
+          \tex_hfil:D
+          \hbox_unpack:N \_l_siunitx_table_pre_box
+        }
+    }
+  \box_use:N \_l_siunitx_table_pre_box
+  \box_use:N \_l_siunitx_table_post_box
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\_siunitx_table_direct_reserved:}
+%\begin{macro}[aux]{\_siunitx_table_direct_reserved_aux:N}
+%\begin{macro}{\_siunitx_table_direct_reserved_end:}
+% The plan here is to box up the entire number using the information
+% available about the size of the two parts. Relatively easy,
+% but needs a bit of measuring. The first box here does need to use
+% \cs{tex_hill:D} as \texttt{fil} glue will not work.
+%    \begin{macrocode}
+\char_make_active:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved: {
+  \cs_set_eq:NN \_siunitx_table_print: 
+    \_siunitx_table_direct_reserved_end:
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { \prg_replicate:nn { \_l_siunitx_table_integer_int } { 8 } } 
+  \hbox_set:Nn \_l_siunitx_tmp_box 
+    { 
+      \_siunitx_ensuremath:n 
+        { 
+          \bool_if:NT \_l_siunitx_table_sign_mantissa_bool { - }
+          \_l_siunitx_tmpa_tl 
+        } 
+    }
+  \dim_set:Nn \_l_siunitx_table_integer_dim
+    { \box_wd:N \_l_siunitx_tmp_box }  
+  \tl_set:Nx \_l_siunitx_tmpa_tl 
+    { \prg_replicate:nn { \_l_siunitx_table_decimal_int } { 8 } }
+  \hbox_set:Nn \_l_siunitx_tmp_box 
+    { 
+      \_siunitx_ensuremath:n 
+        { 
+          \_l_siunitx_output_decimal_tl
+          \_l_siunitx_tmpa_tl
+        } 
+    }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box 
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }  
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box 
+    { \_l_siunitx_table_integer_dim }
+    \c_group_begin_token 
+      \c_math_shift_token
+      \tl_map_function:NN \_l_siunitx_input_decimal_tl
+        \_siunitx_table_direct_reserved_aux:N 
+      \tex_hfill:D  
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved_aux:N #1 {
+  \char_set_lccode:nn { `\@ } { `#1 }
+  \char_set_mathcode:nn { `#1 } { 32768 }
+  \tl_to_lowercase:n { \cs_set_nopar:Npn @ }
+    {
+        \c_math_shift_token
+      \c_group_end_token
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_tmp_box }
+        \c_group_begin_token
+          \c_math_shift_token
+          \_l_siunitx_output_decimal_tl
+    }
+}
+\char_make_letter:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved_end: {
+    \c_math_shift_token
+    \tex_hfil:D
+  \c_group_end_token  
+  \_siunitx_table_align_left:n { \_l_siunitx_table_number_align_skip }
+  \box_use:N \_l_siunitx_table_pre_box
+  \box_use:N \_l_siunitx_table_post_box
+  \_siunitx_table_align_right:n { \_l_siunitx_table_number_align_skip }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\nb}
-%\begin{macro}{\pb}
-%\begin{macro}{\fb}
-%\begin{macro}{\ab}
-%\begin{macro}{\zb}
-%\begin{macro}{\yb}
-% Abbreviations for the same, but using \cs{provideunit} to avoid any
-% clashes.
+%\end{macro}
+%
+%\subsection{Symbols}
+%
+% Not all units use letters alone for their symbol. This raises two 
+% problems. First, the symbols need to work in math and in text mode.
+% Second, the user needs to be able to adjust each symbol.
+% 
+%\begin{macro}{\_l_siunitx_redefine_symbols_bool}
+% Only one setting applies here!
 %    \begin{macrocode}
-\provideunit{\nb}{\nano\barn}
-\provideunit{\pb}{\pico\barn}
-\provideunit{\fb}{\femto\barn}
-\provideunit{\ab}{\atto\barn}
-\provideunit{\zb}{\zepto\barn}
-\provideunit{\yb}{\yocto\barn}
+\keys_define:nn { siunitx } {
+  redefine-symbols .bool_set:N = \_l_siunitx_redefine_symbols_bool,
+}
+\keys_set:nn { siunitx } {
+  redefine-symbols = true
+}
+%    \end{macrocode}
+%\end{macro} 
+%
+% The redefinition of symbols has to do a number of checks to ensure
+% that there are no clashes.
+%    \begin{macrocode}
+\AtBeginDocument {
+  \bool_if:NT \_l_siunitx_redefine_symbols_bool 
+    {
+      \@ifpackageloaded { textcomp } 
+        {
+          \keys_set:nn { siunitx } 
+            {
+              math-degree = \text { \textdegree },
+              text-degree  = \textdegree,
+            }
+          \@ifpackageloaded { mathptmx } { } 
+            {
+              \keys_set:nn { siunitx } { text-micro = \textmu }
+              \@ifpackageloaded { fourier } { }
+                { \keys_set:nn { siunitx } { text-ohm = \textohm } } 
+            }
+          \tl_if_eq:nVT { OT1 } \encodingdefault 
+            { 
+              \keys_set:nn { siunitx } 
+                {
+                  math-angstrom = \text { \capitalring { A } },
+                  text-angstrom = \capitalring { A }
+                }
+            }
+        } { }
+      \@ifpackageloaded { upgreek } 
+        {
+          \keys_set:nn { siunitx } 
+            { math-ohm = \Upomega }
+        } { }
+    }
+}
+%    \end{macrocode}
+%
+%\begin{macro}{\_l_siunitx_angstrom_math_tl}
+%\begin{macro}{\_l_siunitx_arcminute_math_tl}
+%\begin{macro}{\_l_siunitx_arcsecond_math_tl}
+%\begin{macro}{\_l_siunitx_celsius_math_tl}
+%\begin{macro}{\_l_siunitx_degree_math_tl}
+%\begin{macro}{\_l_siunitx_micro_math_tl}
+%\begin{macro}{\_l_siunitx_ohm_math_tl}
+% The symbol storage macros are created separately for math and text
+% mode, although this is all pretty similar. The default definitions use
+% what is generally available, except for those for micro, where 
+% Computer Modern does not have the appropriate symbol at all. For the 
+% math mode omega option, the "\text{\ensuremath{...}}" construction
+% deals with the case where \cs{mathnormal} has the wrong symbol.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  math-angstrom   .tl_set:N = \_l_siunitx_angstrom_math_tl,
+  math-arcminute  .tl_set:N = \_l_siunitx_arcminute_math_tl,
+  math-arcsecond  .tl_set:N = \_l_siunitx_arcsecond_math_tl,
+  math-celsius    .tl_set:N = \_l_siunitx_celsius_math_tl,
+  math-degree     .tl_set:N = \_l_siunitx_degree_math_tl,
+  math-micro      .tl_set:N = \_l_siunitx_micro_math_tl,
+  math-ohm        .tl_set:N = \_l_siunitx_ohm_math_tl
+}
+\keys_set:nn { siunitx } {
+  math-angstrom  = \text { \AA },
+  math-arcminute = { } ^ { \prime },
+  math-arcsecond = { } ^ { \prime \prime },
+  math-celsius   = { } ^ { \circ } \kern - \scriptspace \mathrm { C },
+  math-degree    = { } ^ { \circ },
+  math-micro     = \text { \_c_siunitx_mu_tl },
+  math-ohm       = \text { \ensuremath { \_c_siunitx_omega_tl } },
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -11824,82 +11611,75 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\iffalse
-%</hep>
-%<*astro>
-%\fi
-%\subsection{Astronomy}
-%\begin{macro}{\parsec}
-%\begin{macro}{\lightyear}
-% For astronomy, the \cs{parsec} unit is needed.
+%\end{macro}
+%\begin{macro}{\_l_siunitx_angstrom_text_tl}
+%\begin{macro}{\_l_siunitx_arcminute_text_tl}
+%\begin{macro}{\_l_siunitx_arcsecond_text_tl}
+%\begin{macro}{\_l_siunitx_celsius_text_tl}
+%\begin{macro}{\_l_siunitx_degree_text_tl}
+%\begin{macro}{\_l_siunitx_micro_text_tl}
+%\begin{macro}{\_l_siunitx_ohm_text_tl}
+% Text versions are similar.
 %    \begin{macrocode}
-\ProvidesFile{si-astro.cfg}
-  [2010/02/22 v1.4c siunitx: Units for astronomy]
-\newunit{\parsec}{pc}
-\newunit{\lightyear}{ly}
+\keys_define:nn { siunitx } {
+  text-angstrom  .tl_set:N = \_l_siunitx_angstrom_text_tl,
+  text-arcminute .tl_set:N = \_l_siunitx_arcminute_text_tl,
+  text-arcsecond .tl_set:N = \_l_siunitx_arcsecond_text_tl,
+  text-celsius   .tl_set:N = \_l_siunitx_celsius_text_tl,
+  text-degree    .tl_set:N = \_l_siunitx_degree_text_tl,
+  text-micro     .tl_set:N = \_l_siunitx_micro_text_tl,
+  text-ohm       .tl_set:N = \_l_siunitx_ohm_text_tl,
+}
+\keys_set:nn { siunitx } {
+  text-angstrom  = \AA,
+  text-arcminute = \ensuremath { { } ^ { \prime } },
+  text-arcsecond = \ensuremath { { } ^ { \prime \prime } },
+  text-celsius   = 
+    \ensuremath { { } ^ { \circ } \kern - \scriptspace \text { C } },
+  text-degree    = \ensuremath { { } ^ { \circ } },
+  text-micro     = \_c_siunitx_mu_tl ,
+  text-ohm       = \ensuremath { \_c_siunitx_omega_tl },
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\iffalse
-%</astro>
-%<*geophys>
-%\fi
-%\subsection{Geophysics}
-%\begin{macro}{\lightyear}
-% The unit \cs{gon} is useful here.
-%    \begin{macrocode}
-\ProvidesFile{si-geophys.cfg}
-  [2010/02/22 v1.4c siunitx: Units for astronomy]
-\newunit{\gon}{gon}
-%    \end{macrocode}
 %\end{macro}
-%\iffalse
-%</geophys>
-%<*chemeng>
-%\fi
-%\subsection{Chemical engineering}
-%\begin{macro}{\gmol}
-%\begin{macro}{\kgmol}
-%\begin{macro}{\lbmol}
-% For astronomy, the \cs{parsec} unit is needed.
-%    \begin{macrocode}
-\ProvidesFile{si-chemeng.cfg}
-  [2010/02/22 v1.4c siunitx: Units for chemical engineering]
-\newunit{\gmol}{g\text{-}mol}
-\newunit{\kgmol}{kg\text{-}mol}
-\newunit{\lbmol}{lb\text{-}mol}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\iffalse
-%</chemeng>
-%<*binary>
-%\fi
-%\subsection{Binary units}
-%\begin{macro}{\kibi}
-%\begin{macro}{\mebi}
-%\begin{macro}{\gibi}
-%\begin{macro}{\tebi}
-%\begin{macro}{\pebi}
-%\begin{macro}{\exbi}
-%\begin{macro}{\zebi}
-%\begin{macro}{\yobi}
-% The binary units, as specified by the IEC and made available by
-% \SIunits. First, the binary prefixes.
+%\end{macro}
+%
+%\begin{macro}{\_siunitx_symbol_new:n}
+% For creating the outer symbol macro.
 %    \begin{macrocode}
-\ProvidesFile{si-binary.cfg}
-  [2010/02/22 v1.4c siunitx: Binary units]
-\newprefix[binary]{\kibi}{10}{Ki}
-\newprefix[binary]{\mebi}{20}{Mi}
-\newprefix[binary]{\gibi}{30}{Gi}
-\newprefix[binary]{\tebi}{40}{Ti}
-\newprefix[binary]{\pebi}{50}{Pi}
-\newprefix[binary]{\exbi}{60}{Ei}
-\newprefix[binary]{\zebi}{70}{Zi}
-\newprefix[binary]{\yobi}{80}{Yi}
+\cs_set_protected:Npn \_siunitx_symbol_new:n #1 {
+  \cs_set_protected_nopar:cpn { SIUnitSymbol #1 } 
+    {
+      \mode_if_math:TF 
+        { \tl_to_lowercase:n { \use:c { _l_siunitx_ #1 _math_tl } } }
+        { \tl_to_lowercase:n { \use:c { _l_siunitx_ #1 _text_tl } } }
+    }
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\SIUnitSymbolAngstrom}
+%\begin{macro}{\SIUnitSymbolArcminute}
+%\begin{macro}{\SIUnitSymbolArcsecond}
+%\begin{macro}{\SIUnitSymbolCelsius}
+%\begin{macro}{\SIUnitSymbolDegree}
+%\begin{macro}{\SIUnitSymbolMicro}
+%\begin{macro}{\SIUnitSymbolOhm}
+% The wrapper macros are created.
+%    \begin{macrocode}
+\_siunitx_symbol_new:n { Angstrom }
+\_siunitx_symbol_new:n { Arcminute }
+\_siunitx_symbol_new:n { Arcsecond }
+\_siunitx_symbol_new:n { Celsius }
+\_siunitx_symbol_new:n { Degree } 
+\_siunitx_symbol_new:n { Micro }
+\_siunitx_symbol_new:n { Ohm }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -11907,442 +11687,548 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\bit}
-%\begin{macro}{\byte}
-% Now the units.
+%
+%\subsection{Working with other packages}
+%
+%\begin{macro}{\_l_siunitx_pgf_link_clist}
+%\begin{macro}{\_siunitx_pgf_link:}
+% Here, the settings used by \pkg{siunitx} are translated into those for
+% \pkg{pgf}. Things could be done more efficiently, but the logic would 
+% be more difficult to follow.
 %    \begin{macrocode}
-\newunit{\bit}{bit}
-\newunit{\byte}{B}
+\clist_new:N \_l_siunitx_pgf_link_clist
+\cs_set_protected_nopar:Npn \_siunitx_pgf_link: {
+  \clist_clear:N \_l_siunitx_pgf_link_clist
+  \tl_if_eq:VnT \_l_siunitx_round_tl { figure }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist { fixed }
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { fixed~zerofill = true }
+    }
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    { precision = \int_use:N \_l_siunitx_process_precision_int }
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    { 
+      set~decimal~separator = 
+        { { \exp_not:V \_l_siunitx_output_decimal_tl } }
+    }  
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    { 
+      set~thousands~separator = 
+        { \exp_not:V \_l_siunitx_group_sep_tl } 
+    }  
+  \bool_if:NTF \_l_siunitx_group_four_bool
+    { 
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { min~exponent~for~1000~sep = 3 }
+    }
+    { 
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { min~exponent~for~1000~sep = 4 }
+    }
+  \bool_if:nF
+    {  
+      \_l_siunitx_group_decimal_bool ||
+      \_l_siunitx_group_integer_bool  
+    }  
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { min~exponent~for~1000~sep = 999 } 
+    }
+  \bool_if:NTF \_l_siunitx_process_integer_zero_bool
+    { 
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { skip~0. = false }
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { skip~0. = true }
+    } 
+  \tl_if_eq:VnTF \_l_siunitx_process_sign_tl { + }
+    { 
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { showpos = true }
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist 
+        { showpos = false }
+    } 
+  \group_begin:  
+  \cs_set_nopar:Npx \_siunitx_tmp:w
+    {
+      \group_end:
+      \exp_not:N \pgfqkeys 
+        { /pgf/number~format }
+        { \exp_not:V \_l_siunitx_pgf_link_clist }
+    } 
+  \_siunitx_tmp:w   
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %
-%\iffalse
-%</binary>
-%\fi
-%
-%\section{Loadable locales}
-% Some short files to provide the correct settings for various places.
-%
-%\iffalse
-%<*UK>
-%\fi
-%\subsection{United Kingdom}
-% This is identical to the USA locale, and contains the package
-% default values.\footnote{The package author is in the UK.}
-%    \begin{macrocode}
-\ProvidesFile{si-UK.cfg}
-  [2010/02/22 v1.4c siunitx: UK locale]
-\sisetup{
-  unitsep=thin,
-  expproduct=times,
-  valuesep=thin,
-  decimalsymbol=fullstop,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
-%    \end{macrocode}
-%\iffalse
-%</UK>
-%<*USA>
-%\fi
-%\subsection{United States}
-% The same as for the UK.
-%    \begin{macrocode}
-\ProvidesFile{si-USA.cfg}
-  [2010/02/22 v1.4c siunitx: USA locale]
-\sisetup{
-  unitsep=thin,
-  expproduct=times,
-  valuesep=thin,
-  decimalsymbol=fullstop,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
-%    \end{macrocode}
-%\iffalse
-%</USA>
-%<*DE>
-%\fi
-%\subsection{Germany}
-% Germany, hopefully.
-%    \begin{macrocode}
-\ProvidesFile{si-DE.cfg}
-  [2010/02/22 v1.4c siunitx: Germany locale]
-\sisetup{
-  unitsep=cdot,
-  valuesep=thin,
-  decimalsymbol=comma,
-  expproduct=cdot,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ bis }}}
-%    \end{macrocode}
-%\iffalse
-%</DE>
-%<*ZA>
-%\fi
-%\subsection{South Africa}
-% Design decisions taken from the same section of \SIstyle.
-%    \begin{macrocode}
-\ProvidesFile{si-ZA.cfg}
-  [2010/02/22 v1.4c siunitx: South Africa locale]
-\sisetup{
-  unitsep=cdot,
-  valuesep=thin,
-  expproduct=times,
-  decimalsymbol=comma,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
-%    \end{macrocode}
-%\iffalse
-%</ZA>
-%\fi
-%
-%\section{Emulation code}
-% Each emulation mode loads an appropriate definition file.  This
-% then alters the package defaults, and defines new macros provided
-% by the emulated package.
-%
-%\iffalse
-%<*units>
-%\fi
-%\subsection{\units}
-% The very first thing to do here is a reload check, as things
-% could go wrong with \unitsdef emulation.
-%    \begin{macrocode}
-\si@ifloaded{units}{\endinput}{}
-%    \end{macrocode}
-% The \units package is quite easy to emulate, as it only has a
-% few options and macros. There is also no error checking in
-% \units for conflicting options, so users probably expect none.
-%    \begin{macrocode}
-\ProvidesFile{si-units.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of units]
-\si@emulating{units}{1998/08/04 v0.9b}
-\si@ifloaded{SIunits}
-  {\si@emclash{units}{SIunits}\endinput}{}
-\si@ifloaded{sistyle}
-  {\si@emclash{units}{sistyle}\endinput}{}
-%    \end{macrocode}
-% To emulate \units, \cs{per} must give fractions.
-%    \begin{macrocode}
-\sisetup{per=fraction,fraction=nice,obeybold,inlinebold=maths,
-  ,obeymode}
-\ifsi@old@tight
-  \sisetup{valuesep=thin}
-\fi
-\ifsi@old@loose
-  \sisetup{valuesep=space}
-\fi
-\ifsi@old@ugly
-  \sisetup{fraction=ugly}
-\fi
+%\subsection{Messages}
+%
+% Lots of messages, all of them together in one block to make life
+% easier.
+%    \begin{macrocode}
+\msg_set:nnnn { siunitx } { bad-arc-sign } 
+  { Incorrect~use~of~sign~in~degree-minute-second~angle. }
+  { Only~the~highest~value~part~of~an~angle~can~have~a~sign. }
+\msg_set:nnnn { siunitx } { duplicate-complex-root-token } 
+  { Duplicate~complex~root~token~'#1'~in~input. }
+  { Only~one~complex~root~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-decimal-token } 
+  { Duplicate~decimal~marker~token~'#1'~in~input. }
+  { Only one decimal marker token can appear in a single number. }
+\msg_set:nnnn { siunitx } { duplicate-exponent-token } 
+  { Duplicate~exponent~marker~token~'#1'~in~input. }
+  { Only~one~exponent~marker~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-quotient-token } 
+  { Duplicate~quotient~token. } 
+  { Only~one~quotient~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-sticky-per } 
+  { Duplicate~\token_to_str:N \per. } 
+  {
+    When~the~'sticky-per'~option~is~active,~only~one 
+    \token_to_str:N \per \\
+    may~appear~in~a~unit.
+  }
+\msg_set:nnnn { siunitx } { empty-arc } 
+  { Empty~degree-minute-second~angle. }
+  { The~angle~given~does~not~contain~any~numbers. }
+\msg_set:nnnn { siunitx } { empty-uncertainty }
+  { Empty~uncertainty~given~in~'#1'. }
+  { The~number~given~contains~an~empty~uncertainty. }
+\msg_set:nnnn { siunitx } { ending-product-token }
+  { Misplaced~product~token. }
+  { A~number~cannot~end~with~a~product~token. }
+\msg_set:nnnn { siunitx } { ending-quotient-token } 
+  { Misplaced~quotient~token. }
+  { A~number~cannot~end~with~a~quotient~token. }
+\msg_set:nnnn { siunitx } { invalid-arc-format } 
+  { Invalid~degree-minute-second angle~'#1'. }
+  {
+    Angles~given~in~degree-minute-second~format~should~contain~two~';'\\
+    symbols~to~divide~up~the~parts~of~the~input.\\
+  }
+\msg_set:nnnn { siunitx } { invalid-number } 
+  { Invalid~numerical~input~'#1'. }
+  {
+    The~input given~as~a~number~does~not~make~logical~sense.\\
+    This~happens,~for example,~if~a~number~only~contains~a~sign.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-exponent }
+  { Invalid~exponent~in~numerical~input~'#1'. }
+  {
+    The~exponent`part~of~a~number~cannot~contain~an~uncertainty~or~
+    complex~part.\\
+    The~input~given~appears~to~contain~one~of~these~in~the~exponent.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-number }
+  { Invalid~token~'#1'~in~numerical~input. }
+  {
+    Numbers~can~only~contain~tokens~defined~using~the~
+    'input-...'~options:\\
+    the~token~'#1'~is~not~set~up~as~a~valid~part~of~a~number.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-uncertainty }
+  { Invalid~uncertainty~in~numerical~input~'#1'. }
+  {
+    The~uncertainty~part~of~a~number~may~only~contain~digits~or~
+    symbols.
+  }
+\msg_set:nnnn { siunitx } { literal-unit }
+  { Literal~units~disabled. }
+  {
+    You~gave~the~literal~input~'#1'\\
+    but~literal~unit~output~is~disabled.
+  }
+\msg_set:nnnn { siunitx } { misplaced-sign-token } 
+  { Misplaced~sign~token~'#1'. }
+  { Sign~tokens~can~only~come~at~the~beginning~of~a~number. }
+\msg_set:nnnn { siunitx } { misplaced-complex-root-token } 
+  { Misplaced~complex~token~in~numerical~input~'#1'. } 
+  {
+    The~root~token~must~come~either~before~or~after~the~real~digits\\
+    of~the~complex~part.
+  }
+\msg_set:nnnn { siunitx } { misplaced-uncertainty-token } 
+  { Misplaced~uncertainty~token~'#1'. }
+  {
+    The~uncertainty~in~a~number~must~be~given~between~a~set~of~
+    delimiters~as~defined~by~the\\
+    \c_space_tl \c_space_tl
+    'input-open-uncertainty'~and~'input-close-uncertainty'\\
+    options.
+  }
+\msg_set:nnnn { siunitx } { multi-part-range } 
+  { Numerical~range~with~multiple~parts. }
+  {
+    The~input~'#1'~is~a~number~which~has~more~than~one~part.\\
+    Ranges~can~only~contain~one~number~in~each~part.
+  }
+\msg_set:nnn { siunitx } { option-not-available }
+  { Option~'#1'~not~available~in~strict~mode. }
+\msg_set:nnn { siunitx } { option-preamble-only }
+  { Option~'#1'~only~available~in~the~preamble. }
+\msg_set:nnnn { siunitx } { prefix-base-mismatch }
+  { Prefix~bases~do~not~match. }
+  {
+    You~have~asked~for~prefixes~to~be~converted~into~a~power,\\
+    but~the~bases~do~not~match.
+  }
+\msg_set:nnn { siunitx } { prefix-only } 
+  { Prefix~with~no~unit. }
+\msg_set:nnnn { siunitx } { qualifier-before-unit } 
+  { Qualifier~before~unit. }
+  { Unit~qualifiers~have~to~follow~after~units,~not~before~them. }
+\msg_set:nnnn { siunitx } { restricted-number } 
+  { Token~'#1'~forbidden~in~restricted~numerical~input. }
+  { 
+    The~current~input~must~be~a~real~number~and~cannot~contain: \\
+    \c_space_tl -~an~exponent; \\
+    \c_space_tl -~an~uncertainty; \\
+    \c_space_tl -~a~complex~part.
+  }
+\msg_set:nnnn { siunitx } { starting-product-token } 
+  { Misplaced~product~token. }
+  { A~number~cannot~begin~with~a~product~token. }
+\msg_set:nnnn { siunitx } { starting-quotient-token } 
+  { Misplaced~quotient~token. }
+  { A~number~cannot~begin~with~a~quotient~token. }
+\msg_set:nnnn { siunitx } { table-partial-number }
+  { No~space~reserved~for~#1~\msg_line_context:. }
+  { 
+    The~number~in~the~current~table~cell~contains~#1~part, \\
+    but~you~did~not~reserve~any~space~to~print~it: \\
+    it~will~be~missing~in~the~output.
+  }
+\msg_set:nnnn { siunitx } { unknown-configuration-file } 
+  { Unknown~configuration~'#1'. }
+  { The~configuration~file~'siunitx-#1.cfg'~was~not~found. }
+\msg_set:nnnn { siunitx } { unknown-option } 
+  { Unknown~option~'#1'. }
+  { 
+    The~option~file~'#1'~is~not~known~by~siunitx: \\
+    perhaps~it~is~spelled~incorrectly.
+  }
 %    \end{macrocode}
-%\begin{macro}{\unit}
-%\doarg{number}
-%\darg{unit}
-% The \units version of \cs{unit} is similar to \cs{SI}.  Here and
-% in \cs{unitfrac} the \cs{num} macro is used; thus the number given
-% really has to be a number.  However, if users are using \currpkg
-% rather than \units they should expect more checking of input.  As
-% the \units package uses the current mode, this has to be
-% detected.
-%    \begin{macrocode}
-\si@newrobustcmd*{\unit}[2][]{%
-  \ifmmode
-    \SI{#1}{#2}%
-  \else
-    \SI[obeyfamily,obeyitalic]{#1}{#2}%
-  \fi}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\unitfrac}
-%\doarg{number}
-%\darg{numerator}
-%\darg{denominator}
-% \cs{unitfrac} is a bit more of a hack.
-%    \begin{macrocode}
-\si@newrobustcmd*{\unitfrac}[3][]{%
-  \begingroup
-    \si@fam@mode%
-    \ifmmode\else
-      \sisetup{obeyfamily,obeyitalic}%
-    \fi
-    \si@ifnotmtarg{#1}
-      {\num{#1}\ensuremath{\si@valuesep}}%
-    \si@frac{#2}{#3}
-  \endgroup}
-%    \end{macrocode}
-%\end{macro}
-%\iffalse
-%</units>
-%\fi
-%\iffalse
-%<*unitsdef>
-%\fi
-%\subsection{\unitsdef}
-% The package begins with the usual identification of what is
-% happening.  Although \file{si-units.cfg} makes the same checks,
-% the error will make more sense if it comes here, in the event of a
-% clash.
-%    \begin{macrocode}
-\ProvidesFile{si-unitsdef.cfg}
-  [2010/02/22 v1.4c siunitx:
-   Emulation of unitsdef]
-\si@emulating{unitsdef}{2005/01/04 v0.2}
-\si@ifloaded{SIunits}
-  {\si@emclash{unitsdef}{SIunits}\endinput}{}
-\si@ifloaded{sistyle}
-  {\si@emclash{unitsdef}{sistyle}\endinput}{}
-%    \end{macrocode}
-% Emulation of \units is needed for \unitsdef to work.
-%    \begin{macrocode}
-\requiresiconfigs{units}
-%    \end{macrocode}
-% The \unitsdef package loads some packages that \currpkg does not.
-% In particular, it loads \pkg{textcomp} and \pkg{fontenc}.  This
-% could be important for output, and so the same is done here.
-%    \begin{macrocode}
-\RequirePackage{textcomp}
-\RequirePackage[T1]{fontenc}
-%    \end{macrocode}
-% The multitude of package options for \unitsdef need to be handled.
-%    \begin{macrocode}
-\sisetup{mode=text,allowoptarg,prespace}
-\ifsi@old@noxspace
-  \sisetup{xspace=false}
-\fi
+%    
+%\subsection{Design-level macros}
+% 
+%\begin{macro}{\DeclareBinaryPrefix}
+%\begin{macro}{\DeclareSIPostPower}
+%\begin{macro}{\DeclareSIPrefix}
+%\begin{macro}{\DeclareSIPrePower}
+%\begin{macro}{\DeclareSIQualifier}
+%\begin{macro}{\DeclareSIUnit}
+%\begin{macro}{\DeclareSIUnitWithOptions}
+% The macros for creating units and so on are in design name space.
+% Basically, a set of shuffles for arguments.
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \DeclareBinaryPrefix #1#2#3 {
+  \_siunitx_declare_prefix:Nnnn #1 {#2} { 2 } {#3}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPostPower #1#2 {
+  \_siunitx_declare_power_after:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPrefix #1#2#3 {
+  \_siunitx_declare_prefix:Nnnn #1 {#2} { 10 } {#3}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPrePower #1#2 {
+  \_siunitx_declare_power_before:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIQualifier #1#2 {
+  \_siunitx_declare_qualifier:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIUnit #1#2 {
+  \_siunitx_declare_unit:Nnn #1 {#2} { }
+}
+\cs_set_protected_nopar:Npn \DeclareSIUnitWithOptions #1#2#3 {
+  \_siunitx_declare_unit:Nnn #1 {#2} {#3}
+}
 %    \end{macrocode}
-% The various options for loading unit abbreviations have to be
-% handled. Here, any request to avoid abbreviations prevents any
-% loading.
+%\end{macro}
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%\end{macro}
+%\end{macro}
+%\end{macro}
+% 
+% None of this should be done after the preamble.
 %    \begin{macrocode}
-\ifsi@old@noabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nofrequncyabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nomolabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@novoltageabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@novolumeabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@noweightabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@noenergyabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nolengthabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@notimeabbr
-  \sisetup{noload=abbr}
-\fi
+\@onlypreamble \DeclareBinaryPrefix
+\@onlypreamble \DeclareSIPostPower
+\@onlypreamble \DeclareSIPrefix
+\@onlypreamble \DeclareSIPrePower
+\@onlypreamble \DeclareSIQualifier
+\@onlypreamble \DeclareSIUnit
+\@onlypreamble \DeclareSIUnitWithOptions
 %    \end{macrocode}
-%\begin{macro}{\unitvaluesep}
-% To emulate the \cs{unitvaluesep} macro, a hack is needed of the original
-% \pkg{xkeyval} macro for \opt{valuesep}, as well of course as a definition
-% of the macro itself.
+%    
+%\begin{macro}{\SendSettingsToPgf}
+% A settings transfer function.
 %    \begin{macrocode}
-\newcommand*{\unitvaluesep}{\,}
-\renewcommand*{\si@valuesep}{\text{\unitvaluesep}}
-\define@choicekey*+[si]{key}{valuesep}[\si@tempa]
-  {space,thin,med,medium,thick,none}
-  {\renewcommand*\unitvaluesep\@nameuse{si@fix@##1}%
-   \si@log@debug{Option valuesep set to ##1}}
-  {\si@log@debug{Option valuesep set to ##1}%
-   \renewcommand*\unitvaluesep{##1}}
+\cs_set_protected_nopar:Npn \SendSettingsToPgf { \_siunitx_pgf_link: }
+\@onlypreamble \SendSettingsToPgf
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\unitsignonly}
-%\begin{macro}{\ilu}
-%\begin{macro}{\arc}
-% Some rather straight-forward definitions, with just a bit of fun to
-% get the spacing correct.
-%    \begin{macrocode}
-\let\unitsignonly\si
-\si@newrobustcmd*{\ilu}[2][]{%
-  \begingroup
-    #1\unitvaluesep%
-    \unit{#2}%
-  \endgroup}
-\let\arc\ang
+%
+%\subsection{Document macros}
+%
+% The user document macros are all collected together here for ease.
+% 
+%\begin{macro}{\ang}
+% The \cs{ang} function does very little beyond setting the local
+% keys and passing on the input.
+%    \begin{macrocode}
+\NewDocumentCommand \ang { o > { \SplitArgument { 2 } { ; } } m } {
+  \group_begin:
+    \IfNoValueF {#1} 
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_angle_output:nnn #2
+  \group_end:
+}
 %    \end{macrocode}
 %\end{macro}
+% 
+%\begin{macro}{\num}
+% The \cs{num} macro is quite simple: read the number, check it is 
+% correct then print it. 
+%    \begin{macrocode}
+\NewDocumentCommand \num { o m } {
+  \group_begin:
+    \IfNoValueF {#1} 
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_number_output:n {#2}
+  \group_end:
+}
+%    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\unitSIdef}
-%\begin{macro}{\si@unitSIdef}
-% The \unitsdef package uses a different approach to setting the font
-% inside its version of \cs{SI}.  The problem is the same as for
-% \cs{unitvaluesep}, but with the added problem that \currpkg uses
-% \cs{csname} \ldots \cs{endcsname}.
+%
+%\begin{macro}{\numlist}
+% Lists of numbers are trivially easy to work with.
 %    \begin{macrocode}
-\newcommand*{\unitSIdef}{\upshape}
-\newcommand*{\si@unitSIdef}{\unitSIdef\selectfont}
-\sisetup{textrm=si@unitSIdef}
+\NewDocumentCommand \numlist { o > { \SplitList { ; } } m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_list_numbers:n {#2}
+  \group_end:
+}
 %    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\per}
-% Rather awkwardly, \unitsdef uses \cs{per} in a different way to
-% \currpkg.
-%    \begin{macrocode}
-\let\per\relax
-\si@newrobustcmd*{\per}[2]{%
-  \begingroup
-    \si@xspacefalse
-    \renewcommand*{\unitvaluesep}{}%
-    \unitfrac{#1}{#2}%
-  \endgroup}
+%
+%\begin{macro}{\numrange}
+% A very simple approach is taken here: this is not intended for 
+% anything complicated.
+%    \begin{macrocode}
+\NewDocumentCommand \numrange { o m m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_range_numbers:nn {#2} {#3}
+  \group_end:
+}
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\unittimes}
-%\begin{macro}{\unitsep}
-%\begin{macro}{\unitsuperscript}
-% Some pretty straight-forward stuff again; notice that the automatic
-% analyser for units has to be turned off for this to work.
-%    \begin{macrocode}
-\newcommand*{\unittimes}{\ensuremath{\cdot}}
-\newcommand*{\unitsep}{\,}
-\renewcommand*{\si@unt@unithook}{\si@unt@litouttrue}
-\sisetup{unitsep=none}
-\newcommand*{\unitsuperscript}{\tothe}
+%
+%\begin{macro}{\si}
+% The \cs{si} macro needs to pass options through to the internal
+% function as well as setting them here. This is used so that options
+% set for a unit can be overridden on a one-off basis.
+%    \begin{macrocode}
+\NewDocumentCommand \si { o m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_unit_output:nn {#2} { } }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_unit_output:nn {#2} {#1}
+      }
+  \group_end:
+}
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\SIlist}
+%\begin{macro}{\SIrange}
+% Lists and range of values are handled in a very similar way.
+% Everything is kept relatively simple, and so there is not too much
+% complexity. In theory the two could be combined together, but 
+% the differences between the two make this less desirable.
+%    \begin{macrocode}
+\NewDocumentCommand \SIlist { o > { \SplitList { ; } } m m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_list_units:nnn {#2} {#3} { }  }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_list_units:nnn {#2} {#3} {#1} 
+      }
+  \group_end:
+}
+\NewDocumentCommand \SIrange { o m m m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_range_unit:nnnn {#4} { } {#2} {#3} }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_range_unit:nnnn {#4} {#1} {#2} {#3}
+      }
+  \group_end:
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\newnosepunit}
-%\begin{macro}{\renewnosepunit}
-% Simple aliases.
+%
+%\begin{macro}{\SI}
+% The main \cs{SI} function follows the same pattern as the previous
+% ones.
 %    \begin{macrocode}
-\newcommand*{\newnosepunit}{\newunit[valuesep=none]}
-\newcommand*{\renewnosepunit}{\renewunit[valuesep=none]}
+\NewDocumentCommand \SI { o m o m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_combined:nnnn { } {#2} {#3} {#4} }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_combined:nnnn {#1} {#2} {#3} {#4}
+      }
+  \group_end:
+}
 %    \end{macrocode}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\setTextOmega}
-%\begin{macro}{\setMathOmega}
-%\begin{macro}{\setTextmu}
-%\begin{macro}{\setMathmu}
-%\begin{macro}{\setTextCelsius}
-%\begin{macro}{\setMathCelsius}
-%\begin{macro}{\setMathDegree}
-%\begin{macro}{\setTextDegree}
-% Controlling symbols is a simple translation job; as only one
-% setting is used by \currpkg in text mode, a bit of extra work is
-% needed.
+% 
+%\begin{macro}{\sisetup}
+% The set up macro simply moves to the correct path and executes 
+% whatever has been passed.
 %    \begin{macrocode}
-\newcommand*{\setTextOmega}[2]{%
-  \renewcommand*{\si@textOmega}{%
-      \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathOmega}[1]{\sisetup{mathsOmega=#1}}
-\newcommand*{\setTextmu}[2]{%
-  \renewcommand*{\si@textmu}{%
-    \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathmu}[1]{\sisetup{mathsmu=#1}}
-\newcommand*{\setTextCelsius}[2]{%
-  \renewcommand*{\si@textcelsius}{%
-    \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathCelsius}[1]{\sisetup{mathscelsius=#1}}
-\newcommand*{\setMathDegree}[2]{%
-  \renewcommand*{\si@textdegree}{%
-    \begingroup%
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setTextDegree}[1]{\sisetup{textdegree=#1}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% The \opt{ohm} and \opt{OHM} options are checked, and some sanity is
-% ensured.  This needs to happen before loading the configuration
-% files.
-%    \begin{macrocode}
-\ifsi@old@OHM
-  \ifsi@old@ohm
-    \si@log@inf{Both `ohm' and `OHM' options given\MessageBreak
-      Using default behaviour for unitsdef}
-    \expandafter\expandafter\expandafter\si@old@OHMfalse
-  \fi
-\fi
+\NewDocumentCommand \sisetup { m } {
+  \keys_set:nn { siunitx } {#1}
+}
 %    \end{macrocode}
-%\begin{macro}{\liter}
-%\begin{macro}{\ton}
-%\begin{macro}{\days}
-% Tonne is spelled as ``ton'' by \unitsdef, which is wrong in the UK
-% at least (\SI{1}{ton} $=$ \SI{40}{cwt} $=$ \SI{2240}{lb}!).
-%    \begin{macrocode}
-\ifsi@old@liter
-  \ifsi@old@LITER
-    \si@log@inf{Both `liter' and `LITER' options
-      given\MessageBreak Using default behaviour for unitsdef}
-  \else
-    \renewunit{\liter}{l}
-  \fi
-\fi
-\newunit{\ton}{t}
-\newunit{\days}{d}
+%\end{macro}
+%
+%\subsection{Precautions for section headings}
+%
+% There are two issues to be handled for section headings, \emph{etc}.
+% First, within the \cs{addcontentline} macro the various unit functions 
+% need to be \cs{protected}. Secondly, there is a need to worry about
+% \pkg{hyperref}, and ensure that everything works cleanly and with
+% no unnecessary warnings.
+% 
+%\begin{macro}{\_siunitx_contents_add:N}
+% An updated version of \cs{addtocontents} which will ensure that
+% everything works properly. Using \cs{token_to_str:N} means that
+% there is no problem with the asynchronous nature of TeX's writing
+% mechanism.
+%    \begin{macrocode}
+\AtBeginDocument {
+  \cs_set:Npn \addtocontents #1#2
+    {
+      \protected@write \@auxout
+        {
+          \cs_set_eq:NN \label \use_none:n 
+          \cs_set_eq:NN \index \use_none:n  
+          \cs_set_eq:NN \glossary\use_none:n
+          \tl_map_function:NN \_l_siunitx_declare_list_tl 
+            \_siunitx_contents_add:N 
+        }
+        { \token_to_str:N \@writefile {#1} {#2} }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_contents_add:N #1 {
+  \cs_set_nopar:Npn #1 { \token_to_str:N #1 }
+}
+%    \end{macrocode}
+%\end{macro} 
+% 
+%\begin{macro}{\_siunitx_contents_bookmarks:}
+% The idea here is two-fold. First, all of the unit macros are set
+% up to simply print their literal interpretation: this is hopefully
+% good enough for most bookmark situations. Secondly, the document
+% commands are made expandable. This allows a bit of re-arrangement
+% of the input, removes any set up options (which are being ignored)
+% and stops \pkg{hyperref} issuing a warning. 
+%    \begin{macrocode}
+\cs_set_protected_nopar:Npn \_siunitx_contents_bookmarks: {
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_print_literal_aux:N
+  \msg_redirect_name:nnn { LaTeX / xparse } { redefine-command } 
+    { none }
+  \cs_set_eq:NN \num      \_siunitx_bookmark_num:w
+  \cs_set_eq:NN \numrange \_siunitx_bookmark_numrange:w
+  \cs_set_eq:NN \si       \_siunitx_bookmark_si:w
+  \cs_set_eq:NN \SI       \_siunitx_bookmark_SI:w
+  \cs_set_eq:NN \SIrange  \_siunitx_bookmark_SIrange:w
+  \cs_set_nopar:Npn \SIUnitSymbolAngstrom  { \AA }
+  \cs_set_nopar:Npn \SIUnitSymbolArcminute { ' }
+  \cs_set_nopar:Npn \SIUnitSymbolArcsecond { '' }
+  \cs_set_nopar:Npn \SIUnitSymbolCelsius   { \textcelsius }
+  \cs_set_nopar:Npn \SIUnitSymbolDegree    { \textdegree }
+  \cs_set_nopar:Npn \SIUnitSymbolMicro     { \textmu }
+  \cs_set_nopar:Npn \SIUnitSymbolOhm       { [ohm] }
+}
 %    \end{macrocode}
+%\end{macro} 
+%\begin{macro}{\_siunitx_bookmark_num:w}
+%\begin{macro}{\_siunitx_bookmark_numrange:w}
+%\begin{macro}{\_siunitx_bookmark_si:w}
+%\begin{macro}{\_siunitx_bookmark_SI:w}
+%\begin{macro}{\_siunitx_bookmark_SIrange:w}
+% To keep things fast, expandable versions of the document commands
+% are created only once. These are then used if necessary to remove
+% and re-order arguments in an expandable fashion.
+%    \begin{macrocode}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_num:w { o m } {#2}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_numrange:w { o m m } 
+  { #2 \_l_siunitx_range_phrase_tl #3 }
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_si:w { o m } {#2}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_SI:w { o m o m } 
+  { \IfNoValueF {#3} {#3} #2 ~ #4 }
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_SIrange:w
+  { o m m m } { #2 ~ #4 \_l_siunitx_range_phrase_tl #3 ~ #4 }
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\picometer}
-%\begin{macro}{\nanometer}
-%\begin{macro}{\micrometer}
-%\begin{macro}{\millimeter}
-%\begin{macro}{\centimeter}
-%\begin{macro}{\decimeter}
-%\begin{macro}{\kilometer}
-% Extra distances.
+%\end{macro}
+%
+% A short check to get things working.
 %    \begin{macrocode}
-\newunit{\picometer}{\pico\meter}
-\newunit{\nanometer}{\nano\meter}
-\newunit{\micrometer}{\micro\meter}
-\newunit{\millimeter}{\milli\meter}
-\newunit{\centimeter}{\centi\meter}
-\newunit{\decimeter}{\deci\meter}
-\newunit{\kilometer}{\kilo\meter}
+\AtBeginDocument {
+  \@ifpackageloaded { hyperref } 
+    { \pdfstringdefDisableCommands { \_siunitx_contents_bookmarks: } }
+    { }
+}
 %    \end{macrocode}
+%
+%\subsection{Physical units}
+%
+%\begin{macro}{\kilogram}
+%\begin{macro}{\metre}
+%\begin{macro}{\meter}
+%\begin{macro}{\mole}
+%\begin{macro}{\kelvin}
+%\begin{macro}{\candela}
+%\begin{macro}{\second}
+%\begin{macro}{\ampere}
+% The basic SI units are always defined, including both variants for
+% metre.
+%    \begin{macrocode}
+\DeclareSIUnit \kilogram { \kilo \gram }
+\DeclareSIUnit \metre    { m }
+\DeclareSIUnit \meter    { \metre }
+\DeclareSIUnit \mole     { mol }
+\DeclareSIUnit \second   { s }
+\DeclareSIUnit \ampere   { A }
+\DeclareSIUnit \kelvin   { K }
+\DeclareSIUnit \candela  { cd }
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -12350,32 +12236,38 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\femtoliter}
-%\begin{macro}{\picoliter}
-%\begin{macro}{\nanoliter}
-%\begin{macro}{\microliter}
-%\begin{macro}{\milliliter}
-%\begin{macro}{\centiliter}
-%\begin{macro}{\deciliter}
-%\begin{macro}{\hectoliter}
-%\begin{macro}{\cubicmeter}
-%\begin{macro}{\cubicmicrometer}
-%\begin{macro}{\cubicmillimeter}
-% Volumes with US spellings.
+%
+%\begin{macro}{\gram}
+% The gram is an odd unit as it is needed for the base unit kilogram.
 %    \begin{macrocode}
-\newunit{\femtoliter}{\femto\liter}
-\newunit{\picoliter}{\pico\liter}
-\newunit{\nanoliter}{\nano\liter}
-\newunit{\microliter}{\micro\liter}
-\newunit{\milliliter}{\milli\liter}
-\newunit{\centiliter}{\centi\liter}
-\newunit{\deciliter}{\deci\liter}
-\newunit{\hectoliter}{\hecto\liter}
-\newunit{\cubicmeter}{\meter\cubed}
-\newunit{\cubicmicrometer}{\micro\meter\cubed}
-\newunit{\cubicmillimeter}{\milli\meter\cubed}
+\DeclareSIUnit \gram { g }
 %    \end{macrocode}
 %\end{macro}
+%
+%\begin{macro}{\yocto}
+%\begin{macro}{\zepto}
+%\begin{macro}{\atto}
+%\begin{macro}{\femto}
+%\begin{macro}{\pico}
+%\begin{macro}{\nano}
+%\begin{macro}{\micro}
+%\begin{macro}{\milli}
+%\begin{macro}{\centi}
+%\begin{macro}{\deci}
+% The various SI multiple prefixes are defined here: first the small
+% ones. 
+%    \begin{macrocode}
+\DeclareSIPrefix \yocto { y } { -24 }
+\DeclareSIPrefix \zepto { z } { -21 }
+\DeclareSIPrefix \atto  { a } { -18 }
+\DeclareSIPrefix \femto { f } { -15 }
+\DeclareSIPrefix \pico  { p } { -12 }
+\DeclareSIPrefix \nano  { n } { -9 }
+\DeclareSIPrefix \micro { \SIUnitSymbolMicro } { -6 }
+\DeclareSIPrefix \milli { m } { -3 }
+\DeclareSIPrefix \centi { c } { -2 }
+\DeclareSIPrefix \deci  { d } { -1 }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
@@ -12386,374 +12278,236 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\squaremeter}
-%\begin{macro}{\squarecentimeter}
-%\begin{macro}{\squarekilometer}
-%\begin{macro}{\ar}
-%\begin{macro}{\hectar}
-% Areas, including the mis-spellings for \cs{are} and
-% \cs{hectare}.
+%\begin{macro}{\deca}
+%\begin{macro}{\deka}
+%\begin{macro}{\hecto}
+%\begin{macro}{\kilo}
+%\begin{macro}{\mega}
+%\begin{macro}{\giga}
+%\begin{macro}{\tera}
+%\begin{macro}{\peta}
+%\begin{macro}{\exa}
+%\begin{macro}{\zetta}
+%\begin{macro}{\yotta}
+% Now the large ones.
 %    \begin{macrocode}
-\newunit{\squaremeter}{\Square\meter}
-\newunit{\squarecentimeter}{\Square\centi\meter}
-\newunit{\squarekilometer}{\Square\kilo\meter}
-\newunit{\ar}{a}
-\newunit{\hectar}{\hecto\ar}
+\DeclareSIPrefix \deca  { da } { 1 }
+\DeclareSIPrefix \deka  { da } { 1 }
+\DeclareSIPrefix \hecto { h }  { 2 }
+\DeclareSIPrefix \kilo  { k }  { 3 }
+\DeclareSIPrefix \mega  { M }  { 6 }
+\DeclareSIPrefix \giga  { G }  { 9 }
+\DeclareSIPrefix \tera  { T }  { 12 }
+\DeclareSIPrefix \peta  { P }  { 15 }
+\DeclareSIPrefix \exa   { E }  { 18 }
+\DeclareSIPrefix \zetta { Z }  { 21 }
+\DeclareSIPrefix \yotta { Y }  { 24 }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\kv}
-%\begin{macro}{\mv}
-% The code for \unitsdef has the capitalisation wrong for \cs{kV} and
-% \cs{mV}.
-%    \begin{macrocode}
-\ifsi@old@noabbr
-\else
-  \ifsi@old@novoltageabbr\else
-    \newunit{\kv}{\kilo\volt}
-    \newunit{\mv}{\milli\volt}
-  \fi
-\fi
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\sek}
-%\begin{macro}{\fg}
-%\begin{macro}{\fl}
-%\begin{macro}{\pl}
-%\begin{macro}{\nl}
-%\begin{macro}{\micl}
-%\begin{macro}{\ml}
-%\begin{macro}{\cl}
-%\begin{macro}{\dl}
-%\begin{macro}{\hl}
-% There are some slightly different abbreviations, plus some which
-% are not officially allowed.
-%    \begin{macrocode}
-\ifsi@old@noabbr\else
-  \ifsi@old@notimeabbr\else
-    \newunit{\sek}{\second}
-  \fi
-  \ifsi@old@noweightabbr\else
-    \newunit{\fg}{\femto\gram}
-  \fi
-  \ifsi@old@novolumeabbr\else
-    \newunit{\fl}{\femto\liter}
-    \newunit{\pl}{\pico\liter}
-    \newunit{\nl}{\nano\liter}
-    \newunit{\micl}{\micro\liter}
-    \newunit{\ml}{\milli\liter}
-    \newunit{\cl}{\centi\liter}
-    \newunit{\dl}{\deci\liter}
-    \newunit{\hl}{\hecto\liter}
-  \fi
-\fi
-%    \end{macrocode}
-%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\becquerel}
+%\begin{macro}{\celsius}
+%\begin{macro}{\degreeCelsius}
+%\begin{macro}{\coulomb}
+%\begin{macro}{\farad}
+%\begin{macro}{\gray}
+%\begin{macro}{\hertz}
+%\begin{macro}{\henry}
+%\begin{macro}{\joule}
+%\begin{macro}{\katal}
+%\begin{macro}{\lumen}
+%\begin{macro}{\lux}
+% A number of derived units with defined names and symbols.
+%    \begin{macrocode}
+\DeclareSIUnit \becquerel     { Bq }
+\DeclareSIUnit \celsius       { \SIUnitSymbolCelsius }
+\DeclareSIUnit \degreeCelsius { \SIUnitSymbolCelsius }
+\DeclareSIUnit \coulomb       { C }
+\DeclareSIUnit \farad         { F }
+\DeclareSIUnit \gray          { Gy }
+\DeclareSIUnit \hertz         { Hz }
+\DeclareSIUnit \henry         { H }
+\DeclareSIUnit \joule         { J }
+\DeclareSIUnit \katal         { kat }
+\DeclareSIUnit \lumen         { lm }
+\DeclareSIUnit \lux           { lx }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\calory}
-%\begin{macro}{\kilocalory}
-% \unitsdef spells calorie incorrectly, and it is also not an SI unit.
-%    \begin{macrocode}
-\newunit{\calory}{cal}
-\newunit{\kilocalory}{\kilo\calory}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\uBar}
-% \unitsdef uses \cs{ubar} for bar.
-%    \begin{macrocode}
-\newunit{\uBar}{ba}
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\gensymbohm}
-%\begin{macro}{\gensymbcelsius}
-%\begin{macro}{\gensymbmicro}
-%\begin{macro}{\gensymbdegree}
-% If the options relating to \pkg{gensymb} are given, then the
-% package \emph{has} to be loaded.  The definitions are then renamed;
-% a slight awkward feature is that the hyphen character needs to be a
-% letter.  To avoid needing to worry about this again, a second
-% switch is set up.
-%    \begin{macrocode}
-\catcode`\-=11\relax
-\ifsi@old@redef-gensymb
-  \expandafter\si@gensymbtrue
-\fi
-\catcode`\-=12\relax
-\ifsi@gensymb
-  \RequirePackage{gensymb}
-  \AtBeginDocument{
-    \let\gensymbohm\ohm
-    \let\gensymbcelsius\celsius
-    \let\gensymbmicro\micro
-    \let\gensymbdegree\degree
-    \let\ohm\@undefined
-    \let\celsius\@undefined
-    \let\micro\@undefined
-    \let\degree\@undefined
-    \ifsi@old@OHM\else
-      \newunit{\ohm}{\si@sym@Omega}
-      \newunit{\celsius}{\si@sym@celsius}
-      \newprefix{\micro}{\si@sym@mu}{-6}
-      \newunit{\degree}{\si@sym@degree}
-    \fi}
-\fi
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-% The configuration files can now be loaded.
-%    \begin{macrocode}
-\requiresiconfigs{prefix,named,addn,accepted}
-%    \end{macrocode}
-% The \opt{noconfig} option could be ignored, but it costs little to
-% let is be used.
-%    \begin{macrocode}
-\ifsi@old@noconfig\else
-  \InputIfFileExists{unitsdef.cfg}
-    {\si@log@inf{unitsdef config file loaded}}
-    {\si@log@inf{unitsdef config file not found}}
-\fi
-%    \end{macrocode}
-%
-%\iffalse
-%</unitsdef>
-%<*sistyle>
-%\fi
-%\subsection{\SIstyle}
-% After setting the necessary defaults, the emulation code defines
-% the macros in \SIstyle as given in the manual for that package.
-%    \begin{macrocode}
-\ProvidesFile{si-sistyle.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     SIstyle]
-\si@emulating{sistyle}{2006/12/20 v2.3}
-\sisetup{%
-  sepfour=true,
-  obeyfamily,
-  obeyitalic=true,
-  numsign=+-,
-  strictarc=false,
-  unitsep=cdot}
-%    \end{macrocode}
-%\begin{macro}{\SIobeyboldtrue}
-%\begin{macro}{\SIobeyboldfalse}
-% Some simple switches, but not using \cs{newif}.
+%\begin{macro}{\newton}
+%\begin{macro}{\ohm}
+%\begin{macro}{\pascal}
+%\begin{macro}{\radian}
+%\begin{macro}{\siemens}
+%\begin{macro}{\sievert}
+%\begin{macro}{\steradian}
+%\begin{macro}{\tesla}
+%\begin{macro}{\volt}
+%\begin{macro}{\watt}
+%\begin{macro}{\weber}
+% More units.
 %    \begin{macrocode}
-\newcommand*{\SIobeyboldtrue}{\sisetup{obeybold=true}}
-\newcommand*{\SIobeyboldfalse}{\sisetup{obeybold=false}}
+\DeclareSIUnit \newton    { N }
+\DeclareSIUnit \ohm       { \SIUnitSymbolOhm }
+\DeclareSIUnit \pascal    { Pa }
+\DeclareSIUnit \radian    { rad }
+\DeclareSIUnit \siemens   { S }
+\DeclareSIUnit \sievert   { Sv }
+\DeclareSIUnit \steradian { sr }
+\DeclareSIUnit \tesla     { T }
+\DeclareSIUnit \volt      { V }
+\DeclareSIUnit \watt      { W }
+\DeclareSIUnit \weber     { Wb }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\num}
-%\begin{macro}{\si@sis@num}
-%\begin{macro}{\si@sis@numstar}
-% To get the correct behaviour for \cs{num}, some redefinitions are
-% needed to handle to optional |*|.
-%    \begin{macrocode}
-\let\num\relax
-\si@newrobustcmd*{\num}{%
-  \@ifstar
-    {\si@sis@numstar}
-    {\si@sis@num}}
-\newcommand*{\si@sis@num}[2][]{%
-  \begingroup%
-    \sisetup{#1}%
-    \expandafter\si@out@num\expandafter{\si@num{#2}}%
-  \endgroup}
-\newcommand*{\si@sis@numstar}[2][]{%
-  \begingroup%
-    \sisetup{mode=text,obeybold}%
-    \sisetup{#1}%
-    \expandafter\si@out@num\expandafter{\si@num{#2}}%
-  \endgroup}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\pnt}
-% The \cs{pnt} macro is needed as |.| is active inside \cs{SI}.  The
-% name is exactly the same as in \SIstyle, but the implementation is
-% different.  This is not defined by the main package as there are
-% better ways of including numbers in the output than this.
-%    \begin{macrocode}
-\newcommand*{\pnt}{\ensuremath{\si@decimalsymbol}}
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\SIgroupfourtrue}
-%\begin{macro}{\SIgroupfourfalse}
-% Switches for grouping four characters.
-%    \begin{macrocode}
-\newcommand*{\SIgroupfourtrue}{\sisetup{sepfour=true}}
-\newcommand*{\SIgroupfourfalse}{\sisetup{sepfour=false}}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\SIunitsep}
-%\begin{macro}{\SIunitspace}
-%\begin{macro}{\SIunitdot}
-% Whatever is given here is passed through to \cs{sisetup}.
-%    \begin{macrocode}
-\newcommand*{\SIunitsep}[1]{\sisetup{valuesep={#1}}}
-\newcommand*{\SIunitspace}[1]{\sisetup{unitspace={#1}}}
-\newcommand*{\SIunitdot}[1]{\sisetup{unitsep={#1}}}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\SIdecimalsymbol}
-%\begin{macro}{\SIthousandsep}
-%\begin{macro}{\SIproductsign}
-%\begin{macro}{\SIdecimalsign}
-% The same is true here, with the appropriate translation.
+%
+%\begin{macro}{\arcminute}
+%\begin{macro}{\arcsecond}
+%\begin{macro}{\day}
+%\begin{macro}{\degree}
+%\begin{macro}{\hectare}
+%\begin{macro}{\hour}
+%\begin{macro}{\litre}
+%\begin{macro}{\liter}
+%\begin{macro}{\minute}
+%\begin{macro}{\percent}
+%\begin{macro}{\tonne}
+% Non-SI, but accepted for general use.
 %    \begin{macrocode}
-\newcommand*{\SIdecimalsymbol}[1]{\sisetup{decimalsymbol={#1}}}
-\newcommand*{\SIthousandsep}[1]{\sisetup{digitsep={#1}}}
-\newcommand*{\SIproductsign}[1]{\sisetup{expproduct={#1}}}
-\newcommand*{\SIdecimalsign}[1]{\sisetup{decimalsymbol={#1}}}
+\DeclareSIUnitWithOptions \arcmin { \arcminute } 
+  { number-unit-separator = }
+\DeclareSIUnitWithOptions \arcminute { \SIUnitSymbolArcminute } 
+  { number-unit-separator = }
+\DeclareSIUnitWithOptions \arcsecond { \SIUnitSymbolArcsecond } 
+  { number-unit-separator = }
+\DeclareSIUnit \day { d }
+\DeclareSIUnitWithOptions \degree { \SIUnitSymbolDegree } 
+  { number-unit-separator = }
+\DeclareSIUnit \hectare { ha }
+\DeclareSIUnit \hour    { h }
+\DeclareSIUnit \litre   { l }
+\DeclareSIUnit \liter   { L }
+\DeclareSIUnit \minute  { min }
+\DeclareSIUnit \percent { \char 37 }
+\DeclareSIUnit \tonne   { t }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\si@sis@savefont}
-%\darg{setting}
-%\darg{argument}
-% The font definitions need a bit of extra work doing.  As both
-% settings here have |@| as a letter, all should be fine.
-%    \begin{macrocode}
-\newcommand*{\si@sis@savefont}[2]{%
-  \@namedef{si@sis@#1}{#2}%
-  \sisetup{#1=si@sis@#1}}
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\SImathrm}
-%\begin{macro}{\SImathsf}
-%\begin{macro}{\SImathtt}
-% The font control macros have to ensure that a macro name is passed
-% to \cs{sisetup}.
-%    \begin{macrocode}
-\newcommand*{\SImathrm}[1]{\si@sis@savefont{mathrm}{#1}}
-\newcommand*{\SImathsf}[1]{\si@sis@savefont{mathsf}{#1}}
-\newcommand*{\SImathtt}[1]{\si@sis@savefont{mathtt}{#1}}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\SIdefaultMfam}
-%\begin{macro}{\SIdefaultNfam}
-%\begin{macro}{\SIdefaultTfam}
-% The same for the default keys.
-%    \begin{macrocode}
-\newcommand*{\SIdefaultMfam}[1]{\si@sis@savefont{mathrm}{#1}}
-\newcommand*{\SIdefaultNfam}[1]{\si@sis@savefont{mathnumrm}{#1}}
-\newcommand*{\SIdefaultTfam}[1]{\si@sis@savefont{textrm}{#1}}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\ensureupmath}
-% The \cs{ensureupmath} command guarantees processing by the
-% font-matching system. The argument cannot be processed here, so
-% care is needed.
+%
+%\begin{macro}{\astronomicalunit}
+%\begin{macro}{\atomicmassunit}
+%\begin{macro}{\electronvolt}
+%\begin{macro}{\dalton}
+% A few units based on physical measurements exist.  
 %    \begin{macrocode}
-\si@newrobustcmd*{\ensureupmath}[1]{%
-  \begingroup
-    \sisetup{mode=maths,obeyitalic=false}%
-    \si@out{#1}%
-  \endgroup}
+\DeclareSIUnit \astronomicalunit { ua }
+\DeclareSIUnit \atomicmassunit   { u }
+\DeclareSIUnit \electronvolt     { eV }
+\DeclareSIUnit \dalton           { Da }
 %    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\degC}
-%\begin{macro}{\degF}
-%\begin{macro}{\arcdeg}
-% A few extra symbol names are needed.
-%    \begin{macrocode}
-\newcommand*{\degC}{\si@sym@celsius}
-\newcommand*{\arcdeg}{\si@sym@degree}
-\newcommand*{\degF}{\si@sym@degree F}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\begin{macro}{\clight}
+%\begin{macro}{\electronmass}
+%\begin{macro}{\planckbar}
+% A set of \enquote{natural units}.
+%    \begin{macrocode}
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \DeclareSIUnit \clight { \text { \ensuremath { c @ { 0 } } } }
+  \DeclareSIUnit \electronmass 
+    { \text { \ensuremath { m @ { \text { e } } } } } 
+}
+\DeclareSIUnit \planckbar { \text { \ensuremath { \hbar } } }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\AddToSIstyle}
-%\begin{macro}{\SIstyle}
-%\begin{macro}{\SIstyleToLang}
-%\begin{macro}{\si@sis@addtolocale}
-% Finally, the locale control.
+%\begin{macro}{\elementarycharge}
+%\begin{macro}{\bohr}
+%\begin{macro}{\hartree}
+% A set of \enquote{atomic units}.
 %    \begin{macrocode}
-\newcommand*{\SIstyle}[1]{\sisetup{locale=#1}}
-\newcommand*{\SIstyleToLang}[2]{\sisetup{loctolang=#1:#2}}
-\newcommand*{\AddToSIstyle}{%
-  \si@switchfalse
-  \@ifstar
-    {\si@switchtrue
-     \si@sis@addtolocale}
-    {\si@sis@addtolocale}}
-\newcommand*{\si@sis@addtolocale}[2]{%
-  \ifsi@switch
-    \expandafter\let\csname si@loc@#1@extra\endcsname\relax
-  \fi
-  \addtolocale{#1}{#2}}
+\DeclareSIUnit \elementarycharge { \text { \ensuremath { e } } }
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \DeclareSIUnit \bohr { \text { \ensuremath { a @ { 0 } } } }
+  \DeclareSIUnit \hartree 
+    { \text { \ensuremath { E @ { \textup { h } } } } }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\end{macro}
 %
-%\iffalse
-%</sistyle>
-%<*SIunits>
-%\fi
-%\subsection{\SIunits}
-% \SIunits emulation starts in much the same way.
-%    \begin{macrocode}
-\ProvidesFile{si-SIunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     SIunits]
-\si@emulating{SIunits}{2007/12/02 v1.36}
-\sisetup{
-  unitsep=thick,
-  valuesep=thick,
-  prefixproduct=\si@valuesep,
-  trapambigfrac=false,
-  stickyper}
-\requiresiconfigs{prefix,named,accepted,physical}
-%    \end{macrocode}
-%\begin{macro}{\reciprocal}
-%\begin{macro}{\rp}
-%\begin{macro}{\per}
-%\begin{macro}{\usk}
-%\begin{macro}{\power}
-%\begin{macro}{\rpsquare}
-%\begin{macro}{\rpcubic}
-%\begin{macro}{\fourth}
-%\begin{macro}{\rpfourth}
-% A few very simple translations, using the internal version of
-% \cs{per} to allow changes of output style.
+%\begin{macro}{\angstrom}
+%\begin{macro}{\bar}
+%\begin{macro}{\barn}
+%\begin{macro}{\bel}
+%\begin{macro}{\decibel}
+%\begin{macro}{\knot}
+%\begin{macro}{\mmHg}
+%\begin{macro}{\nauticalmile}
+%\begin{macro}{\neper}
+% There are then some day-to-day units which are accepted for use
+% with SI, but are not part of the official specification.
 %    \begin{macrocode}
-\newcommand*{\reciprocal}{\sisetup{per=reciprocal}\si@per}
-\let\rp\reciprocal
-\renewcommand*{\per}{\sisetup{per=slash}\si@per}
-\newcommand*{\usk}{}
-\newcommand*{\power}[1]{#1\tothe}
-\newcommand*{\rpsquare}{\sisetup{per=reciprocal}\si@per\Square}
-\newcommand*{\rpcubic}{\sisetup{per=reciprocal}\si@per\cubic}
-\newpower{\fourth}{4}
-\newcommand*{\rpfourth}{\sisetup{per=reciprocal}\si@per\fourth}
+\DeclareSIUnit \angstrom     { \SIUnitSymbolAngstrom }
+\DeclareSIUnit \bar          { bar }
+\DeclareSIUnit \barn         { b }
+\DeclareSIUnit \bel          { B }
+\DeclareSIUnit \decibel      { \deci \bel }
+\DeclareSIUnit \knot         { kn }
+\DeclareSIUnit \mmHg         { mmHg }
+\DeclareSIUnit \nauticalmile { M }
+\DeclareSIUnit \neper        { Np }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -12761,415 +12515,839 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%\end{macro} 
+%\end{macro} 
+%\end{macro} 
+%
+%\begin{macro}{\square}
+%\begin{macro}{\squared}
+%\begin{macro}{\cubic}
+%\begin{macro}{\cubed}
+% The basic powers are also defined.
+%    \begin{macrocode}
+\DeclareSIPrePower  \square  { 2 }
+\DeclareSIPostPower \squared { 2 }
+\DeclareSIPrePower  \cubic   { 3 }
+\DeclareSIPostPower \cubed   { 3 }
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\rpsquared}
-%\begin{macro}{\rpcubed}
-% Here, some low-level switch changing is needed.
+%
+%\subsection{Odds and ends}
+%  
+%\begin{macro}{\requiresiconfigs}
+%\begin{macro}{\_siunitx_requireconfig:n}
+% Version one provides this, and it might pop up so should not 
+% cause errors.
 %    \begin{macrocode}
-\newcommand*{\rpsquared}{%
-  \sisetup{per=reciprocal}\si@unt@pertrue\si@unt@perseentrue%
-    \squared}
-\newcommand*{\rpcubed}{%
-  \sisetup{per=reciprocal}\si@unt@pertrue\cubed}
+\NewDocumentCommand \requiresiconfigs { m } {
+  \keys_set:nn { siunitx } { load-configurations = version-1 }
+  \clist_map_function:nN {#1} \_siunitx_requireconfig:n
+}
+\cs_set_protected_nopar:Npn \_siunitx_requireconfig:n #1 {
+  \tl_if_eq:nnT {#1} { synchem }
+    { \keys_set:nn { siunitx } { load-configurations = chemistry } }
+}
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\SIsetup}
-%\begin{macro}{\si@siu@setup}
-% The various package spacing options are processed.  They also have
-% to be correctly handled by the \cs{SIsetup} macro.
+%
+%\subsection{Strict application of the rules}
+%
+%\begin{macro}{\_siunitx_strict_option:n}
+%\begin{macro}[aux]{\_siunitx_strict_option_aux:n}
+% When sticking to the rules closely, a few options are not available.
+%    \begin{macrocode}
+\keys_define:nn { siunitx } {
+  strict .code:n = 
+    {
+      \keys_set:nn { siunitx } 
+        {
+          bracket-numbers       = true,
+          detect-italic         = false,
+          detect-mode           = false,
+          detect-weight         = false,
+          multi-part-units      = bracket,
+          parse-numbers         = true,
+          parse-units           = true,
+          product-units         = repeat,
+        }
+      \_siunitx_strict_option:n  
+        { 
+          bracket-numbers       ,
+          detect-italic         ,
+          detect-mode           ,
+          detect-weight         ,
+          multi-part-units      ,
+          parse-numbers         ,
+          parse-units           ,
+          product-units         ,
+        }
+      \keys_define:nn { siunitx }
+        {
+          per-mode / repeated-symbol .code:n =
+            { 
+              \msg_warning:nnx { siunitx } { option-not-available } 
+                {  per-mode~=~repeated-symbol }
+            }
+        }  
+    }
+}
+\_siunitx_option_deactivate:n { strict }
+\cs_set_protected_nopar:Npn \_siunitx_strict_option:n #1 {
+  \clist_map_function:nN {#1} \_siunitx_strict_option_aux:n 
+}
+\cs_set_protected_nopar:Npn \_siunitx_strict_option_aux:n #1 {
+  \keys_define:nn { siunitx }
+    { #1 .code:n = 
+      { \msg_warning:nnx { _siunitx} { option-not-available } {#1} }
+    }  
+}
+%    \end{macrocode}
+%\end{macro}    
+%\end{macro} 
+%
+%\subsection{Loading additional configurations}
+%
+% There is only only option for loading files: keeps things simple.
 %    \begin{macrocode}
-\newcommand*{\SIsetup}[1]{%
-  \@for\si@tempa:=#1\do{%
-    \@ifundefined{ifsi@old@#1}
-      {\si@log@warn{Unknown SIunits option `#1'}}
-      {\csname si@old@#1true\endcsname}}
-  \si@siu@setup}
-\newcommand*{\si@siu@setup}{%
-  \ifsi@old@cdot
-    \sisetup{unitsep=cdot}%
-  \fi
-  \ifsi@old@thickspace
-    \sisetup{unitsep=thick}%
-  \fi
-  \ifsi@old@mediumspace
-    \sisetup{unitsep=medium}%
-  \fi
-  \ifsi@old@thinspace
-    \sisetup{unitsep=thin}%
-  \fi
-  \ifsi@old@thickqspace
-    \sisetup{valuesep=thick}%
-  \fi
-  \ifsi@old@mediumqspace
-    \sisetup{valuesep=medium}%
-  \fi
-  \ifsi@old@thinqspace
-    \sisetup{valuesep=thin}%
-  \fi}
-\si@siu@setup
+\keys_define:nn { siunitx } {
+  load-configurations .code:n =
+    { \_siunitx_load_configuration:n {#1} }
+}
 %    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\square}
-%\begin{macro}{\squaren}
-% \SIunits does slightly different things about the clash with
-% \cs{square}, and either redefines this macro or provides
-% \cs{squaren}.
+%    
+%\begin{macro}{\_siunitx_load_configuration:n}
+%\begin{macro}[aux]{\_siunitx_load_configuration_aux:n}
+%\begin{macro}{\_c_siunitx_configuration_ext_tl}
+% Loading configuration files is made slightly complex by the need
+% to remove spaces in the file names (none of the files contain any at
+% all, so this is easy). Secondly, the LaTeX2e \cs{@onefilewithoptions}
+% function is used for file loading, as LaTeX3 currently needs the
+% LaTeX2e category code stack to keep things sane.
+%    \begin{macrocode}
+\cs_set_protected:Npn \_siunitx_load_configuration:n #1 {
+  \tl_set_rescan:Nnn \_l_siunitx_tmpa_tl
+    { \char_make_ignore:N \ } {#1}
+  \clist_map_function:NN \_l_siunitx_tmpa_tl 
+    \_siunitx_load_configuration_aux:n
+}
+\cs_set_protected:Npn \_siunitx_load_configuration_aux:n #1 {
+  \tl_if_empty:nF {#1}
+    {
+      \file_if_exist:nTF 
+        { siunitx- #1 . \_c_siunitx_configuration_ext_tl }
+        { 
+          \@onefilewithoptions { siunitx- #1 } [ ] [ ] 
+          \_c_siunitx_configuration_ext_tl  
+        }
+        { 
+          \msg_error:nnx { siunitx } { unknown-configuration-file } {#1}
+        }
+    }
+}
+\tl_new:N \_c_siunitx_configuration_ext_tl
+\tl_set:Nn \_c_siunitx_configuration_ext_tl { cfg }
+%    \end{macrocode}
+%\end{macro}    
+%\end{macro} 
+%\end{macro} 
+% 
+% Load any local configuration file.  
 %    \begin{macrocode}
-\ifsi@old@squaren
-  \newpower{\squaren}{2}
-\fi
-\AtBeginDocument{%
-  \@ifundefined{square}
-    {\newpower{\square}{2}}
-    {\ifsi@old@amssymb
-       \renewpower{\square}{2}
-     \else
-       \ifsi@old@squaren\else
-         \si@log@warn{\string\square\space already
-           defined\MessageBreak SIunits mode may cause
-           errors}%
-       \fi
-     \fi}}
+\file_if_exist:nT { siunitx . \_c_siunitx_configuration_ext_tl }
+  { 
+    \@onefilewithoptions { siunitx } [ ] [ ]
+      \_c_siunitx_configuration_ext_tl  
+  }
 %    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\gray}
-% The potential clash with \pkg{PStricks} is also handled
-% differently; here, \cs{Gray} will already be defined by the
-%  \currpkg kernel.
-%    \begin{macrocode}
-\AtBeginDocument{
-  \@ifundefined{gray}
-    {\newunit{\gray}{Gy}}
-    {\ifsi@old@pstricks
-       \renewunit{\gray}{Gy}
-     \else
-       \ifsi@old@Gray\else
-         \si@log@warn{\string\gray\space already
-           defined\MessageBreak SIunits mode may cause
-           errors}%
-       \fi
-     \fi}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\unit}
-%\begin{macro}{\unita}
-% The \cs{unit} macro is defined.
-%    \begin{macrocode}
-\ifsi@old@italian
-  \let\unita\SI
-\else
-  \let\unit\SI
-\fi
+%
+% Finally apply the settings given at load time.
+%    \begin{macrocode}
+\ProcessKeysOptions { siunitx }
 %    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% The miscellaneous options are moped up.
+%    
 %    \begin{macrocode}
-\ifsi@old@textstyle
-  \sisetup{mode=text}
-\fi
-\ifsi@old@binary
-  \sisetup{alsoload=binary}
-\fi
+%</package>
 %    \end{macrocode}
-%\begin{macro}{\arcminute}
-%\begin{macro}{\arcsecond}
-%\begin{macro}{\rperminute}
-%\begin{macro}{\ton}
-%\begin{macro}{\degreecelsius}
-% The unit macros defined by \SIunits that are not defined by
-% \currpkg (by default).
-%    \begin{macrocode}
-\newunit[valuesep=none]{\arcminute}{\si@sym@minute}
-\newunit[valuesep=none]{\arcsecond}{\si@sym@second}
-\newunit{\rperminute}{r/min}
-\newunit{\ton}{t}
-\newunit{\degreecelsius}{\celsius}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-%\begin{macro}{\addunit}
-% This is an alias for \cs{newunit}.
-%    \begin{macrocode}
-\let\addunit\newunit
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\addprefix}
-% A little more work for \cs{addprefix}.
-%    \begin{macrocode}
-\newcommand*{\addprefix}[2]{\newprefix{#1}{#2}}
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\si@siu@newunit}
-%\changes{v1.1a}{2008/09/30}{Corrected very minor bug in definition}
-%\begin{macro}{\si@siu@power}
-%\begin{macro}{\si@siu@newunithook}
-%\doarg{power}
-%\darg{numerator}
-%\darg{denominator}
-% To save some code, making new units which need a \texttt{\ldots np}
-% variant is handled by a dedicated macro.
-%    \begin{macrocode}
-\newcommand*{\si@siu@newunit}[3][]{%
-%    \end{macrocode}
-% A test is needed to sort out \cs{square}.
-%    \begin{macrocode}
-  \renewcommand*{\si@tempa}{#1}%
-  \renewcommand*{\si@tempb}{square}%
-  \def\si@siu@power{}%
-  \ifx\@empty\si@tempa\@empty\else
-    \ifx\si@tempa\si@tempb
-      \renewcommand*{\si@siu@power}{\ssquare}%
-    \else
-      \edef\si@siu@power{%
-        \expandafter\noexpand\csname #1\endcsname}%
-    \fi
-  \fi
-%    \end{macrocode}
-% The necessary information is now stored in temporary macros.
-%    \begin{macrocode}
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3\endcsname}%
-  \edef\si@tempb{%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\per
-    \expandafter\noexpand\si@siu@power
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter%
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempb}
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3np\endcsname}%
-  \edef\si@tempb{%
-    \expandafter\noexpand\csname #2\endcsname\noexpand
-    \reciprocal\expandafter\noexpand\si@siu@power
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempb}%
-  \si@siu@newunithook[#1]{#2}{#3}}
-\providecommand*{\si@siu@newunithook}[3][]{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-%\end{macro}
-% The basic units are now defined; these only have a single csname in
-% each of the numerator and denominator.
-%    \begin{macrocode}
-\si@siu@newunit{gray}{second}
-\si@siu@newunit[square]{metre}{second}
-\si@siu@newunit{joule}{mole}
-\si@siu@newunit[cubic]{mole}{metre}
-\si@siu@newunit[square]{radian}{second}
-\si@siu@newunit{radian}{second}
-\si@siu@newunit[cubic]{squaremetre}{metre}
-\si@siu@newunit[cubic]{katal}{metre}
-\si@siu@newunit{coulomb}{mol}
-\si@siu@newunit[square]{ampere}{metre}
-\si@siu@newunit[cubic]{kilogram}{metre}
-\si@siu@newunit[cubic]{coulomb}{metre}
-\si@siu@newunit{volt}{metre}
-\si@siu@newunit[square]{coulomb}{squaremetre}
-\si@siu@newunit{farad}{metre}
-\si@siu@newunit[square]{watt}{metre}
-\si@siu@newunit[square]{joule}{metre}
-\si@siu@newunit[cubic]{newton}{metre}
-\si@siu@newunit{newton}{kilogram}
-\si@siu@newunit{joule}{kelvin}
-\si@siu@newunit{joule}{kilogram}
-\si@siu@newunit{coulomb}{kilogram}
-\si@siu@newunit{squaremetre}{second}
-\si@siu@newunit[square]{squaremetre}{second}
-\si@siu@newunit[square]{candela}{metre}
-\si@siu@newunit{ampere}{metre}
-\si@siu@newunit{joule}{tesla}
-\si@siu@newunit{henry}{metre}
-\si@siu@newunit{kilogram}{second}
-\si@siu@newunit[square]{kilogram}{metre}
-\si@siu@newunit{kilogram}{metre}
-\si@siu@newunit[square]{newton}{metre}
-\si@siu@newunit{watt}{kilogram}
-\si@siu@newunit[cubic]{watt}{metre}
-\si@siu@newunit{squaremetre}{kilogram}
-\si@siu@newunit{cubicmetre}{kilogram}
-\si@siu@newunit{newton}{metre}
-\si@siu@newunit[cubic]{squaremetre}{second}
-\si@siu@newunit{metre}{second}
-\si@siu@newunit[cubic]{joule}{metre}
-\si@siu@newunit{cubicmetre}{second}
-%    \end{macrocode}
-%\begin{macro}{\si@siu@newunitx}
-%\begin{macro}{\si@siu@newunitxhook}
-% For the more complex units, a slightly different approach is used;
-% four arguments are required, and have to cover everything.
-%    \begin{macrocode}
-\newcommand*{\si@siu@newunitx}[4]{%
-  \expandafter\newunit\expandafter{\csname #1per#2\endcsname}
-    {#3\per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2np\endcsname}
-    {#3\reciprocal#4}
-  \si@siu@newunitxhook{#1}{#2}{#3}{#4}}
-\providecommand*{\si@siu@newunitxhook}[4]{}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% The units are defined.
-%    \begin{macrocode}
-\si@siu@newunitx{kilogramsquaremetre}{second}
-  {\kilogram\squaremetre}{\second}
-\si@siu@newunitx{squaremetre}{newtonsecond}{\squaremetre}
-  {\newton\second}
-\si@siu@newunitx{kilogrammetre}{second}{\kilogram\metre}
-  {\second}
-\si@siu@newunitx{kilogram}{squaremetresecond}{\kilogram}
-  {\squaremetre\second}
-\si@siu@newunitx{joule}{molekelvin}{\joule}{\mole\kelvin}
-\si@siu@newunitx{kilogram}{kilomole}{\kilogram}{\kilo\mole}
-\si@siu@newunitx{kilogrammetre}{squaresecond}{\kilogram\metre}
-  {\second\squared}
-\si@siu@newunitx{watt}{squaremetresteradian}{\watt}
-  {\squaremetre\steradian}
-\si@siu@newunitx{joule}{kilogramkelvin}{\joule}
-  {\kilogram\kelvin}
-\si@siu@newunitx{watt}{metrekelvin}{\watt}{\metre\kelvin}
-\si@siu@newunitx{kilogram}{cubicmetrecoulomb}{\kilogram}
-  {\cubic\metre\coulomb}
-\si@siu@newunitx{kilogram}{secondcubicmetre}{\kilogram}
-  {\second\cubicmetre}
-%    \end{macrocode}
-%\begin{macro}{\si@siu@unity}
-% A bit of cleverness to get the ``1'' correct; to avoid any clash, the unit
-% is given an internal name.
-%    \begin{macrocode}
-\newunit{\si@siu@unity}{1}
-\si@siu@newunitx{}{squaremetresecond}{\si@siu@unity}
-  {\squaremetre\second}
-%    \end{macrocode}
-%\end{macro}
-% A few compound units that are best defined directly.
-%    \begin{macrocode}
-\newunit{\pascalsecond}{\pascal\second}
-\newunit{\amperemetresecond}{\ampere\metre\second}
-\newunit{\ohmmetre}{\ohm\metre}
-\newunit{\newtonmetre}{\newton\metre}
-\let\newtonmetrenp\newtonmetre
-\newunit{\kilogramsquaremetre}{\kilogram\squaremetre}
-\let\kilogramsquaremetrenp\kilogramsquaremetre
-%    \end{macrocode}
-%\begin{macro}{\si@siu@newprefix}
-%\darg{prefix}
-% To generate the prefixes correctly, a small saving in repetition.
-%    \begin{macrocode}
-\newcommand*{\si@siu@newprefix}[1]{%
-  \edef\si@tempa{\expandafter\noexpand\csname #1d\endcsname}%
-  \edef\si@tempb{\expandafter\noexpand\csname #1\endcsname}%
-  \expandafter\expandafter\expandafter\newcommand\expandafter
-    \expandafter\expandafter*\expandafter\expandafter
-    \expandafter{\expandafter\si@tempa\expandafter}\expandafter
-      {\expandafter\si@prefixsymbolicfalse\si@tempb}}
-%    \end{macrocode}
-%\end{macro}
-% This is now implemented.
-%    \begin{macrocode}
-\si@siu@newprefix{yocto}
-\si@siu@newprefix{zepto}
-\si@siu@newprefix{atto}
-\si@siu@newprefix{femto}
-\si@siu@newprefix{pico}
-\si@siu@newprefix{nano}
-\si@siu@newprefix{micro}
-\si@siu@newprefix{milli}
-\si@siu@newprefix{centi}
-\si@siu@newprefix{deca}
-\si@siu@newprefix{deka}
-\si@siu@newprefix{hecto}
-\si@siu@newprefix{kilo}
-\si@siu@newprefix{mega}
-\si@siu@newprefix{giga}
-\si@siu@newprefix{tera}
-\si@siu@newprefix{peta}
-\si@siu@newprefix{exa}
-\si@siu@newprefix{zetta}
-\si@siu@newprefix{yotta}
-\ifsi@old@binary
-  \si@siu@newprefix{kibi}
-  \si@siu@newprefix{mebi}
-  \si@siu@newprefix{gibi}
-  \si@siu@newprefix{tebi}
-  \si@siu@newprefix{pebi}
-  \si@siu@newprefix{exbi}
-\fi
+%
+%\subsection{Support for version one}
+%
+%    \begin{macrocode}
+%<*version-1> 
 %    \end{macrocode}
-%\begin{macro}{\derradian}
-%\begin{macro}{\dersteradian}
-%\begin{macro}{\derhertz}
-%\begin{macro}{\dernewton}
-%\begin{macro}{\derpascal}
-%\begin{macro}{\derjoule}
-%\begin{macro}{\derwatt}
-%\begin{macro}{\dercoulomb}
-%\begin{macro}{\dervolt}
-%\begin{macro}{\derfarad}
-%\begin{macro}{\derohm}
-% The derived units may need to be defined.
+%    
 %    \begin{macrocode}
-\ifsi@old@derived
-  \newunit{\derradian}{\metre\reciprocal\metre}
-  \newunit{\dersteradian}{\squaremetre\rpsquare\metre}
-  \newunit{\derhertz}{\reciprocal\second}
-  \newunit{\dernewton}{\metre\kilogram\second\rpsquared}
-  \newunit{\derpascal}{\newton\rpsquare\metre}
-  \newunit{\derjoule}{\newton\metre}
-  \newunit{\derwatt}{\joule\reciprocal\second}
-  \newunit{\dercoulomb}{\ampere\second}
-  \newunit{\dervolt}{\watt\reciprocal\ampere}
-  \newunit{\derfarad}{\coulomb\reciprocal\volt}
-  \newunit{\derohm}{\volt\reciprocal\ampere}
+\ProvidesExplFile {siunitx-version-1.cfg} {2010/05/23} {2.0} 
+  {siunitx: Version 1 settings}
+%    \end{macrocode}
+%    
+% The abbreviations are loaded by default be version one.   
+%    \begin{macrocode}
+\keys_set:nn { siunitx } { load-configurations = abbreviations }
+%    \end{macrocode}
+%
+% The re-arrangements made to the code in version two, and in particular
+% the new option names, mean that support for version one needs to be
+% included explicitly. 
+% 
+%    \begin{macrocode}   
+\keys_define:nn { siunitx } {
+  addsign        .choice: ,
+  addsign / 
+    false        .meta:n    = { explicit-sign           =             },
+  addsign /
+    true         .meta:n    = { explicit-sign           = +           },
+  addsign        .default:n = { true                                  },  
+  allowlitunits  .meta:n    = { free-standing-units     = #1          },
+  allowlitunits  .default:n = { true                                  },
+  allowoptarg    .meta:n    = { unit-optional-argument  = #1          },
+  allowoptargs   .default:n = { true                                  },
+  allowzeroexp   .meta:n    = { retain-zero-exponent    = #1          },
+  allowzeroexp   .default:n = { true                                  },
+%  angformat & List & Conversion of angle format \\
+  angelsep       .choice: ,
+  angelsep / 
+    cdot         .meta:n    = 
+      { arc-separator         = { } \cdot { }                         },
+  angelsep / 
+    comma        .meta:n    = { arc-separator           = { {,} }     },
+  angelsep / 
+    fullstop     .meta:n    = { arc-separator           = { { . } }   },
+  angelsep / 
+    med          .meta:n    = { arc-separator           = \:          },
+  angelsep / 
+    medium       .meta:n    = { arc-separator           = \:          },
+  angelsep / 
+    none         .meta:n    = { arc-separator           =             },
+  angelsep / 
+    period       .meta:n    = { arc-separator           = { { . } }   },
+  angelsep / 
+    space        .meta:n    = { arc-separator           = \text { ~ } },
+  angelsep / 
+    stop         .meta:n    = { arc-separator           = { { . } }   },
+  angelsep / 
+    thick        .meta:n    = { arc-separator           = \;          },
+  angelsep / 
+    thin         .meta:n    = { arc-separator           = \,          },
+  angelsep / 
+    tightcdot    .meta:n    = 
+      { arc-separator           = \bgroup \cdot \egroup               },
+  angelsep / 
+    tighttimes   .meta:n    =
+      { arc-separator           = \bgroup \times \egroup              },
+  angelsep / 
+    times        .meta:n    = { arc-separator           = \times      },
+  angelsep / 
+    unknown      .meta:n    = { arc-separator           = #1          },
+  astroang       .meta:n    = 
+    { angle-symbol-over-decimal = #1                                  },
+  astroang       .default:n = { true                                  },     
+  closeerr       .meta:n    = { close-bracket           = #1          },
+  closefrac      .meta:n    = { close-bracket           = #1          },
+  closerange     .meta:n    = { close-bracket           = #1          },
+  colorall       .code:n    = ,
+  colourall      .code:n    = ,
+  colorneg       .code:n    = ,
+  colourneg      .code:n    = ,
+  colorunits     .meta:n    = ,
+  colourunits    .meta:n    = ,
+  colorvalues    .meta:n    = ,
+  colourvalues   .meta:n    = ,
+  decimalsymbol  .choice: ,
+  decimalsymbol /
+    cdot         .meta:n    = 
+      { output-decimal-marker   = { } \cdot { }                       }, 
+  decimalsymbol 
+    fullstop     .meta:n    = { output-decimal-marker   = { { . } }   }, 
+  decimalsymbol /
+    period       .meta:n    = { output-decimal-marker   = { { . } }   },
+  decimalsymbol /
+    stop         .meta:n    = { output-decimal-marker   = { { . } }   },
+  decimalsymbol /
+    tightcdot    .code:n    = 
+      { output-decimal-marker   = \bgroup \cdot \egroup               },
+  decimalsymbol /
+    unknown      .meta:n    = { output-decimal-marker   = #1          },
+  debug          .code:n    = ,
+  detectdisplay  .meta:n    = { detect-display-math     = #1          },
+  detectdisplay  .default:n = { true                                  },
+  digitsep       .choice: ,
+  digitsep / 
+    cdot         .meta:n    = 
+      { group-separator       = { } \cdot { }                         },
+  digitsep / 
+    comma        .meta:n    = { group-separator         = { , }       },
+  digitsep / 
+    fullstop     .meta:n    = { group-separator         = .           },
+  digitsep / 
+    med          .meta:n    = { group-separator         = \:          },
+  digitsep / 
+    medium       .meta:n    = { group-separator         = \:          },
+  digitsep / 
+    none         .meta:n    = { group-separator         =             },
+  digitsep / 
+    period       .meta:n    = { group-separator         = .           },
+  digitsep / 
+    space        .meta:n    = { group-separator         = \text { ~ } },
+  digitsep / 
+    stop         .meta:n    = { group-separator         = .           },
+  digitsep / 
+    thick        .meta:n    = { group-separator         = \;          },
+  digitsep / 
+    thin         .meta:n    = { group-separator         = \,          },
+  digitsep / 
+    tightcdot    .meta:n    = 
+      { group-separator         = \bgroup \cdot \egroup               },
+  digitsep / 
+    tighttimes  .meta:n     =
+      { group-separator         = \bgroup \times \egroup              },
+  digitsep / 
+    times        .meta:n    = { group-separator         = \times      },
+  digitsep / 
+    unknown      .meta:n    = { group-separator         = #1          },
+  dp             .meta:n    = 
+    { 
+      round-mode      = places,
+      round-precision = #1,
+    },
+  emulate        .code:n    = ,
+  errspace       .choice: ,
+  errspace / 
+    med          .meta:n    = { uncertainty-separator   = \:          },
+  errspace / 
+    medium       .meta:n    = { uncertainty-separator   = \:          },
+  errspace / 
+    none         .meta:n    = { uncertainty-separator   =             },
+  errspace / 
+    space        .meta:n    = { uncertainty-separator   = \text { ~ } },
+  errspace / 
+    thick        .meta:n    = { uncertainty-separator   = \;          },
+  errspace / 
+    thin         .meta:n    = { uncertainty-separator   = \,          },
+  errspace / 
+    unknown      .meta:n    = { uncertainty-separator   = #1          },
+  eVcorra        .code:n    = ,
+  eVcorrb        .code:n    = ,
+  expbase        .choice: ,
+  expbase /
+    ten          .meta:n    = { exponent-base           = 10          },
+  expbase /
+    two          .meta:n    = { exponent-base           = 2           }, 
+  expbase /
+    unknown      .meta:n    = { exponent-base           = #1          }, 
+  expproduct / 
+    cdot         .meta:n    = 
+      { exponent-product        = { } \cdot { }                       },
+  expproduct / 
+    tightcdot    .meta:n    = 
+      { exponent-product        = \bgroup \cdot \egroup                },
+  expproduct / 
+    tighttimes   .meta:n    =
+      { exponent-product        = \bgroup \times \egroup             },
+  expproduct / 
+    times        .meta:n    = { exponent-product        = \times     },
+  expproduct /
+    unknown      .meta:n    = { exponent-product        = #1         },   
+  fixdp .choice:,
+  fixdp / 
+    false        .meta:n    = { round-mode              = none        },
+  fixdp / 
+    true         .meta:n    = { round-mode              = places      },
+  fixdp          .default:n = { true                                  },
+  fixsf          .choice: ,
+  fixsf / 
+    false        .meta:n    = { round-mode              = none        },
+  fixsf / 
+    true         .meta:n    = { round-mode              = figures     },
+  fixsf          .default:n = { true                                  },
+  fraction       .choice: ,
+  fraction /
+    frac         .meta:n    = { fraction-function       = \frac       },
+  fraction /
+    nice         .meta:n    = { fraction-function       = \frac       },
+  fraction /
+    sfrac        .meta:n    = { fraction-function       = \sfrac      },
+  fraction /
+    ugly         .meta:n    = 
+      { 
+        fraction-function       = \frac ,
+        per-mode                = symbol-or-fraction
+      },
+  inlinebold     .meta:n    = { detect-inline-weight    = #1          },
+  log            .code:n    = ,
+  load           .code:n    = ,
+  mathOmega      .meta:n    = { math-ohm                = #1          },
+  mathcelsius    .meta:n    = { math-celsius            = #1          },
+  mathdegree     .meta:n    = { math-degree             = #1          },
+  mathminute     .meta:n    = { math-arcminute          = #1          },
+  mathmu         .meta:n    = { math-micro              = #1          },
+  mathringA      .meta:n    = { math-angstrom           = #1          },
+  mathrm         .meta:x    = 
+    { math-rm                 = \exp_not:c {#1}                       },
+  mathsOmega     .meta:n    = { math-ohm                = #1          },
+  mathscelsius   .meta:n    = { math-celsius    .       = #1          },
+  mathsdegree    .meta:n    = { math-degree     .       = #1          },
+  mathsecond     .meta:n    = { math-arcsecond          = #1          },
+  mathsf         .meta:x    = 
+    { math-sf                 = \exp_not:c {#1}                       },
+  mathsminute    .meta:n    = { math-arcminute          = #1          },
+  mathsmu        .meta:n    = { math-micro              = #1          },
+  mathsringA     .meta:n    = { math-angstrom           = #1          },
+  mathsrm        .meta:x    = 
+    { math-rm                 = \exp_not:c {#1}                       },
+  mathssecond    .meta:n    = { math-arcsecond          = #1          },
+  mathssf        .meta:x    = 
+    { math-sf                 = \exp_not:c {#1}                       },
+  mathstt        .meta:x    = 
+    { math-tt                 = \exp_not:c {#1}                       },
+  mathtt         .meta:x    = 
+    { math-tt                 = \exp_not:c {#1}                       },
+  negcolor       .meta:n    = { negative-color          = #1          },
+  negcolour      .meta:n    = { negative-color          = #1          },
+  noload         .code:n    = ,
+  numaddn        .meta:n    = { input-symbols           = #1          },
+  numcloseerr    .meta:n    = { input-close-uncertainty = #1          },
+  numdecimal     .meta:n    = { input-decimal-markers   = #1          },
+  numdigits      .meta:n    = { input-digits            = #1          },
+  numdiv         .meta:n    = { input-quotient          = #1          },
+  numexp         .meta:n    = { input-exponent-markers  = #1          },
+  numgobble      .meta:n    = { input-ignore            = #1          },
+  numopenerr     .meta:n    = { input-open-uncertainty  = #1          },
+  numprod        .meta:n    = { input-product           = #1          },
+  numsign        .meta:n    = { input-signs             = #1          },
+  obeyall        .meta:n    = { detect-all              = #1          },
+  obeyall        .default:n = { true                                  },
+  obeybold       .meta:n    = { detect-weight           = #1          },
+  obeybold       .default:n = { true                                  },
+  obeyitalic     .meta:n    = { detect-italic           = #1          },
+  opbeyitalic    .default:n = { true                                  },
+  obeymode       .meta:n    = { detect-mode             = #1          },
+  obeymode       .default:n = { true                                  },
+  openerr        .meta:n    = { open-bracket            = #1          },
+  openfrac       .meta:n    = { open-bracket            = #1          },
+  openrange      .meta:n    = { open-bracket            = #1          },
+  padangle       .choice: ,
+  padangle /
+    all          .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+    both         .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+  padangle /
+    false        .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = false,
+        add-arc-second-zero = false
+      },
+  padangle /
+    large        .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = false
+      },
+  padangle /
+    none         .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = false,
+        add-arc-second-zero = false
+      },
+  padangle /
+    small         .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+    true         .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+  padnumber      .choice: ,
+  padnumber /
+    all          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  padnumber /
+    both          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  padnumber /
+    false         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = false
+      },
+  padnumber /
+    leading        .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = false
+      },
+  padnumber /
+    none         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = false
+      },
+  padnumber /
+    trailing         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = true
+      },
+  padnumber /
+    true          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  per           .choice: ,
+  per /
+    fraction     .meta:n    = { per-mode                = fraction    },
+  per / 
+    reciprocal   .meta:n    = { per-mode                = reciprocal  },
+  per /
+    slash        .meta:n    = { per-mode                = symbol      },
+  prefixbase     .code:n    = ,
+  prefixproduct  .code:n    = ,
+  prefixsymbolic .meta:n    = { prefixes-as-symbols     = #1          },
+  prefixsymbolic .default:n = { true                                  },
+  prespace       .meta:n    = { space-before-unit       = #1          },
+  prespace       .default:n = { true                                  },
+  redefsymbols   .meta:n    = { redefine-symbols        = #1          },
+  redefsymbols   .default:n = { true                                  },
+  repeatunits    .choice: ,
+  repeatunits /
+    false        .meta:n    = 
+      { 
+        multi-part-numbers    = single,
+        product-units         = single,                  
+      },
+  repeatunits /
+    power        .meta:n    = 
+      { 
+        multi-part-numbers    = repeat,
+        product-units         = power,                 
+      },
+  repeatunits /
+    true        .meta:n       =
+      { 
+        multi-part-numbers    = repeat,
+        product-units         = repeat,                 
+      },
+  repeatunits    .default:n = { true                                  },
+  retainplus     .meta:n    = { retain-explicit-plus    = #1          },
+  retainplus     .default:n = { true                                  },
+  seperr         .meta:n    = { separate-uncertainty    = #1          },
+  seperr         .default:n = { true                                  },
+  sepfour        .meta:n    = { group-four-digits       = true        },
+  sepfour        .default:n = { true                                  },
+  sf             .meta:n    = 
+    { 
+      round-mode      = figures,
+      round-precision = #1,
+    },
+  sign           .meta:n    = { explicit-sign           = #1          },
+  slash          .choice: ,
+  slash / 
+    slash        .meta:n    = { per-symbol              = /           },
+  slash / 
+    unknown      .meta:n    = { per symbol              = #1          },
+  stickyper      .meta:n    = { sticky-per              = #1          },
+  stickyper      .default:n = { true                                  },
+  strictarc      .code:n    = ,
+  tabalign       .meta:n    = 
+    {
+      table-number-alignment  = #1,
+      table-text-alignment    = #1,
+      table-unit-alignment    = #1
+    },
+  tabalignexp    .code:n    = ,
+  tabautofit     .meta:n    = { table-auto-round        = #1          },
+  tabformat      .meta:n    = { table-format            = #1          },
+  tabnumalign    .meta:n    = { table-number-alignment  = #1          },
+  tabparseonly   .meta:n    = { table-parse-only        = #1          },
+  tabparseonly   .default:n = { true                                  },
+  tabtextalign   .meta:n    = { table-text-numbers      = #1          },
+  tabunitalign   .meta:n    = { table-unit-alignment    = #1          },
+  textOmega      .meta:n    = { text-ohm                = #1          },
+  textcelsius    .meta:n    = { text-celsius            = #1          },
+  textdegree     .meta:n    = { text-degree             = #1          },
+  textminute     .meta:n    = { text-arcminute          = #1          },
+  textmode       .choice: ,
+  textmode / 
+    true         .meta:n    = { mode                    = text        },
+  textmode / 
+    false        .meta:n    = { mode                    = math        },
+  textmode       .default:n = { true                                  },
+  textmu         .meta:n    = { text-micro              = #1          },
+  textringA      .meta:n    = { text-angstrom           = #1          },
+  textrm         .meta:x    = 
+    { text-rm                 = \exp_not:c {#1}                       },
+  textsecond     .meta:n    = { text-arcsecond          = #1          },
+  textsf         .meta:x    = 
+    { text-sf                 = \exp_not:c {#1}                       },
+  texttt         .meta:x    = 
+    { text-tt                 = \exp_not:c {#1}                       },
+  tightpm        .meta:n    = { tight-spacing           = #1          },
+  tightpm        .default:n = { true                                  },
+  tophrase       .meta:n    = { range-phrase            = #1          },
+  trapambigerr   .choice: ,
+  trapambigerr   
+    / false      .meta:n    = { multi-part-units        = single      },
+  trapambigerr   
+    / true       .meta:n    = { multi-part-units        = brackets    },
+  trapambigerr   .default:n = { true                                  },
+  trapambigfrac  .meta:n    = { bracket-numbers         = #1          },
+  trapambigfrac  .default:n = { true                                  },
+  trapambigrange .choice: ,
+  trapambigrange  
+    / false      .meta:n    = { range-units             = single      },
+  trapambigrange   
+    / true       .meta:n    = { range-units             = brackets    },
+  trapambigrange .default:n = { true                                  },
+  unitcolor      .meta:n    = { unit-color              = #1          },
+  unitcolour     .meta:n    = { unit-color              = #1          },
+  unitmathrm     .meta:x    = 
+    { unit-math-rm            = \exp_not:c {#1}                       },
+  unitmathsf     .meta:x    = 
+    { unit-math-sf            = \exp_not:c {#1}                       },
+  unitmathsrm    .meta:x    = 
+    { unit-math-rm            = \exp_not:c {#1}                       },
+  unitmathssf    .meta:x    = 
+    { unit-math-sf            = \exp_not:c {#1}                       },
+  unitmathstt    .meta:x    = 
+    { unit-math-tt            = \exp_not:c {#1}                       },
+  unitmathtt     .meta:x    = 
+    { unit-math-tt            = \exp_not:c {#1}                       },
+  unitmode       .meta:n    = { unit-mode               = #1          },
+  unitsep        .choice: ,
+  unitsep / 
+    cdot         .meta:n    = 
+      { inter-unit-separator    = { } \cdot { }                       },
+  unitsep / 
+    comma        .meta:n    = { inter-unit-separator    = { {,} }     },
+  unitsep / 
+    fullstop     .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep / 
+    med          .meta:n    = { inter-unit-separator    = \:          },
+  unitsep / 
+    medium       .meta:n    = { inter-unit-separator    = \:          },
+  unitsep / 
+    none         .meta:n    = { inter-unit-separator    =             },
+  unitsep / 
+    period       .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep / 
+    space        .meta:n    = { inter-unit-separator    = \text { ~ } },
+  unitsep / 
+    stop         .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep / 
+    thick        .meta:n    = { inter-unit-separator    = \;          },
+  unitsep / 
+    thin         .meta:n    = { inter-unit-separator    = \,          },
+  unitsep / 
+    tightcdot    .meta:n    =
+      { inter-unit-separator    = \bgroup \cdot \egroup               },
+  unitsep / 
+    tighttimes   .meta:n    =
+      { inter-unit-separator    = \bgroup \times \egroup              },
+  unitsep / 
+    times        .meta:n   = { inter-unit-separator     = \times      },
+  unitsep / 
+    unknown      .meta:n   = { inter-unit-separator     = #1          },
+  unitspace      .choice: ,
+  unitspace / 
+    med          .meta:n   = { inter-unit-separator     = \:          },
+  unitspace / 
+    medium       .meta:n   = { inter-unit-separator     = \:          },
+  unitspace / 
+    none         .meta:n   = { inter-unit-separator     =             },
+  unitspace / 
+    space        .meta:n   = { inter-unit-separator     = \text { ~ } },
+  unitspace / 
+    thick        .meta:n   = { inter-unit-separator     = \;          },
+  unitspace / 
+    thin         .meta:n   = { inter-unit-separator     = \,          },
+  unitspace / 
+    unknown      .meta:n   = { inter-unit-separator     = #1          },
+  valuecolor     .meta:n   = { number-color             = #1          },
+  valuecolour    .meta:n   = { number-color             = #1          },
+  valuemathrm    .meta:x   = 
+    { number-math-rm           = \exp_not:c {#1}                      },
+  valuemathsf    .meta:x   = 
+    { number-math-sf           = \exp_not:c {#1}                      },
+  valuemathsrm   .meta:x   = 
+    { number-math-rm           = \exp_not:c {#1}                      },
+  valuemathssf   .meta:x   = 
+    { number-math-sf           = \exp_not:c {#1}                      },
+  valuemathstt   .meta:x   = 
+    { number-math-tt           = \exp_not:c {#1}                      },
+  valuemathtt    .meta:x   = 
+    { number-math-tt           = \exp_not:c {#1}                      },
+  valuemode      .meta:n   = { number-mode              = #1          },
+  valuesep        .choice: ,
+  valuesep / 
+    cdot         .meta:n    = 
+      { unit-value-separator    = { } \cdot { }                       },
+  valuesep / 
+    comma        .meta:n    = { unit-value-separator    = { {,} }     },
+  valuesep / 
+    fullstop     .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep / 
+    med          .meta:n    = { unit-value-separator    = \:          },
+  valuesep / 
+    medium       .meta:n    = { unit-value-separator    = \:          },
+  valuesep / 
+    none         .meta:n    = { unit-value-separator    =             },
+  valuesep / 
+    period       .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep / 
+    space        .meta:n    = { unit-value-separator    = \text { ~ } },
+  valuesep / 
+    stop         .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep / 
+    thick        .meta:n    = { unit-value-separator    = \;          },
+  valuesep / 
+    thin         .meta:n    = { unit-value-separator    = \,          },
+  valuesep / 
+    tightcdot    .meta:n    = 
+      { unit-value-separator    = \bgroup \cdot \egroup               },
+  valuesep / 
+    tighttimes   .meta:n    =
+      { unit-value-separator    = \bgroup \times \egroup              },
+  valuesep / 
+    times        .meta:n    = { unit-value-separator     = \times     },
+  valuesep / 
+    unknown      .meta:n    = { unit-value-separator     = #1         },
+  xspace         .meta:n    = { use-xspace               = #1         },
+  xpace          .default:n = { true                                  }
+} 
+%    \end{macrocode}
+%    
+%\begin{macro}{\newunit}
+%\begin{macro}{\renewunit}
+%\begin{macro}{\provideunit}
+% The functions for creating units from version one are easy to create.
+%    \begin{macrocode}
+\cs_set_eq:NN \newunit     \DeclareSIUnit
+\cs_set_eq:NN \renewunit   \DeclareSIUnit
+\cs_set_eq:NN \provideunit \DeclareSIUnit
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\end{macro}   
+%
+%\begin{macro}{\newpower}
+%\begin{macro}{\renewpower}
+%\begin{macro}{\providepower}
+% Slightly more complex: an optional argument to check. A simple 
+% assumption is made that it will be \texttt{post}: anything else
+% would not make sense anyway.
+%    \begin{macrocode}
+\NewDocumentCommand \newpower     { o m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+\NewDocumentCommand \renewpower   { o m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+\NewDocumentCommand \providepower { o m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\end{macro} 
+%
+%\begin{macro}{\newprefix}
+%\begin{macro}{\renewprefix}
+%\begin{macro}{\provideprefix}
+% Slightly more complex: an optional argument to check. A simple 
+% assumption is made that it will be \texttt{post}: anything else
+% would not make sense anyway.
+%    \begin{macrocode}
+\NewDocumentCommand \newprefix     { o m m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+\NewDocumentCommand \renewprefix   { o m m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+\NewDocumentCommand \provideprefix { o m m m } {
+  \IfNoValueTF {#1} 
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\end{macro}  
+%
+%\begin{macro}{\newqualifier}
+%\begin{macro}{\renewqualifier}
+%\begin{macro}{\providequalifier}
+% The functions for creating qualifiers are easy to create again.
+%    \begin{macrocode}
+\cs_set_eq:NN \newqualifier     \DeclareSIQualifier
+\cs_set_eq:NN \renewqualifier   \DeclareSIQualifier
+\cs_set_eq:NN \providequalifier \DeclareSIQualifier
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%\end{macro} 
+%
+%\begin{macro}{\Square}
+%\begin{macro}{\ssquare}
+% In version 1, \cs{square} is not used with these two alternatives
+% preferred.
+%    \begin{macrocode}
+\DeclareSIPrePower \Square  { 2 }
+\DeclareSIPrePower \ssquare { 2 }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\dersiemens}
-%\begin{macro}{\derweber}
-%\begin{macro}{\dertesla}
-%\begin{macro}{\derhenry}
-%\begin{macro}{\dercelsius}
-%\begin{macro}{\derlumen}
-%\begin{macro}{\derlux}
-%\begin{macro}{\derbecquerel}
-%\begin{macro}{\dergray}
-%\begin{macro}{\dersievert}
-%\begin{macro}{\derkatal}
-% In two blocks!
+%
+%\begin{macro}{\BAR}
+%\begin{macro}{\bbar}
+%\begin{macro}{\Day}
+%\begin{macro}{\dday}
+%\begin{macro}{\Gray}
+%\begin{macro}{\ggray}
+% Units which are given awkward names in version one.
 %    \begin{macrocode}
-  \newunit{\dersiemens}{\ampere\reciprocal\volt}
-  \newunit{\derweber}
-    {\squaremetre\kilogram\second\rpsquared\reciprocal\ampere}
-  \newunit{\dertesla}{\weber\rpsquare\metre}
-  \newunit{\derhenry}{\weber\reciprocal\ampere}
-  \newunit{\dercelsius}{\kelvin}
-  \newunit{\derlumen}{\candela\steradian}
-  \newunit{\derlux}{\lumen\rpsquare\metre}
-  \newunit{\derbecquerel}{\derhertz}
-  \newunit{\dergray}{\joule\reciprocal\kilogram}
-  \newunit{\dersievert}{\dergray}
-  \newunit{\derkatal}{\rp\second\usk\mole}
-\fi
+\DeclareSIUnit \BAR   { \bar }
+\DeclareSIUnit \bbar  { \bar }
+\DeclareSIUnit \Day   { \day }
+\DeclareSIUnit \dday  { \day }
+\DeclareSIUnit \Gray  { \gray }
+\DeclareSIUnit \ggray { \gray }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -13177,41 +13355,70 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\atomicmass}
+% Slightly different: given more complete names in version two.
+%    \begin{macrocode}
+\DeclareSIUnit \atomicmass { \atomicmassunit }
+\DeclareSIUnit \arcmin     { \arcminute }
+\DeclareSIUnit \arcsec     { \arcsecond }
+%    \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\are}
+%\begin{macro}{\curie}
+%\begin{macro}{\gal}
+%\begin{macro}{\millibar}
+%\begin{macro}{\rad}
+%\begin{macro}{\rem}
+%\begin{macro}{\roentgen}
+% Units which were defined in version one but are no longer listed
+% by the \textsc{bipm} as acceptable.
+%    \begin{macrocode}
+\DeclareSIUnit \are      { a }
+\DeclareSIUnit \curie    { Ci }
+\DeclareSIUnit \gal      { Gal }
+\DeclareSIUnit \millibar { \milli \bar }
+\DeclareSIUnit \rad      { rad }
+\DeclareSIUnit \rem      { rem }
+\DeclareSIUnit \roentgen { R }
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\radianbase}
-%\begin{macro}{\steradianbase}
-%\begin{macro}{\hertzbase}
-%\begin{macro}{\newtonbase}
-%\begin{macro}{\pascalbase}
-%\begin{macro}{\joulebase}
-%\begin{macro}{\wattbase}
-%\begin{macro}{\coulombbase}
-%\begin{macro}{\voltbase}
-%\begin{macro}{\faradbase}
-%\begin{macro}{\ohmbase}
-% Also the ``derived-in-base''.
+%
+%\begin{macro}{\micA}
+%\begin{macro}{\micmol}
+%\begin{macro}{\micl}
+%\begin{macro}{\micL}
+%\begin{macro}{\nanog}
+%\begin{macro}{\micg}
+%\begin{macro}{\picm}
+%\begin{macro}{\micm}
+%\begin{macro}{\Sec}
+%\begin{macro}{\mics}
+%\begin{macro}{\cmc}
+%\begin{macro}{\dmc}
+%\begin{macro}{\cms}
+% A few abbreviations which have been renamed.
 %    \begin{macrocode}
-\ifsi@old@derivedinbase
-  \newunit{\radianbase}{\metre\reciprocal\metre}
-  \newunit{\steradianbase}{\squaremetre\rpsquare\metre}
-  \newunit{\hertzbase}{\reciprocal\second}
-  \newunit{\newtonbase}{\metre\kilogram\second\rpsquared}
-  \newunit{\pascalbase}{\reciprocal\metre\kilogram\second%
-    \rpsquared}
-  \newunit{\joulebase}{\squaremetre\kilogram\second\rpsquared}
-  \newunit{\wattbase}{\squaremetre\kilogram\rpcubic\second}
-  \newunit{\coulombbase}{\ampere\second}
-  \newunit{\voltbase}
-    {\squaremetre\kilogram\rpcubic\second\reciprocal\ampere}
-  \newunit{\faradbase}
-    {\rpsquare\metre\reciprocal\kilogram\fourth\second\ampere%
-      \squared}
-  \newunit{\ohmbase}
-    {\squaremetre\kilogram\rpcubic\second\rpsquare\ampere}
+\DeclareSIUnit \micA   { \micro \ampere }
+\DeclareSIUnit \micmol { \micro \mole   }
+\DeclareSIUnit \micl   { \micro \litre  }
+\DeclareSIUnit \micL   { \micro \liter  }
+\DeclareSIUnit \nanog  { \nano  \gram   }
+\DeclareSIUnit \micg   { \micro \gram   }
+\DeclareSIUnit \picm   { \pico  \metre  }
+\DeclareSIUnit \micm   { \micro \metre  }
+\DeclareSIUnit \Sec    { \second }
+\DeclareSIUnit \mics   { \micro \second }
+\DeclareSIUnit \cmc    { \centi \metre \cubed }
+\DeclareSIUnit \dmc    { \deci  \metre \cubed }
+\DeclareSIUnit \cms    { \centi \metre \squared }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -13224,107 +13431,127 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\siemensbase}
-%\begin{macro}{\weberbase}
-%\begin{macro}{\teslabase}
-%\begin{macro}{\henrybase}
-%\begin{macro}{\celsiusbase}
-%\begin{macro}{\lumenbase}
-%\begin{macro}{\luxbase}
-%\begin{macro}{\becquerelbase}
-%\begin{macro}{\graybase}
-%\begin{macro}{\sievertbase}
-%\begin{macro}{\katalbase}
-% Also in two blocks.
-%    \begin{macrocode}
-  \newunit{\siemensbase}
-    {\rpsquare\metre\reciprocal\kilogram\cubic\second\ampere%
-       \squared}
-  \newunit{\weberbase}
-    {\squaremetre\kilogram\second\rpsquared\reciprocal\ampere}
-  \newunit{\teslabase}{\kilogram\second\rpsquared\reciprocal%
-     \ampere}
-  \newunit{\henrybase}
-    {\squaremetre\kilogram\second\rpsquared\rpsquare\ampere}
-  \newunit{\celsiusbase}{\kelvin}
-  \newunit{\lumenbase}{\candela\squaremetre\rpsquare\metre}
-  \newunit{\luxbase}{\candela\squaremetre\rpfourth\metre}
-  \newunit{\becquerelbase}{\hertzbase}
-  \newunit{\graybase}{\squaremetre\second\rpsquared}
-  \newunit{\sievertbase}{\graybase}
-  \newunit{\katalbase}{\rp\second\mole}
-\fi
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\parsec}
+%\begin{macro}{\lightyear}
+% A few units for astronomy that version 1 provided.
+%    \begin{macrocode}
+\DeclareSIUnit \parsec    { pc }
+\DeclareSIUnit \lightyear { ly }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
+%    
+%\begin{macro}{\gmol}
+%\begin{macro}{\kgmol}
+%\begin{macro}{\lbmol}
+% Slightly odd chemical engineering units, again provided in version 1.
+%    \begin{macrocode}
+\DeclareSIUnit \gmol  { g  \text { - } mol }
+\DeclareSIUnit \kgmol { kg \text { - } mol }
+\DeclareSIUnit \lbmol { lb \text { - } mol }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%
+%\begin{macro}{\molar}
+%\begin{macro}{\Molar}
+%\begin{macro}{\torr}
+% A few common units for chemistry from version 1. \cs{molar} is 
+% simply a handy abbreviation: \cs{Molar} is common but rather 
+% questionable.
+%    \begin{macrocode}
+\DeclareSIUnit \molar { \mole \per \cubic \deci \metre }
+\DeclareSIUnit \Molar { \textsc { m } }
+\DeclareSIUnit \torr  { Torr }
+%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%    
+%\begin{macro}{\gon}
+% A single unit for geophysics that version 1 included.
+%    \begin{macrocode}
+\DeclareSIUnit \gon    { gon }
+%    \end{macrocode}
 %\end{macro}
-% Any configuration file is used if found.
+%
 %    \begin{macrocode}
-\InputIfFileExists{SIunits.cfg}
-  {\si@log@inf{SIunits config file loaded}}
-  {\si@log@inf{SIunits config file not found}}
+%</version-1>
 %    \end{macrocode}
-%\iffalse
-%</SIunits>
-%<*hepunits>
-%\fi
-%\subsection{\pkg{hepunits}}
-% The \pkg{hepunits} package provides some rather odd unit names,
-% which are not really to be encouraged.
+%
+%\subsection{Abbreviated units}
+%
 %    \begin{macrocode}
-\ProvidesFile{si-hepunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     hepunits]
-\si@emulating{hepunits}{2007/09/27}
-\requiresiconfigs{SIunits,accepted,prefix,hep}
+%<*abbreviations>
 %    \end{macrocode}
-%\begin{macro}{\invbarn}
-%\begin{macro}{\invnanobarn}
-%\begin{macro}{\invpicobarn}
-%\begin{macro}{\invfemtobarn}
-%\begin{macro}{\invattobarn}
-%\begin{macro}{\invzeptobarn}
-%\begin{macro}{\invyoctobarn}
-% Inverses barn units.
+%    
 %    \begin{macrocode}
-\ifsi@old@noprefixcmds\else
-  \newunit{\invbarn}{\per\barn}
-  \newunit{\invnanobarn}{\per\nano\barn}
-  \newunit{\invpicobarn}{\per\pico\barn}
-  \newunit{\invfemtobarn}{\per\femto\barn}
-  \newunit{\invattobarn}{\per\atto\barn}
-  \newunit{\invzeptobarn}{\per\zepto\barn}
-  \newunit{\invyoctobarn}{\per\yocto\barn}
+\ProvidesExplFile {siunitx-abbreviations.cfg} {2010/05/23} {2.0}  
+  {siunitx: Abbreviated units}
+%    \end{macrocode}
+%
+% The abbreviation file contains a number of short (mainly two or
+% three letter) versions of the usual long names. They are divided up
+% into related groups, mainly to avoid an overly long list in one
+% place.
+%
+%\begin{macro}{\pA}
+%\begin{macro}{\nA}
+%\begin{macro}{\uA}
+%\begin{macro}{\mA}
+%\begin{macro}{\kA}
+% Currents.
+%    \begin{macrocode}
+\DeclareSIUnit \pA { \pico  \ampere }
+\DeclareSIUnit \nA { \nano  \ampere }
+\DeclareSIUnit \uA { \micro \ampere }
+\DeclareSIUnit \mA { \milli \ampere }
+\DeclareSIUnit \kA { \kilo  \ampere }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%\begin{macro}{\Hz}
+%\begin{macro}{\mHz}
+%\begin{macro}{\kHz}
+%\begin{macro}{\MHz}
+%\begin{macro}{\GHz}
+%\begin{macro}{\THz}
+% Then frequencies.
+%    \begin{macrocode}
+\DeclareSIUnit \Hz  {        \hertz }
+\DeclareSIUnit \mHz { \milli \hertz }
+\DeclareSIUnit \kHz { \kilo  \hertz }
+\DeclareSIUnit \MHz { \mega  \hertz }
+\DeclareSIUnit \GHz { \giga  \hertz }
+\DeclareSIUnit \THz { \tera  \hertz }
+%    \end{macrocode}
+%\end{macro}
+%\end{macro}
 %\end{macro}
-%\begin{macro}{\invnb}
-%\begin{macro}{\invpb}
-%\begin{macro}{\invfb}
-%\begin{macro}{\invab}
-%\begin{macro}{\invzb}
-%\begin{macro}{\invyb}
-% Also available abbreviated.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\begin{macro}{\fmol}
+%\begin{macro}{\pmol}
+%\begin{macro}{\nmol}
+%\begin{macro}{\umol}
+%\begin{macro}{\mmol}
+%\begin{macro}{\kmol}
+% Amounts of substance (moles).
 %    \begin{macrocode}
-  \newunit{\invnb}{\per\nano\barn}
-  \newunit{\invpb}{\per\pico\barn}
-  \newunit{\invfb}{\per\femto\barn}
-  \newunit{\invab}{\per\atto\barn}
-  \newunit{\invzb}{\per\zepto\barn}
-  \newunit{\invyb}{\per\yocto\barn}
-\fi
+\DeclareSIUnit \fmol { \femto \mole }
+\DeclareSIUnit \pmol { \pico  \mole }
+\DeclareSIUnit \nmol { \nano  \mole }
+\DeclareSIUnit \umol { \micro \mole }
+\DeclareSIUnit \mmol { \milli \mole }
+\DeclareSIUnit \kmol { \kilo  \mole }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -13332,34 +13559,48 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
+%\begin{macro}{\mV}
+%\begin{macro}{\kV}
+% Potentials.
+%    \begin{macrocode}
+\DeclareSIUnit \mV { \milli \volt }
+\DeclareSIUnit \kV { \kilo  \volt }
+%    \end{macrocode}
+%\end{macro}
 %\end{macro}
-%\begin{macro}{\invcmsqpersecond}
-%\begin{macro}{\invcmsqpersec}
-%\begin{macro}{\lumiunits}
-% Luminosity.
+%\begin{macro}{\ml}
+%\begin{macro}{\ul}
+%\begin{macro}{\mL}
+%\begin{macro}{\uL}
+% Volumes.
 %    \begin{macrocode}
-\newunit{\invcmsqpersecond}{\per\Square\centi\metre\per\second}
-\newunit{\invcmsqpersec}{\per\Square\centi\metre\per\second}
-\newunit{\lumiunits}{\per\Square\centi\metre\per\second}
+\DeclareSIUnit \ml { \milli \litre }
+\DeclareSIUnit \ul { \micro \litre }
+\DeclareSIUnit \mL { \milli \liter }
+\DeclareSIUnit \uL { \micro \liter }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\inveV}
-%\begin{macro}{\minveV}
-%\begin{macro}{\minveV}
-%\begin{macro}{\kinveV}
-%\begin{macro}{\MinveV}
-%\begin{macro}{\GinveV}
-%\begin{macro}{\TinveV}
-% The inverse of an electron-volt, plus prefixes.
+%\end{macro}
+%\begin{macro}{\fg}
+%\begin{macro}{\pg}
+%\begin{macro}{\ng}
+%\begin{macro}{\ug}
+%\begin{macro}{\mg}
+%\begin{macro}{\g}
+%\begin{macro}{\kg}
+%\begin{macro}{\amu}
+% Masses.
 %    \begin{macrocode}
-\newunit{\inveV}{\per\electronvolt}
-\newunit{\minveV}{\per\milli\electronvolt}
-\newunit{\kinveV}{\per\kilo\electronvolt}
-\newunit{\MinveV}{\per\mega\electronvolt}
-\newunit{\GinveV}{\per\giga\electronvolt}
-\newunit{\TinveV}{\per\tera\electronvolt}
+\DeclareSIUnit \fg  { \femto \gram }
+\DeclareSIUnit \pg  { \pico  \gram }
+\DeclareSIUnit \ng  { \nano  \gram }
+\DeclareSIUnit \ug  { \micro \gram }
+\DeclareSIUnit \mg  { \milli \gram }
+\DeclareSIUnit \g   { \gram }
+\DeclareSIUnit \kg  { \kilo \gram }
+\DeclareSIUnit \amu { \atomicmassunit }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
@@ -13368,493 +13609,181 @@ author.
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\eVoverc}
-%\begin{macro}{\eVovercsq}
-% Some combinations of electron-volts and the speed of light.  As
-% these are called |over|, they are set with a slash.  The
-% \opt{eVcorrb} values have been set for Computer Modern.
+%\end{macro}
+%\begin{macro}{\kJ}
+%\begin{macro}{\eV}
+%\begin{macro}{\meV}
+%\begin{macro}{\keV}
+%\begin{macro}{\MeV}
+%\begin{macro}{\GeV}
+%\begin{macro}{\TeV}
+%\begin{macro}{\kWh}
+% Energies.
 %    \begin{macrocode}
-\newunit[per=slash,eVcorrb=0.6ex]{\eVoverc}
-  {\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\eVovercsq}
-  {\electronvolt\per\Square\clight}
+\DeclareSIUnit \kJ  { \kilo \joule }
+\DeclareSIUnit \eV  { \electronvolt }
+\DeclareSIUnit \meV { \milli \electronvolt }
+\DeclareSIUnit \keV { \kilo  \electronvolt }
+\DeclareSIUnit \MeV { \mega  \electronvolt }
+\DeclareSIUnit \GeV { \giga  \electronvolt }
+\DeclareSIUnit \TeV { \tera  \electronvolt }
+\DeclareSIUnitWithOptions \kWh { \kilo \watt \hour }
+  { inter-unit-separator = }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\meVoverc}
-%\begin{macro}{\keVoverc}
-%\begin{macro}{\MeVoverc}
-%\begin{macro}{\GeVoverc}
-%\begin{macro}{\TeVoverc}
-% Prefixed combinations, first of the speed of light.
-%    \begin{macrocode}
-\newunit[per=slash,eVcorrb=0.6ex]{\meVoverc}
-  {\milli\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\keVoverc}
-  {\kilo\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\MeVoverc}
-  {\mega\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\GeVoverc}
-  {\giga\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\TeVoverc}
-  {\tera\electronvolt\per\clight}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\meVovercsq}
-%\begin{macro}{\keVovercsq}
-%\begin{macro}{\MeVovercsq}
-%\begin{macro}{\GeVovercsq}
-%\begin{macro}{\TeVovercsq}
-% Then of the square.
+%\end{macro}
+%\begin{macro}{\pm}
+%\begin{macro}{\nm}
+%\begin{macro}{\um}
+%\begin{macro}{\mm}
+%\begin{macro}{\cm}
+%\begin{macro}{\dm}
+%\begin{macro}{\km}
+% Lengths.
 %    \begin{macrocode}
-\newunit[per=slash,eVcorrb=0.6ex]{\meVovercsq}
-  {\milli\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\keVovercsq}
-  {\kilo\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\MeVovercsq}
-  {\mega\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\GeVovercsq}
-  {\giga\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\TeVovercsq}
-  {\tera\electronvolt\per\Square\clight}
+\DeclareSIUnit \nm { \nano  \metre }
+\DeclareSIUnit \pm { \pico  \metre }
+\DeclareSIUnit \um { \micro \metre }
+\DeclareSIUnit \mm { \milli \metre }
+\DeclareSIUnit \cm { \centi \metre }
+\DeclareSIUnit \dm { \deci  \metre }
+\DeclareSIUnit \km { \kilo  \metre }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\iffalse
-%</hepunits>
-%<*fancynum>
-%\fi
-%\subsection{\pkg{fancynum}}
-% \pkg{fancynum} only does things with numbers, so there is only
-% a little emulation and a few macros needed.
-%    \begin{macrocode}
-\ProvidesFile{si-fancynum.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     fancynum]
-\si@emulating{fancynum}{2000/08/08 0.92}
-\sisetup{decimalsymbol=cdot,digitsep=comma}
-%    \end{macrocode}
-%\begin{macro}{\fnum}
-% The \cs{fnum} macro is rather restricted, but this is not
-% reproduced.  Instead, it is \cs{let} as an alias to the \cs{num}
-% macro.
-%    \begin{macrocode}
-\let\fnum\num
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\setfnumdsym}
-%\begin{macro}{\setfnumgsym}
-%\begin{macro}{\setfnummsym}
-% The control macros are defined.
+%\end{macro}
+%\begin{macro}{\s}
+%\begin{macro}{\as}
+%\begin{macro}{\fs}
+%\begin{macro}{\ps}
+%\begin{macro}{\ns}
+%\begin{macro}{\us}
+%\begin{macro}{\ms}
+% Finally, times.
 %    \begin{macrocode}
-\newcommand*{\setfnumdsym}[1]{\sisetup{decimalsymbol={#1}}}
-\newcommand*{\setfnumgsym}[1]{\sisetup{digitsep={#1}}}
-\newcommand*{\setfnummsym}[1]{\sisetup{expproduct={#1}}}
+\DeclareSIUnit \s  { \second }
+\DeclareSIUnit \as { \atto  \second }
+\DeclareSIUnit \fs { \femto \second }
+\DeclareSIUnit \ps { \pico  \second }
+\DeclareSIUnit \ns { \nano  \second }
+\DeclareSIUnit \us { \micro \second }
+\DeclareSIUnit \ms { \milli \second }
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-% The various package options are now processed if necessary.
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%\end{macro}
+%
 %    \begin{macrocode}
-\ifsi@old@english
-  \sisetup{decimalsymbol=cdot,digitsep=comma}
-\fi
-\ifsi@old@french
-  \sisetup{decimalsymbol=comma,digitsep=fullstop}
-\fi
-\ifsi@old@tight
-  \sisetup{expproduct=tighttimes}
-\fi
-\ifsi@old@loose
-  \sisetup{expproduct=times}
-\fi
-\ifsi@old@thinspaces
-  \sisetup{digitsep=thin}
-\fi
-\ifsi@old@commas
-  \sisetup{digitsep=comma}
-\fi
-\ifsi@old@plain
-  \sisetup{digitsep=none}
-\fi
-%    \end{macrocode}
+%</abbreviations>
+%    \end{macrocode}   
+%    
+%\subsection{Binary units}
 %
-%\iffalse
-%</fancynum>
-%<*fancyunits>
-%\fi
-%\subsection{\pkg{fancyunits}}
-% The \pkg{fancyunits} package is not available on \textsc{ctan}, but
-% is available from its authors homepage \cite{fancyunits}.  It is
-% similar to \SIunits, and so most of the code is shared here.
-% However, a few bits of set up occur first, and an emulation-clash
-% test is needed.
-%    \begin{macrocode}
-\ProvidesFile{si-fancyunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     fancyunits]
-\si@emulating{fancyunits}{2007/02/01 v1.0.1}
-\si@ifloaded{SIunits}
-  {\si@log@err{SIunits emulation loaded\MessageBreak before
-    fancyunits emulation}{You need to load the fancyunits
-    emualtion\MessageBreak code before that for
-    SIunits.\MessageBreak Try emulate=fancyunits as the first
-    option when\MessageBreak loading siunitx}}{}
-%    \end{macrocode}
-%\begin{macro}{\si@siu@newunithook}
-%\begin{macro}{\si@siu@newunitxhook}
-% To create the extra macros provided by \pkg{fancyunits}, the
-% \SIunits emulation code is changed to add the ``\texttt{uf}''
-% variants.
-%    \begin{macrocode}
-\newcommand*{\si@siu@newunithook}[3][]{%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3uf\endcsname}%
-  \renewcommand*{\si@tempb}{stickyper,per=fraction,
-    fraction=nice}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3Uf\endcsname}%
-  \renewcommand*{\si@tempb}{stickyper,per=fraction,
-    fraction=frac}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \noexpand\def\noexpand\si@frc@hook{\noexpand\textstyle}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3UF\endcsname}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \noexpand\def\noexpand\si@frc@hook{\noexpand\displaystyle}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}}
-\newcommand*{\si@siu@newunitxhook}[4]{%
-  \expandafter\newunit\expandafter{\csname #1per#2uf\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=nice}%
-     #3\si@per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2Uf\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=frac}%
-     \renewcommand*{\si@frc@hook}{\textstyle}%
-     #3\si@per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2UF\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=frac}%
-     \renewcommand*{\si@frc@hook}{\displaystyle}%
-     #3\si@per#4}}
-%    \end{macrocode}
-%\end{macro}
-%\end{macro}
-% With that done, the emulation modules can be loaded.
-%    \begin{macrocode}
-\requiresiconfigs{SIunits,addn,astro}
-\sisetup{obeyall}
-%    \end{macrocode}
-% There is one \pkg{fancyunits}-specific option to handle.  The other
-% options all get sent through to the \SIunits system.\footnote{As
-% \SIunits is rather more widely known than \pkg{fancyunits}, any
-% other options which could be for either are assumed to be for
-% \SIunits.}
-%    \begin{macrocode}
-\ifsi@old@spaceqspace
-  \sisetup{valuesep=space}
-\fi
+%    \begin{macrocode}
+%<*binary>
+%    \end{macrocode}  
+%    
+%    \begin{macrocode}
+\ProvidesExplFile {siunitx-binary.cfg} {2010/05/23} {2.0}
+  {siunitx: Binary units}
 %    \end{macrocode}
-%\begin{macro}{\paminute}
-%\begin{macro}{\parsecond}
-%\begin{macro}{\AstroE}
-%\begin{macro}{\oersted}
-%\begin{macro}{\ton}
-% \pkg{fancyunits} provides some extra units, plus tonne spelled
-% incorrectly (again).
+%    
+%\begin{macro}{\kibi}
+%\begin{macro}{\mebi}
+%\begin{macro}{\gibi}
+%\begin{macro}{\tebi}
+%\begin{macro}{\pebi}
+%\begin{macro}{\exbi}
+%\begin{macro}{\zebi}
+%\begin{macro}{\yobi}
+% The binary units as specified by the IEC.
 %    \begin{macrocode}
-\newunit{\paminute}{'}
-\newunit{\parsecond}{''}
-\newunit{\AstroE}{AE}
-\newunit{\oersted}{OE}
-\provideunit{\ton}{t}
+\DeclareBinaryPrefix \kibi { Ki } { 10 } 
+\DeclareBinaryPrefix \mebi { Mi } { 20 } 
+\DeclareBinaryPrefix \gibi { Gi } { 30 } 
+\DeclareBinaryPrefix \tebi { Ti } { 40 } 
+\DeclareBinaryPrefix \pebi { Pi } { 50 } 
+\DeclareBinaryPrefix \exbi { Ei } { 60 } 
+\DeclareBinaryPrefix \zebi { Zi } { 70 } 
+\DeclareBinaryPrefix \yobi { Yi } { 80 } 
 %    \end{macrocode}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
 %\end{macro}
-%\begin{macro}{\decaD}
-% An additional prefix.
-%    \begin{macrocode}
-\let\decaD\decad
-%    \end{macrocode}
 %\end{macro}
-%\begin{macro}{\ufrac}
-%\begin{macro}{\Ufrac}
-%\begin{macro}{\UFrac}
-% The fractional unit macros need to be reproduced.
-%    \begin{macrocode}
-\newcommand*{\ufrac}[2]{%
-  \si[stickyper,per=fraction,fraction=nice]{#1\si@per#2}}
-\newcommand*{\Ufrac}[2]{%
-  \ensuremath{\textstyle{%
-    \si[stickyper,per=fraction,fraction=frac]{#1\si@per#2}}}}
-\newcommand*{\UFrac}[2]{%
-  \ensuremath{\displaystyle{%
-    \si[stickyper,per=fraction,fraction=frac]{#1\si@per#2}}}}
-%    \end{macrocode}
 %\end{macro}
 %\end{macro}
-%\end{macro}
-%\begin{macro}{\pow}
-% A slightly-shorted named \cs{power}.
-%    \begin{macrocode}
-\let\pow\power
-%    \end{macrocode}
-%\end{macro}
-%\begin{macro}{\Squaremetre}
-% An alias for \cs{squaremetre}.
+%\begin{macro}{\bit}
+%\begin{macro}{\byte}
+% Now the units.
 %    \begin{macrocode}
-\let\Squaremetre\squaremetre
+\DeclareSIUnit \bit  { bit }
+\DeclareSIUnit \byte { B }
 %    \end{macrocode}
 %\end{macro}
-% As with \SIunits, there is now a list of compound units to add.
-% Only a few are not covered by the \SIunits emulation.
+%\end{macro} 
+%
 %    \begin{macrocode}
-\si@siu@newunit{Gray}{second}
-\si@siu@newunit[square]{Squaremetre}{metre}
-\si@siu@newunitx{Squaremetre}{newtonsecond}{\Square\metre}
-  {\newton\second}
-\si@siu@newunit{Squaremetre}{second}
-\si@siu@newunit[square]{Squaremetre}{squaresecond}
-\si@siu@newunit{Squaremetre}{kilogram}
-\si@siu@newunit[cubic]{Squaremetre}{second}
-%    \end{macrocode}
-%\iffalse
-%</fancyunits>
-%\fi
+%</binary>
+%    \end{macrocode}   
 %
-%\Finale
-%\iffalse
-%<*refs>
-@misc{BIPM:EN,
-  note = {\url{http://www.bipm.org/en/si/}},
-}
-
-@misc{BIPM:FR,
-  note = {\url{http://www.bipm.org/fr/si/}},
-}
-
-@misc{BIPM:PDF,
-  note = {\url{http://www.bipm.org/en/si/si_brochure/}},
-}
-
-@misc{Eijkhout,
-  author =       {Victor Eijkhout},
-  note =         {\url{http://www.eijkhout.net/tbt/}},
-  title =        {{\TeX} by {T}opic},
-  year =         {2007},
-}
-
-@misc{fancyunits,
-  author = {Heiko Bauke},
-  note = {\url{http://www.mpi-hd.mpg.de/personalhomes/bauke/LaTeX/Tips_und_Tricks/fancyunits/index.php}},
-  title = {\pkg{fancyunits}},
-  year = 2007,
-}
-
-@misc{IUPAC,
-  note = {\url{http://old.iupac.org/publications/books/gbook/green_book_2ed.pdf}},
-  title = {The \textsc{iupac} {G}reen {B}ook},
-  year = 1993,
-}
-
-@misc{NIST,
-  note = {\url{http://physics.nist.gov/cuu/Units/index.html}},
-}
-%</refs>
-%<*jawltxdoc>
-\NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{jawltxdoc}
-\usepackage[T1]{fontenc}
-\usepackage{lmodern}
-\usepackage[final]{listings,graphicx,microtype}
-\usepackage[scaled=0.95]{helvet}
-\usepackage[osf]{mathpazo}
-\usepackage{booktabs,array,url,courier,xspace,varioref}
-\usepackage{upgreek,ifpdf,float,caption,longtable,babel}
-\begingroup
-  \@ifundefined{eTeXversion}
-    {\aftergroup\@gobble}
-    {\aftergroup\@firstofone}
-\endgroup
-{\usepackage{etoolbox}}
-\floatstyle{plaintop}
-\restylefloat{table}
-\labelformat{figure}{\figurename~#1}
-\labelformat{table}{\tablename~#1}
-\IfFileExists{\jobname.sty}
-  {\usepackage{\jobname}}{}
-\usepackage[numbered]{hypdoc}
-\setcounter{IndexColumns}{2}
-\newlength\LaTeXwidth
-\newlength\LaTeXoutdent
-\newlength\LaTeXgap
-\setlength\LaTeXgap{1em}
-\setlength\LaTeXoutdent{-0.15\textwidth}
-\newbox\lst@samplebox
-\edef\LaTeXexamplefile{\jobname.tmp}
-\lst@RequireAspects{writefile}
-\lstnewenvironment{LaTeXexample}[1][example]{%
-  \global\let\lst@intname\@empty
-  \ifcsname LaTeXcode#1\endcsname
-    \expandafter\let\expandafter\LaTeXcode
-      \csname LaTeXcode#1\endcsname
-    \expandafter\let\expandafter\LaTeXcodeend
-      \csname LaTeXcode#1end\endcsname
-  \else
-    \PackageError{jawltxdoc}
-      {Undefined example type `#1'}
-      \@ehd
-    \let\LaTeXcode\relax
-    \let\LaTeXcodeend\relax
-  \fi
-  \LaTeXcode}
-  {\lst@EndWriteFile
-   \LaTeXcodeend}
-\newcommand*{\LaTeXcodeexample}{%
-  \setbox\lst@samplebox=\hbox\bgroup
-  \LaTeXcodefloat}
-\let\LaTeXcoderesultonly\LaTeXcodeexample
-\newcommand*{\LaTeXcodeexampleend}{%
-  \egroup
-  \setlength\LaTeXwidth{\wd\lst@samplebox}%
-  \begin{list}{}{%
-    \setlength\itemindent{0pt}
-    \setlength\leftmargin\LaTeXoutdent
-    \setlength\rightmargin{0pt}}%
-    \item
-      \setlength\LaTeXoutdent{-0.15\textwidth}
-      \begin{minipage}[c]{%
-        \textwidth-\LaTeXwidth-\LaTeXoutdent-\LaTeXgap}
-        \LaTeXcodefloatend
-      \end{minipage}%
-      \hfill
-      \begin{minipage}[c]{\LaTeXwidth}%
-        \hbox to\linewidth{\box\lst@samplebox\hss}%
-      \end{minipage}%
-  \end{list}}
-\newcommand*{\LaTeXcodefloat}{%
-  \setkeys{lst}{tabsize=4,gobble=3,breakindent=0pt,
-    basicstyle=\small\ttfamily,basewidth=0.51em,
-    keywordstyle=\color{blue}}%
-  \lst@BeginAlsoWriteFile{\LaTeXexamplefile}}
-\let\LaTeXcodenoexample\LaTeXcodefloat
-\let\LaTeXcodenoexampleend\@empty
-\newcommand*{\LaTeXcodefloatend}{%
-  \MakePercentComment\catcode`\^^M=10\relax
-  \small
-  {\setkeys{lst}{SelectCharTable=\lst@ReplaceInput{\^\^I}%
-    {\lst@ProcessTabulator}}%
-    \leavevmode \input{\LaTeXexamplefile}}%
-  \MakePercentIgnore}
-\newcommand*{\LaTeXcoderesultonlyend}{\egroup\LaTeXcodefloatend}
-\lstnewenvironment{BibTeXexample}{%
-  \global\let\lst@intname\@empty
-  \setbox\lst@samplebox=\hbox\bgroup
-  \setkeys{lst}{tabsize=4,gobble=3,breakindent=0pt,
-    basicstyle=\small\ttfamily,basewidth=0.51em,
-    keywordstyle=\color{black}}
-  \lst@BeginAlsoWriteFile{\LaTeXexamplefile}}
- {\lst@EndWriteFile
-   \LaTeXcodeexampleend}
-\newcommand*{\DescribeOption}{%
-  \leavevmode\@bsphack\begingroup\MakePrivateLetters
-  \Describe@Option}
-\newcommand*{\Describe@Option}[1]{\endgroup
-              \marginpar{\raggedleft\PrintDescribeEnv{#1}}%
-              \SpecialOptionIndex{#1}\@esphack\ignorespaces}
-\newcommand*{\SpecialOptionIndex}[1]{\@bsphack
-    \index{#1\actualchar{\protect\ttfamily#1}
-           (option)\encapchar usage}%
-    \index{options:\levelchar#1\actualchar{\protect\ttfamily#1}%
-      \encapchar usage}\@esphack}
-\newcommand*{\indexopt}[1]{\DescribeOption{#1}\opt{#1}}
-\newcommand*{\DescribeOptionInfo}[2]{%
-  \DescribeOption{#1}%
-  \opt{#1=\meta{#2}}\xspace}
-\newcommand*{\ofixarg}[1]{%
-  {\ttfamily[}%
-  \ifmmode \expandafter \nfss@text \fi
-  {%
-    \meta@font@select
-    \edef\meta@hyphen@restore{%
-      \hyphenchar\the\font\the\hyphenchar\font}%
-    \hyphenchar\font\m@ne
-    \language\l@nohyphenation
-    #1\/%
-    \meta@hyphen@restore
-    }%
-    {\ttfamily]}}
-\newcommand*{\pkg}[1]{\textsf{#1}}
-\newcommand*{\currpkg}{\pkg{\jobname}\xspace}
-\newcommand*{\opt}[1]{\texttt{#1}}
-\newcommand*{\defaultopt}[1]{\opt{\textbf{#1}}}
-\newcommand*{\file}[1]{\texttt{#1}}
-\newcommand*{\ext}[1]{\file{.#1}}
-\newcommand*{\latin}[1]{\emph{#1}}
-\newcommand*{\etc}{%
-  \@ifnextchar.
-    {\latin{etc}}
-    {\latin{etc}.\xspace}}
-\newcommand*{\eg}{%
-  \@ifnextchar.
-    {\latin{e.g}}
-    {\latin{e.g}.\xspace}}
-\newcommand*{\ie}{%
-  \@ifnextchar.
-    {\latin{i.e}}
-    {\latin{i.e}.\xspace}}
-\newcommand*{\etal}{%
-  \@ifnextchar.
-    {\latin{et~al.}}
-    {\latin{et~al}.\xspace}}
-\newcommand*{\AMS}{{\protect\usefont{OMS}{cmsy}{m}{n}%
-  A\kern-.1667em\lower.5ex\hbox{M}\kern-.125emS}}
-\providecommand*{\eTeX}{\ensuremath{\varepsilon}-\TeX}
-\DeclareRobustCommand*{\XeTeX}
-  {X\kern-.125em\lower.5ex\hbox{\reflectbox{E}}\kern-.1667em\TeX}
-\providecommand*{\CTAN}{\textsc{ctan}}
-\@ifpackageloaded{etoolbox}
-  {\patchcmd{\@addmarginpar}
-    {\@latex@warning@no@line {Marginpar on page \thepage\space moved}}
-    {\relax}{}{}}
-  {}
-\newcounter{argument}
-\g@addto@macro\endmacro{\setcounter{argument}{0}}
-\newcommand*\darg[1]{%
-  \stepcounter{argument}%
-  {\ttfamily\char`\#\theargument~:~}#1\par\noindent\ignorespaces}
-\newcommand*\doarg[1]{%
-  \stepcounter{argument}%
-  {\ttfamily\makebox[0pt][r]{[}%
-   \char`\#\theargument]:~}#1\par\noindent\ignorespaces}
-%</jawltxdoc>
-%\fi
+%\end{implementation}
+% 
+%\begin{thebibliography}{1}
+%  
+%  \bibitem{BIPM}
+%    \emph{The International System of Units (SI)},
+%    \url{http://www.bipm.org/en/si/}.
+%    
+%  \bibitem{NIST}
+%    \emph{International System of Units from NIST},
+%    \url{http://physics.nist.gov/cuu/Units/index.html}.
+%    
+%  \bibitem{SI:2.1}
+%    \emph{SI base units},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter2/2-1/}.
+%      
+%  \bibitem{SI:2.2.2}
+%    \emph{Units with special names and symbols; units that 
+%      incorporate special names and symbols},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html}.
+%      
+%  \bibitem{SI:3.1}
+%    \emph{SI Prefixes},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter3/prefixes.html}.
+%      
+%  \bibitem{SI:4.1.T6}
+%    \emph{Non-SI units accepted for use with the International 
+%      System of Units},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter4/table6.html}.
+%      
+%  \bibitem{SI:4.1.T7}
+%    \emph{Non-SI units whose values in SI units must be obtained 
+%      experimentally},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter4/table7.html}.
+%     
+%  \bibitem{SI:4.1.T8}
+%    \emph{Other non-SI units},
+%    \url{http://www.bipm.org/en/si/si_brochure/chapter4/table8.html}.
+%      
+%\end{thebibliography}
+%
+%\PrintChanges
+%
+%\PrintIndex
\ No newline at end of file
diff --git a/Master/texmf-dist/source/latex/siunitx/siunitx.ins b/Master/texmf-dist/source/latex/siunitx/siunitx.ins
index 7b9ed834e45..e6388ab7554 100644
--- a/Master/texmf-dist/source/latex/siunitx/siunitx.ins
+++ b/Master/texmf-dist/source/latex/siunitx/siunitx.ins
@@ -43,11 +43,8 @@ This work is "maintained" (as per LPPL maintenance status) by
 
 This work consists of the file  siunitx.dtx
           and the derived files siunitx.pdf,
-                                siunitx.sty
-                                siunitx.bib,
-                                siunitx.ins,
-                                siunitx-bug.tex and
-                                various .cfg files.
+                                siunitx.sty and
+                                siunitx.ins.
 
 \endpostamble
 \usedir{tex/latex/siunitx}
@@ -55,33 +52,11 @@ This work consists of the file  siunitx.dtx
   \file{\jobname.sty}{\from{\jobname.dtx}{package}}
 }
 \usedir{tex/latex/siunitx/config}
-\generate{\file{si-SIunits.cfg}{\from{\jobname.dtx}{SIunits}}
-          \file{si-sistyle.cfg}{\from{\jobname.dtx}{sistyle}}
-          \file{si-unitsdef.cfg}{\from{\jobname.dtx}{unitsdef}}
-          \file{si-units.cfg}{\from{\jobname.dtx}{units}}
-          \file{si-hepunits.cfg}{\from{\jobname.dtx}{hepunits}}
-          \file{si-fancynum.cfg}{\from{\jobname.dtx}{fancynum}}
-          \file{si-fancyunits.cfg}{\from{\jobname.dtx}{fancyunits}}
-}
-\generate{\file{si-prefix.cfg}{\from{\jobname.dtx}{prefix}}
-          \file{si-named.cfg}{\from{\jobname.dtx}{named}}
-          \file{si-prefixed.cfg}{\from{\jobname.dtx}{prefixed}}
-          \file{si-addn.cfg}{\from{\jobname.dtx}{addn}}
-          \file{si-accepted.cfg}{\from{\jobname.dtx}{accepted}}
-          \file{si-physical.cfg}{\from{\jobname.dtx}{physical}}
-          \file{si-abbr.cfg}{\from{\jobname.dtx}{abbr}}
-}
-\generate{\file{si-synchem.cfg}{\from{\jobname.dtx}{synchem}}
-          \file{si-hep.cfg}{\from{\jobname.dtx}{hep}}
-          \file{si-astro.cfg}{\from{\jobname.dtx}{astro}}
-          \file{si-geophys.cfg}{\from{\jobname.dtx}{geophys}}
-          \file{si-chemeng.cfg}{\from{\jobname.dtx}{chemeng}}
-          \file{si-binary.cfg}{\from{\jobname.dtx}{binary}}
-}
-\generate{\file{si-UK.cfg}{\from{\jobname.dtx}{UK}}
-          \file{si-USA.cfg}{\from{\jobname.dtx}{USA}}
-          \file{si-DE.cfg}{\from{\jobname.dtx}{DE}}
-          \file{si-ZA.cfg}{\from{\jobname.dtx}{ZA}}
+\generate{
+  \file{siunitx-abbreviations.cfg}
+    {\from{\jobname.dtx}{config,abbreviations}}
+  \file{siunitx-binary.cfg}{\from{\jobname.dtx}{config,binary}}
+  \file{siunitx-version-1.cfg}{\from{\jobname.dtx}{config,version-1}}
 }
 \endbatchfile
 %% 
@@ -100,11 +75,8 @@ This work consists of the file  siunitx.dtx
 %% 
 %% This work consists of the file  siunitx.dtx
 %%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
+%%                                 siunitx.sty and
+%%                                 siunitx.ins.
 %% 
 %%
 %% End of file `siunitx.ins'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-DE.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-DE.cfg
deleted file mode 100644
index 7c233a15ba3..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-DE.cfg
+++ /dev/null
@@ -1,49 +0,0 @@
-%%
-%% This is file `si-DE.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `DE')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-DE.cfg}
-  [2010/02/22 v1.4c siunitx: Germany locale]
-\sisetup{
-  unitsep=cdot,
-  valuesep=thin,
-  decimalsymbol=comma,
-  expproduct=cdot,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ bis }}}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-DE.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-SIunits.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-SIunits.cfg
deleted file mode 100644
index d8d97003060..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-SIunits.cfg
+++ /dev/null
@@ -1,346 +0,0 @@
-%%
-%% This is file `si-SIunits.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `SIunits')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-SIunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     SIunits]
-\si@emulating{SIunits}{2007/12/02 v1.36}
-\sisetup{
-  unitsep=thick,
-  valuesep=thick,
-  prefixproduct=\si@valuesep,
-  trapambigfrac=false,
-  stickyper}
-\requiresiconfigs{prefix,named,accepted,physical}
-\newcommand*{\reciprocal}{\sisetup{per=reciprocal}\si@per}
-\let\rp\reciprocal
-\renewcommand*{\per}{\sisetup{per=slash}\si@per}
-\newcommand*{\usk}{}
-\newcommand*{\power}[1]{#1\tothe}
-\newcommand*{\rpsquare}{\sisetup{per=reciprocal}\si@per\Square}
-\newcommand*{\rpcubic}{\sisetup{per=reciprocal}\si@per\cubic}
-\newpower{\fourth}{4}
-\newcommand*{\rpfourth}{\sisetup{per=reciprocal}\si@per\fourth}
-\newcommand*{\rpsquared}{%
-  \sisetup{per=reciprocal}\si@unt@pertrue\si@unt@perseentrue%
-    \squared}
-\newcommand*{\rpcubed}{%
-  \sisetup{per=reciprocal}\si@unt@pertrue\cubed}
-\newcommand*{\SIsetup}[1]{%
-  \@for\si@tempa:=#1\do{%
-    \@ifundefined{ifsi@old@#1}
-      {\si@log@warn{Unknown SIunits option `#1'}}
-      {\csname si@old@#1true\endcsname}}
-  \si@siu@setup}
-\newcommand*{\si@siu@setup}{%
-  \ifsi@old@cdot
-    \sisetup{unitsep=cdot}%
-  \fi
-  \ifsi@old@thickspace
-    \sisetup{unitsep=thick}%
-  \fi
-  \ifsi@old@mediumspace
-    \sisetup{unitsep=medium}%
-  \fi
-  \ifsi@old@thinspace
-    \sisetup{unitsep=thin}%
-  \fi
-  \ifsi@old@thickqspace
-    \sisetup{valuesep=thick}%
-  \fi
-  \ifsi@old@mediumqspace
-    \sisetup{valuesep=medium}%
-  \fi
-  \ifsi@old@thinqspace
-    \sisetup{valuesep=thin}%
-  \fi}
-\si@siu@setup
-\ifsi@old@squaren
-  \newpower{\squaren}{2}
-\fi
-\AtBeginDocument{%
-  \@ifundefined{square}
-    {\newpower{\square}{2}}
-    {\ifsi@old@amssymb
-       \renewpower{\square}{2}
-     \else
-       \ifsi@old@squaren\else
-         \si@log@warn{\string\square\space already
-           defined\MessageBreak SIunits mode may cause
-           errors}%
-       \fi
-     \fi}}
-\AtBeginDocument{
-  \@ifundefined{gray}
-    {\newunit{\gray}{Gy}}
-    {\ifsi@old@pstricks
-       \renewunit{\gray}{Gy}
-     \else
-       \ifsi@old@Gray\else
-         \si@log@warn{\string\gray\space already
-           defined\MessageBreak SIunits mode may cause
-           errors}%
-       \fi
-     \fi}}
-\ifsi@old@italian
-  \let\unita\SI
-\else
-  \let\unit\SI
-\fi
-\ifsi@old@textstyle
-  \sisetup{mode=text}
-\fi
-\ifsi@old@binary
-  \sisetup{alsoload=binary}
-\fi
-\newunit[valuesep=none]{\arcminute}{\si@sym@minute}
-\newunit[valuesep=none]{\arcsecond}{\si@sym@second}
-\newunit{\rperminute}{r/min}
-\newunit{\ton}{t}
-\newunit{\degreecelsius}{\celsius}
-\let\addunit\newunit
-\newcommand*{\addprefix}[2]{\newprefix{#1}{#2}}
-\newcommand*{\si@siu@newunit}[3][]{%
-  \renewcommand*{\si@tempa}{#1}%
-  \renewcommand*{\si@tempb}{square}%
-  \def\si@siu@power{}%
-  \ifx\@empty\si@tempa\@empty\else
-    \ifx\si@tempa\si@tempb
-      \renewcommand*{\si@siu@power}{\ssquare}%
-    \else
-      \edef\si@siu@power{%
-        \expandafter\noexpand\csname #1\endcsname}%
-    \fi
-  \fi
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3\endcsname}%
-  \edef\si@tempb{%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\per
-    \expandafter\noexpand\si@siu@power
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter%
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempb}
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3np\endcsname}%
-  \edef\si@tempb{%
-    \expandafter\noexpand\csname #2\endcsname\noexpand
-    \reciprocal\expandafter\noexpand\si@siu@power
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempb}%
-  \si@siu@newunithook[#1]{#2}{#3}}
-\providecommand*{\si@siu@newunithook}[3][]{}
-\si@siu@newunit{gray}{second}
-\si@siu@newunit[square]{metre}{second}
-\si@siu@newunit{joule}{mole}
-\si@siu@newunit[cubic]{mole}{metre}
-\si@siu@newunit[square]{radian}{second}
-\si@siu@newunit{radian}{second}
-\si@siu@newunit[cubic]{squaremetre}{metre}
-\si@siu@newunit[cubic]{katal}{metre}
-\si@siu@newunit{coulomb}{mol}
-\si@siu@newunit[square]{ampere}{metre}
-\si@siu@newunit[cubic]{kilogram}{metre}
-\si@siu@newunit[cubic]{coulomb}{metre}
-\si@siu@newunit{volt}{metre}
-\si@siu@newunit[square]{coulomb}{squaremetre}
-\si@siu@newunit{farad}{metre}
-\si@siu@newunit[square]{watt}{metre}
-\si@siu@newunit[square]{joule}{metre}
-\si@siu@newunit[cubic]{newton}{metre}
-\si@siu@newunit{newton}{kilogram}
-\si@siu@newunit{joule}{kelvin}
-\si@siu@newunit{joule}{kilogram}
-\si@siu@newunit{coulomb}{kilogram}
-\si@siu@newunit{squaremetre}{second}
-\si@siu@newunit[square]{squaremetre}{second}
-\si@siu@newunit[square]{candela}{metre}
-\si@siu@newunit{ampere}{metre}
-\si@siu@newunit{joule}{tesla}
-\si@siu@newunit{henry}{metre}
-\si@siu@newunit{kilogram}{second}
-\si@siu@newunit[square]{kilogram}{metre}
-\si@siu@newunit{kilogram}{metre}
-\si@siu@newunit[square]{newton}{metre}
-\si@siu@newunit{watt}{kilogram}
-\si@siu@newunit[cubic]{watt}{metre}
-\si@siu@newunit{squaremetre}{kilogram}
-\si@siu@newunit{cubicmetre}{kilogram}
-\si@siu@newunit{newton}{metre}
-\si@siu@newunit[cubic]{squaremetre}{second}
-\si@siu@newunit{metre}{second}
-\si@siu@newunit[cubic]{joule}{metre}
-\si@siu@newunit{cubicmetre}{second}
-\newcommand*{\si@siu@newunitx}[4]{%
-  \expandafter\newunit\expandafter{\csname #1per#2\endcsname}
-    {#3\per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2np\endcsname}
-    {#3\reciprocal#4}
-  \si@siu@newunitxhook{#1}{#2}{#3}{#4}}
-\providecommand*{\si@siu@newunitxhook}[4]{}
-\si@siu@newunitx{kilogramsquaremetre}{second}
-  {\kilogram\squaremetre}{\second}
-\si@siu@newunitx{squaremetre}{newtonsecond}{\squaremetre}
-  {\newton\second}
-\si@siu@newunitx{kilogrammetre}{second}{\kilogram\metre}
-  {\second}
-\si@siu@newunitx{kilogram}{squaremetresecond}{\kilogram}
-  {\squaremetre\second}
-\si@siu@newunitx{joule}{molekelvin}{\joule}{\mole\kelvin}
-\si@siu@newunitx{kilogram}{kilomole}{\kilogram}{\kilo\mole}
-\si@siu@newunitx{kilogrammetre}{squaresecond}{\kilogram\metre}
-  {\second\squared}
-\si@siu@newunitx{watt}{squaremetresteradian}{\watt}
-  {\squaremetre\steradian}
-\si@siu@newunitx{joule}{kilogramkelvin}{\joule}
-  {\kilogram\kelvin}
-\si@siu@newunitx{watt}{metrekelvin}{\watt}{\metre\kelvin}
-\si@siu@newunitx{kilogram}{cubicmetrecoulomb}{\kilogram}
-  {\cubic\metre\coulomb}
-\si@siu@newunitx{kilogram}{secondcubicmetre}{\kilogram}
-  {\second\cubicmetre}
-\newunit{\si@siu@unity}{1}
-\si@siu@newunitx{}{squaremetresecond}{\si@siu@unity}
-  {\squaremetre\second}
-\newunit{\pascalsecond}{\pascal\second}
-\newunit{\amperemetresecond}{\ampere\metre\second}
-\newunit{\ohmmetre}{\ohm\metre}
-\newunit{\newtonmetre}{\newton\metre}
-\let\newtonmetrenp\newtonmetre
-\newunit{\kilogramsquaremetre}{\kilogram\squaremetre}
-\let\kilogramsquaremetrenp\kilogramsquaremetre
-\newcommand*{\si@siu@newprefix}[1]{%
-  \edef\si@tempa{\expandafter\noexpand\csname #1d\endcsname}%
-  \edef\si@tempb{\expandafter\noexpand\csname #1\endcsname}%
-  \expandafter\expandafter\expandafter\newcommand\expandafter
-    \expandafter\expandafter*\expandafter\expandafter
-    \expandafter{\expandafter\si@tempa\expandafter}\expandafter
-      {\expandafter\si@prefixsymbolicfalse\si@tempb}}
-\si@siu@newprefix{yocto}
-\si@siu@newprefix{zepto}
-\si@siu@newprefix{atto}
-\si@siu@newprefix{femto}
-\si@siu@newprefix{pico}
-\si@siu@newprefix{nano}
-\si@siu@newprefix{micro}
-\si@siu@newprefix{milli}
-\si@siu@newprefix{centi}
-\si@siu@newprefix{deca}
-\si@siu@newprefix{deka}
-\si@siu@newprefix{hecto}
-\si@siu@newprefix{kilo}
-\si@siu@newprefix{mega}
-\si@siu@newprefix{giga}
-\si@siu@newprefix{tera}
-\si@siu@newprefix{peta}
-\si@siu@newprefix{exa}
-\si@siu@newprefix{zetta}
-\si@siu@newprefix{yotta}
-\ifsi@old@binary
-  \si@siu@newprefix{kibi}
-  \si@siu@newprefix{mebi}
-  \si@siu@newprefix{gibi}
-  \si@siu@newprefix{tebi}
-  \si@siu@newprefix{pebi}
-  \si@siu@newprefix{exbi}
-\fi
-\ifsi@old@derived
-  \newunit{\derradian}{\metre\reciprocal\metre}
-  \newunit{\dersteradian}{\squaremetre\rpsquare\metre}
-  \newunit{\derhertz}{\reciprocal\second}
-  \newunit{\dernewton}{\metre\kilogram\second\rpsquared}
-  \newunit{\derpascal}{\newton\rpsquare\metre}
-  \newunit{\derjoule}{\newton\metre}
-  \newunit{\derwatt}{\joule\reciprocal\second}
-  \newunit{\dercoulomb}{\ampere\second}
-  \newunit{\dervolt}{\watt\reciprocal\ampere}
-  \newunit{\derfarad}{\coulomb\reciprocal\volt}
-  \newunit{\derohm}{\volt\reciprocal\ampere}
-  \newunit{\dersiemens}{\ampere\reciprocal\volt}
-  \newunit{\derweber}
-    {\squaremetre\kilogram\second\rpsquared\reciprocal\ampere}
-  \newunit{\dertesla}{\weber\rpsquare\metre}
-  \newunit{\derhenry}{\weber\reciprocal\ampere}
-  \newunit{\dercelsius}{\kelvin}
-  \newunit{\derlumen}{\candela\steradian}
-  \newunit{\derlux}{\lumen\rpsquare\metre}
-  \newunit{\derbecquerel}{\derhertz}
-  \newunit{\dergray}{\joule\reciprocal\kilogram}
-  \newunit{\dersievert}{\dergray}
-  \newunit{\derkatal}{\rp\second\usk\mole}
-\fi
-\ifsi@old@derivedinbase
-  \newunit{\radianbase}{\metre\reciprocal\metre}
-  \newunit{\steradianbase}{\squaremetre\rpsquare\metre}
-  \newunit{\hertzbase}{\reciprocal\second}
-  \newunit{\newtonbase}{\metre\kilogram\second\rpsquared}
-  \newunit{\pascalbase}{\reciprocal\metre\kilogram\second%
-    \rpsquared}
-  \newunit{\joulebase}{\squaremetre\kilogram\second\rpsquared}
-  \newunit{\wattbase}{\squaremetre\kilogram\rpcubic\second}
-  \newunit{\coulombbase}{\ampere\second}
-  \newunit{\voltbase}
-    {\squaremetre\kilogram\rpcubic\second\reciprocal\ampere}
-  \newunit{\faradbase}
-    {\rpsquare\metre\reciprocal\kilogram\fourth\second\ampere%
-      \squared}
-  \newunit{\ohmbase}
-    {\squaremetre\kilogram\rpcubic\second\rpsquare\ampere}
-  \newunit{\siemensbase}
-    {\rpsquare\metre\reciprocal\kilogram\cubic\second\ampere%
-       \squared}
-  \newunit{\weberbase}
-    {\squaremetre\kilogram\second\rpsquared\reciprocal\ampere}
-  \newunit{\teslabase}{\kilogram\second\rpsquared\reciprocal%
-     \ampere}
-  \newunit{\henrybase}
-    {\squaremetre\kilogram\second\rpsquared\rpsquare\ampere}
-  \newunit{\celsiusbase}{\kelvin}
-  \newunit{\lumenbase}{\candela\squaremetre\rpsquare\metre}
-  \newunit{\luxbase}{\candela\squaremetre\rpfourth\metre}
-  \newunit{\becquerelbase}{\hertzbase}
-  \newunit{\graybase}{\squaremetre\second\rpsquared}
-  \newunit{\sievertbase}{\graybase}
-  \newunit{\katalbase}{\rp\second\mole}
-\fi
-\InputIfFileExists{SIunits.cfg}
-  {\si@log@inf{SIunits config file loaded}}
-  {\si@log@inf{SIunits config file not found}}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-SIunits.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-UK.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-UK.cfg
deleted file mode 100644
index a750691c66f..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-UK.cfg
+++ /dev/null
@@ -1,49 +0,0 @@
-%%
-%% This is file `si-UK.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `UK')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-UK.cfg}
-  [2010/02/22 v1.4c siunitx: UK locale]
-\sisetup{
-  unitsep=thin,
-  expproduct=times,
-  valuesep=thin,
-  decimalsymbol=fullstop,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-UK.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-ZA.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-ZA.cfg
deleted file mode 100644
index d61cc8b02a6..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-ZA.cfg
+++ /dev/null
@@ -1,49 +0,0 @@
-%%
-%% This is file `si-ZA.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `ZA')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-ZA.cfg}
-  [2010/02/22 v1.4c siunitx: South Africa locale]
-\sisetup{
-  unitsep=cdot,
-  valuesep=thin,
-  expproduct=times,
-  decimalsymbol=comma,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-ZA.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-abbr.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-abbr.cfg
deleted file mode 100644
index a4714d6c512..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-abbr.cfg
+++ /dev/null
@@ -1,98 +0,0 @@
-%%
-%% This is file `si-abbr.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `abbr')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-abbr.cfg}
-  [2010/02/22 v1.4c siunitx: Abbreviated units]
-\requiresiconfigs{prefix,named,accepted,physical}
-\newunit{\pA}{\pico\ampere}
-\newunit{\nA}{\nano\ampere}
-\newunit{\micA}{\micro\ampere}
-\newunit{\mA}{\milli\ampere}
-\newunit{\kA}{\kilo\ampere}
-\newunit{\Hz}{\hertz}
-\newunit{\mHz}{\milli\hertz}
-\newunit{\kHz}{\kilo\hertz}
-\newunit{\MHz}{\mega\hertz}
-\newunit{\GHz}{\giga\hertz}
-\newunit{\THz}{\tera\hertz}
-\newunit{\fmol}{\femto\mole}
-\newunit{\pmol}{\pico\mole}
-\newunit{\nmol}{\nano\mole}
-\newunit{\micmol}{\micro\mole}
-\newunit{\mmol}{\milli\mole}
-\newunit{\kmol}{\kilo\mole}
-\newunit{\kV}{\kilo\volt}
-\newunit{\mV}{\milli\volt}
-\provideunit{\ml}{\milli\litre}
-\provideunit{\micl}{\micro\litre}
-\provideunit{\mL}{\milli\liter}
-\provideunit{\micL}{\micro\liter}
-\newunit{\cmc}{\centi\metre\cubed}
-\newunit{\dmc}{\deci\metre\cubed}
-\newunit{\cms}{\centi\metre\squared}
-\newunit{\kg}{\kilo\gram}
-\AtBeginDocument{\provideunit{\fg}{\femto\gram}}
-\newunit{\SIfg}{\femto\gram}
-\newunit{\pg}{\pico\gram}
-\newunit{\nanog}{\nano\gram}
-\newunit{\micg}{\micro\gram}
-\newunit{\mg}{\milli\gram}
-\newunit{\amu}{\atomicmass}
-\newunit{\kJ}{\kilo\joule}
-\newunit{\eV}{\electronvolt}
-\newunit{\meV}{\milli\electronvolt}
-\newunit{\keV}{\kilo\electronvolt}
-\newunit{\MeV}{\mega\electronvolt}
-\newunit{\GeV}{\giga\electronvolt}
-\newunit{\TeV}{\tera\electronvolt}
-\newunit[unitsep=none]{\kWh}{\kilo\watt\hour}
-\newunit{\picom}{\pico\metre}
-\newunit{\nm}{\nano\metre}
-\newunit{\micm}{\micro\metre}
-\newunit{\mm}{\milli\metre}
-\newunit{\cm}{\centi\metre}
-\newunit{\dm}{\deci\metre}
-\newunit{\km}{\kilo\metre}
-\newunit{\Sec}{\second}
-\newunit{\as}{\atto\second}
-\newunit{\fs}{\femto\second}
-\provideunit{\ps}{\pico\second}
-\newunit{\ns}{\nano\second}
-\newunit{\mics}{\micro\second}
-\newunit{\ms}{\milli\second}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-abbr.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-accepted.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-accepted.cfg
deleted file mode 100644
index 8492a1d6d0f..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-accepted.cfg
+++ /dev/null
@@ -1,64 +0,0 @@
-%%
-%% This is file `si-accepted.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `accepted')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-accepted.cfg}
-  [2010/02/22 v1.4c siunitx: SI Accepted units]
-\newunit{\minute}{min}
-\newunit{\hour}{h}
-\newunit{\Day}{d}
-\newunit{\dday}{d}
-\ifsi@old@OHM
-  \AtBeginDocument{
-    \provideunit[valuesep=none]{\Degree}{\si@sym@degree}
-  }
-\else
-  \ifsi@gensymb\else
-    \AtBeginDocument{
-      \provideunit[valuesep=none]{\degree}{\si@sym@degree}
-    }
-  \fi
-\fi
-\newunit[valuesep=none]{\arcmin}{\si@sym@minute}
-\newunit[valuesep=none]{\arcsec}{\si@sym@second}
-\newunit{\litre}{l}
-\newunit{\liter}{L}
-\newunit{\tonne}{t}
-\newunit{\neper}{Np}
-\newunit{\bel}{B}
-\newunit{\percent}{\char37}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-accepted.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-addn.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-addn.cfg
deleted file mode 100644
index 12fa08637a4..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-addn.cfg
+++ /dev/null
@@ -1,59 +0,0 @@
-%%
-%% This is file `si-addn.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `addn')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-addn.cfg}
-  [2010/02/22 v1.4c siunitx: SI Additional units]
-\provideunit{\angstrom}{\si@sym@ringA}
-\AtBeginDocument{%
-  \ifdefined\Saveangstrom
-    \def\Saveangstrom{\si@sym@ringA}%
-    \def\SaveAngstrom{\si@sym@ringA}%
-  \fi
-}
-\newunit{\are}{a}
-\newunit{\hectare}{\hecto\are}
-\newunit{\barn}{b}
-\newunit{\BAR}{bar}
-\newunit{\bbar}{bar}
-\newunit{\millibar}{\milli\BAR}
-\newunit{\gal}{Gal}
-\newunit{\curie}{Ci}
-\newunit{\roentgen}{R}
-\newunit{\rad}{rad}
-\provideunit{\rem}{rem}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-addn.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-astro.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-astro.cfg
deleted file mode 100644
index e5839f65994..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-astro.cfg
+++ /dev/null
@@ -1,43 +0,0 @@
-%%
-%% This is file `si-astro.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `astro')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-astro.cfg}
-  [2010/02/22 v1.4c siunitx: Units for astronomy]
-\newunit{\parsec}{pc}
-\newunit{\lightyear}{ly}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-astro.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-binary.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-binary.cfg
deleted file mode 100644
index 3feb2cf0443..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-binary.cfg
+++ /dev/null
@@ -1,51 +0,0 @@
-%%
-%% This is file `si-binary.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `binary')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-binary.cfg}
-  [2010/02/22 v1.4c siunitx: Binary units]
-\newprefix[binary]{\kibi}{10}{Ki}
-\newprefix[binary]{\mebi}{20}{Mi}
-\newprefix[binary]{\gibi}{30}{Gi}
-\newprefix[binary]{\tebi}{40}{Ti}
-\newprefix[binary]{\pebi}{50}{Pi}
-\newprefix[binary]{\exbi}{60}{Ei}
-\newprefix[binary]{\zebi}{70}{Zi}
-\newprefix[binary]{\yobi}{80}{Yi}
-\newunit{\bit}{bit}
-\newunit{\byte}{B}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-binary.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-chemeng.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-chemeng.cfg
deleted file mode 100644
index 620620bc0d9..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-chemeng.cfg
+++ /dev/null
@@ -1,44 +0,0 @@
-%%
-%% This is file `si-chemeng.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `chemeng')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-chemeng.cfg}
-  [2010/02/22 v1.4c siunitx: Units for chemical engineering]
-\newunit{\gmol}{g\text{-}mol}
-\newunit{\kgmol}{kg\text{-}mol}
-\newunit{\lbmol}{lb\text{-}mol}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-chemeng.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-fancynum.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-fancynum.cfg
deleted file mode 100644
index f7a940ec760..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-fancynum.cfg
+++ /dev/null
@@ -1,69 +0,0 @@
-%%
-%% This is file `si-fancynum.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `fancynum')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-fancynum.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     fancynum]
-\si@emulating{fancynum}{2000/08/08 0.92}
-\sisetup{decimalsymbol=cdot,digitsep=comma}
-\let\fnum\num
-\newcommand*{\setfnumdsym}[1]{\sisetup{decimalsymbol={#1}}}
-\newcommand*{\setfnumgsym}[1]{\sisetup{digitsep={#1}}}
-\newcommand*{\setfnummsym}[1]{\sisetup{expproduct={#1}}}
-\ifsi@old@english
-  \sisetup{decimalsymbol=cdot,digitsep=comma}
-\fi
-\ifsi@old@french
-  \sisetup{decimalsymbol=comma,digitsep=fullstop}
-\fi
-\ifsi@old@tight
-  \sisetup{expproduct=tighttimes}
-\fi
-\ifsi@old@loose
-  \sisetup{expproduct=times}
-\fi
-\ifsi@old@thinspaces
-  \sisetup{digitsep=thin}
-\fi
-\ifsi@old@commas
-  \sisetup{digitsep=comma}
-\fi
-\ifsi@old@plain
-  \sisetup{digitsep=none}
-\fi
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-fancynum.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-fancyunits.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-fancyunits.cfg
deleted file mode 100644
index 25d26baf616..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-fancyunits.cfg
+++ /dev/null
@@ -1,127 +0,0 @@
-%%
-%% This is file `si-fancyunits.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `fancyunits')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-fancyunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     fancyunits]
-\si@emulating{fancyunits}{2007/02/01 v1.0.1}
-\si@ifloaded{SIunits}
-  {\si@log@err{SIunits emulation loaded\MessageBreak before
-    fancyunits emulation}{You need to load the fancyunits
-    emualtion\MessageBreak code before that for
-    SIunits.\MessageBreak Try emulate=fancyunits as the first
-    option when\MessageBreak loading siunitx}}{}
-\newcommand*{\si@siu@newunithook}[3][]{%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3uf\endcsname}%
-  \renewcommand*{\si@tempb}{stickyper,per=fraction,
-    fraction=nice}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3Uf\endcsname}%
-  \renewcommand*{\si@tempb}{stickyper,per=fraction,
-    fraction=frac}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \noexpand\def\noexpand\si@frc@hook{\noexpand\textstyle}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}%
-  \edef\si@tempa{%
-    \expandafter\noexpand\csname #2per#1#3UF\endcsname}%
-  \edef\si@tempc{%
-    \noexpand\sisetup{\si@tempb}%
-    \noexpand\def\noexpand\si@frc@hook{\noexpand\displaystyle}%
-    \expandafter\noexpand\csname #2\endcsname\noexpand\si@per%
-    \expandafter\noexpand\si@siu@power%
-    \expandafter\noexpand\csname #3\endcsname}%
-  \expandafter\expandafter\expandafter\newunit\expandafter
-    \expandafter\expandafter{\expandafter\si@tempa\expandafter}%
-      \expandafter{\si@tempc}}
-\newcommand*{\si@siu@newunitxhook}[4]{%
-  \expandafter\newunit\expandafter{\csname #1per#2uf\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=nice}%
-     #3\si@per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2Uf\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=frac}%
-     \renewcommand*{\si@frc@hook}{\textstyle}%
-     #3\si@per#4}%
-  \expandafter\newunit\expandafter{\csname #1per#2UF\endcsname}
-    {\sisetup{stickyper,per=fraction,fraction=frac}%
-     \renewcommand*{\si@frc@hook}{\displaystyle}%
-     #3\si@per#4}}
-\requiresiconfigs{SIunits,addn,astro}
-\sisetup{obeyall}
-\ifsi@old@spaceqspace
-  \sisetup{valuesep=space}
-\fi
-\newunit{\paminute}{'}
-\newunit{\parsecond}{''}
-\newunit{\AstroE}{AE}
-\newunit{\oersted}{OE}
-\provideunit{\ton}{t}
-\let\decaD\decad
-\newcommand*{\ufrac}[2]{%
-  \si[stickyper,per=fraction,fraction=nice]{#1\si@per#2}}
-\newcommand*{\Ufrac}[2]{%
-  \ensuremath{\textstyle{%
-    \si[stickyper,per=fraction,fraction=frac]{#1\si@per#2}}}}
-\newcommand*{\UFrac}[2]{%
-  \ensuremath{\displaystyle{%
-    \si[stickyper,per=fraction,fraction=frac]{#1\si@per#2}}}}
-\let\pow\power
-\let\Squaremetre\squaremetre
-\si@siu@newunit{Gray}{second}
-\si@siu@newunit[square]{Squaremetre}{metre}
-\si@siu@newunitx{Squaremetre}{newtonsecond}{\Square\metre}
-  {\newton\second}
-\si@siu@newunit{Squaremetre}{second}
-\si@siu@newunit[square]{Squaremetre}{squaresecond}
-\si@siu@newunit{Squaremetre}{kilogram}
-\si@siu@newunit[cubic]{Squaremetre}{second}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-fancyunits.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-geophys.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-geophys.cfg
deleted file mode 100644
index 8b62aa11907..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-geophys.cfg
+++ /dev/null
@@ -1,42 +0,0 @@
-%%
-%% This is file `si-geophys.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `geophys')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-geophys.cfg}
-  [2010/02/22 v1.4c siunitx: Units for astronomy]
-\newunit{\gon}{gon}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-geophys.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-hep.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-hep.cfg
deleted file mode 100644
index 63c80359f3a..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-hep.cfg
+++ /dev/null
@@ -1,59 +0,0 @@
-%%
-%% This is file `si-hep.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `hep')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-hep.cfg}
-  [2010/02/22 v1.4c siunitx: Units for high-energy physics]
-\requiresiconfigs{prefix,named}
-\provideunit{\micron}{\micro\metre}
-\newunit{\mrad}{\milli\rad}
-\newunit{\gauss}{G}
-\newunit{\clight}{\ensuremath{\mathnormal{c}}}
-\newunit{\eVperc}{\eV\per\clight}
-\newunit{\nanobarn}{\nano\barn}
-\newunit{\picobarn}{\pico\barn}
-\newunit{\femtobarn}{\femto\barn}
-\newunit{\attobarn}{\atto\barn}
-\newunit{\zeptobarn}{\zepto\barn}
-\newunit{\yoctobarn}{\yocto\barn}
-\provideunit{\nb}{\nano\barn}
-\provideunit{\pb}{\pico\barn}
-\provideunit{\fb}{\femto\barn}
-\provideunit{\ab}{\atto\barn}
-\provideunit{\zb}{\zepto\barn}
-\provideunit{\yb}{\yocto\barn}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-hep.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-hepunits.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-hepunits.cfg
deleted file mode 100644
index b6aa8527901..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-hepunits.cfg
+++ /dev/null
@@ -1,92 +0,0 @@
-%%
-%% This is file `si-hepunits.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `hepunits')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-hepunits.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     hepunits]
-\si@emulating{hepunits}{2007/09/27}
-\requiresiconfigs{SIunits,accepted,prefix,hep}
-\ifsi@old@noprefixcmds\else
-  \newunit{\invbarn}{\per\barn}
-  \newunit{\invnanobarn}{\per\nano\barn}
-  \newunit{\invpicobarn}{\per\pico\barn}
-  \newunit{\invfemtobarn}{\per\femto\barn}
-  \newunit{\invattobarn}{\per\atto\barn}
-  \newunit{\invzeptobarn}{\per\zepto\barn}
-  \newunit{\invyoctobarn}{\per\yocto\barn}
-  \newunit{\invnb}{\per\nano\barn}
-  \newunit{\invpb}{\per\pico\barn}
-  \newunit{\invfb}{\per\femto\barn}
-  \newunit{\invab}{\per\atto\barn}
-  \newunit{\invzb}{\per\zepto\barn}
-  \newunit{\invyb}{\per\yocto\barn}
-\fi
-\newunit{\invcmsqpersecond}{\per\Square\centi\metre\per\second}
-\newunit{\invcmsqpersec}{\per\Square\centi\metre\per\second}
-\newunit{\lumiunits}{\per\Square\centi\metre\per\second}
-\newunit{\inveV}{\per\electronvolt}
-\newunit{\minveV}{\per\milli\electronvolt}
-\newunit{\kinveV}{\per\kilo\electronvolt}
-\newunit{\MinveV}{\per\mega\electronvolt}
-\newunit{\GinveV}{\per\giga\electronvolt}
-\newunit{\TinveV}{\per\tera\electronvolt}
-\newunit[per=slash,eVcorrb=0.6ex]{\eVoverc}
-  {\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\eVovercsq}
-  {\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\meVoverc}
-  {\milli\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\keVoverc}
-  {\kilo\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\MeVoverc}
-  {\mega\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\GeVoverc}
-  {\giga\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\TeVoverc}
-  {\tera\electronvolt\per\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\meVovercsq}
-  {\milli\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\keVovercsq}
-  {\kilo\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\MeVovercsq}
-  {\mega\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\GeVovercsq}
-  {\giga\electronvolt\per\Square\clight}
-\newunit[per=slash,eVcorrb=0.6ex]{\TeVovercsq}
-  {\tera\electronvolt\per\Square\clight}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-hepunits.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-named.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-named.cfg
deleted file mode 100644
index 0469bfd3144..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-named.cfg
+++ /dev/null
@@ -1,77 +0,0 @@
-%%
-%% This is file `si-named.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `named')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-named.cfg}
-  [2010/02/22 v1.4c siunitx: SI Named units]
-\newunit{\becquerel}{Bq}
-\newunit{\coulomb}{C}
-\newunit{\farad}{F}
-\newunit{\Gray}{Gy}
-\newunit{\ggray}{Gy}
-\newunit{\hertz}{Hz}
-\newunit{\henry}{H}
-\newunit{\joule}{J}
-\newunit{\katal}{kat}
-\newunit{\lumen}{lm}
-\newunit{\lux}{lx}
-\newunit{\newton}{N}
-\ifsi@old@OHM
-  \newunit{\Ohm}{\si@sym@Omega}
-\else
-  \ifsi@gensymb\else
-    \provideunit{\ohm}{\si@sym@Omega}
-  \fi
-\fi
-\newunit{\pascal}{Pa}
-\newunit{\siemens}{S}
-\newunit{\sievert}{Sv}
-\newunit{\tesla}{T}
-\newunit{\volt}{V}
-\newunit{\watt}{W}
-\newunit{\weber}{Wb}
-\ifsi@old@OHM
-  \newunit{\Celsius}{\si@sym@celsius}
-\else
-  \ifsi@gensymb\else
-    \newunit{\celsius}{\si@sym@celsius}
-  \fi
-\fi
-\newunit\degreeCelsius{\si@sym@celsius}
-\newunit{\radian}{rad}
-\newunit{\steradian}{sr}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-named.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-physical.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-physical.cfg
deleted file mode 100644
index 79da81cf1ad..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-physical.cfg
+++ /dev/null
@@ -1,47 +0,0 @@
-%%
-%% This is file `si-physical.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `physical')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-physical.cfg}
-  [2010/02/22 v1.4c siunitx: SI Physically-measured units]
-\newcommand*{\si@eVspacea}{\text{\kern-\si@eVcorra}}%
-\newcommand*{\si@eVspaceb}{\text{\kern-\si@eVcorrb}}%
-\newunit{\electronvolt}{e\protect\si@eVspacea V\protect%
-  \si@eVspaceb}
-\newunit{\atomicmass}{u}
-\newunit{\atomicmassunit}{u}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-physical.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-prefix.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-prefix.cfg
deleted file mode 100644
index b006a92d2b2..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-prefix.cfg
+++ /dev/null
@@ -1,70 +0,0 @@
-%%
-%% This is file `si-prefix.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `prefix')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-prefix.cfg}
-  [2010/02/22 v1.4c siunitx: SI Multiple prefixes]
-\newprefix{\yocto}{-24}{y}
-\newprefix{\zepto}{-21}{z}
-\newprefix{\atto}{-18}{a}
-\newprefix{\femto}{-15}{f}
-\newprefix{\pico}{-12}{p}
-\newprefix{\nano}{-9}{n}
-\ifsi@old@OHM
-  \newprefix{\Micro}{-6}{\si@sym@mu}
-\else
-  \ifsi@gensymb\else
-    \newprefix{\micro}{-6}{\si@sym@mu}
-  \fi
-\fi
-\newprefix{\milli}{-3}{m}
-\newprefix{\centi}{-2}{c}
-\newprefix{\deci}{-1}{d}
-\newprefix{\deca}{1}{da}
-\newprefix{\hecto}{2}{h}
-\newprefix{\kilo}{3}{k}
-\newprefix{\mega}{6}{M}
-\newprefix{\giga}{9}{G}
-\newprefix{\tera}{12}{T}
-\newprefix{\peta}{15}{P}
-\newprefix{\exa}{18}{E}
-\newprefix{\zetta}{21}{Z}
-\newprefix{\yotta}{24}{Y}
-\newprefix{\deka}{1}{da}
-\newunit{\gram}{g}
-\renewunit{\kilogram}{\kilo\gram}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-prefix.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-prefixed.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-prefixed.cfg
deleted file mode 100644
index a970a3ba2e5..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-prefixed.cfg
+++ /dev/null
@@ -1,126 +0,0 @@
-%%
-%% This is file `si-prefixed.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `prefixed')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-prefixed.cfg}
-  [2010/02/22 v1.4c siunitx: SI Prefixed units]
-\requiresiconfigs{prefix,named,accepted,physical}
-\newunit{\picometre}{\pico\metre}
-\newunit{\nanometre}{\nano\metre}
-\newunit{\micrometre}{\micro\metre}
-\newunit{\millimetre}{\milli\metre}
-\newunit{\centimetre}{\centi\metre}
-\newunit{\decimetre}{\deci\metre}
-\newunit{\kilometre}{\kilo\metre}
-\newunit{\femtogram}{\femto\gram}
-\newunit{\picogram}{\pico\gram}
-\newunit{\nanogram}{\nano\gram}
-\newunit{\microgram}{\micro\gram}
-\newunit{\milligram}{\milli\gram}
-\newunit{\femtomole}{\femto\mole}
-\newunit{\picomole}{\pico\mole}
-\newunit{\nanomole}{\nano\mole}
-\newunit{\micromole}{\micro\mole}
-\newunit{\millimole}{\milli\mole}
-\newunit{\kilomole}{\kilo\mole}
-\newunit{\attosecond}{\atto\second}
-\newunit{\femtosecond}{\femto\second}
-\newunit{\picosecond}{\pico\second}
-\newunit{\nanosecond}{\nano\second}
-\newunit{\microsecond}{\micro\second}
-\newunit{\millisecond}{\milli\second}
-\newunit{\picoampere}{\pico\ampere}
-\newunit{\nanoampere}{\nano\ampere}
-\newunit{\microampere}{\micro\ampere}
-\newunit{\milliampere}{\milli\ampere}
-\newunit{\kiloampere}{\kilo\ampere}
-\newunit{\millivolt}{\milli\volt}
-\newunit{\kilovolt}{\kilo\volt}
-\newunit{\milliwatt}{\milli\watt}
-\newunit{\kilowatt}{\kilo\watt}
-\newunit{\megawatt}{\mega\watt}
-\newunit{\femtofarad}{\femto\farad}
-\newunit{\picofarad}{\pico\farad}
-\newunit{\nanofarad}{\nano\farad}
-\newunit{\microfarad}{\micro\farad}
-\newunit{\millifarad}{\milli\farad}
-\newunit{\millisiemens}{\milli\siemens}
-\ifsi@old@OHM
-  \newunit{\kilohm}{\kilo\Ohm}
-  \newunit{\megohm}{\mega\Ohm}
-  \newunit{\gigaohm}{\giga\Ohm}
-\else
-  \ifsi@gensymb\else
-  \newunit{\kilohm}{\kilo\ohm}
-  \newunit{\megohm}{\mega\ohm}
-  \newunit{\gigaohm}{\giga\ohm}
-  \fi
-\fi
-\newunit{\microlitre}{\micro\litre}
-\newunit{\millilitre}{\milli\litre}
-\newunit{\microliter}{\micro\liter}
-\newunit{\milliliter}{\milli\liter}
-\newunit{\cubicmetre}{\metre\cubed}
-\newunit{\cubiccentimetre}{\centi\metre\cubed}
-\newunit{\centimetrecubed}{\centi\metre\cubed}
-\newunit{\cubicmicrometre}{\micro\metre\cubed}
-\newunit{\cubicmillimetre}{\milli\metre\cubed}
-\newunit{\cubicdecimetre}{\cubic\deci\metre}
-\newunit{\squaremetre}{\Square\metre}
-\newunit{\squarecentimetre}{\Square\centi\metre}
-\newunit{\centimetresquared}{\centi\metre\squared}
-\newunit{\squarekilometre}{\Square\kilo\metre}
-\newunit{\millijoule}{\milli\joule}
-\newunit{\kilojoule}{\kilo\joule}
-\newunit{\megajoule}{\mega\joule}
-\newunit{\millielectronvolt}{\milli\electronvolt}
-\newunit{\kiloelectronvolt}{\kilo\electronvolt}
-\newunit{\megaelectronvolt}{\mega\electronvolt}
-\newunit{\gigaelectronvolt}{\giga\electronvolt}
-\newunit{\teraelectronvolt}{\tera\electronvolt}
-\newunit[unitsep=none]{\kilowatthour}{\kilo\watt\hour}
-\newunit{\millihertz}{\milli\hertz}
-\newunit{\kilohertz}{\kilo\hertz}
-\newunit{\megahertz}{\mega\hertz}
-\newunit{\gigahertz}{\giga\hertz}
-\newunit{\terahertz}{\tera\hertz}
-\newunit{\millinewton}{\milli\newton}
-\newunit{\kilonewton}{\kilo\newton}
-\newunit{\hectopascal}{\hecto\pascal}
-\newunit{\megabecquerel}{\mega\becquerel}
-\newunit{\millisievert}{\milli\sievert}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-prefixed.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-sistyle.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-sistyle.cfg
deleted file mode 100644
index d7bee0542b3..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-sistyle.cfg
+++ /dev/null
@@ -1,108 +0,0 @@
-%%
-%% This is file `si-sistyle.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `sistyle')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-sistyle.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of
-     SIstyle]
-\si@emulating{sistyle}{2006/12/20 v2.3}
-\sisetup{%
-  sepfour=true,
-  obeyfamily,
-  obeyitalic=true,
-  numsign=+-,
-  strictarc=false,
-  unitsep=cdot}
-\newcommand*{\SIobeyboldtrue}{\sisetup{obeybold=true}}
-\newcommand*{\SIobeyboldfalse}{\sisetup{obeybold=false}}
-\let\num\relax
-\si@newrobustcmd*{\num}{%
-  \@ifstar
-    {\si@sis@numstar}
-    {\si@sis@num}}
-\newcommand*{\si@sis@num}[2][]{%
-  \begingroup%
-    \sisetup{#1}%
-    \expandafter\si@out@num\expandafter{\si@num{#2}}%
-  \endgroup}
-\newcommand*{\si@sis@numstar}[2][]{%
-  \begingroup%
-    \sisetup{mode=text,obeybold}%
-    \sisetup{#1}%
-    \expandafter\si@out@num\expandafter{\si@num{#2}}%
-  \endgroup}
-\newcommand*{\pnt}{\ensuremath{\si@decimalsymbol}}
-\newcommand*{\SIgroupfourtrue}{\sisetup{sepfour=true}}
-\newcommand*{\SIgroupfourfalse}{\sisetup{sepfour=false}}
-\newcommand*{\SIunitsep}[1]{\sisetup{valuesep={#1}}}
-\newcommand*{\SIunitspace}[1]{\sisetup{unitspace={#1}}}
-\newcommand*{\SIunitdot}[1]{\sisetup{unitsep={#1}}}
-\newcommand*{\SIdecimalsymbol}[1]{\sisetup{decimalsymbol={#1}}}
-\newcommand*{\SIthousandsep}[1]{\sisetup{digitsep={#1}}}
-\newcommand*{\SIproductsign}[1]{\sisetup{expproduct={#1}}}
-\newcommand*{\SIdecimalsign}[1]{\sisetup{decimalsymbol={#1}}}
-\newcommand*{\si@sis@savefont}[2]{%
-  \@namedef{si@sis@#1}{#2}%
-  \sisetup{#1=si@sis@#1}}
-\newcommand*{\SImathrm}[1]{\si@sis@savefont{mathrm}{#1}}
-\newcommand*{\SImathsf}[1]{\si@sis@savefont{mathsf}{#1}}
-\newcommand*{\SImathtt}[1]{\si@sis@savefont{mathtt}{#1}}
-\newcommand*{\SIdefaultMfam}[1]{\si@sis@savefont{mathrm}{#1}}
-\newcommand*{\SIdefaultNfam}[1]{\si@sis@savefont{mathnumrm}{#1}}
-\newcommand*{\SIdefaultTfam}[1]{\si@sis@savefont{textrm}{#1}}
-\si@newrobustcmd*{\ensureupmath}[1]{%
-  \begingroup
-    \sisetup{mode=maths,obeyitalic=false}%
-    \si@out{#1}%
-  \endgroup}
-\newcommand*{\degC}{\si@sym@celsius}
-\newcommand*{\arcdeg}{\si@sym@degree}
-\newcommand*{\degF}{\si@sym@degree F}
-\newcommand*{\SIstyle}[1]{\sisetup{locale=#1}}
-\newcommand*{\SIstyleToLang}[2]{\sisetup{loctolang=#1:#2}}
-\newcommand*{\AddToSIstyle}{%
-  \si@switchfalse
-  \@ifstar
-    {\si@switchtrue
-     \si@sis@addtolocale}
-    {\si@sis@addtolocale}}
-\newcommand*{\si@sis@addtolocale}[2]{%
-  \ifsi@switch
-    \expandafter\let\csname si@loc@#1@extra\endcsname\relax
-  \fi
-  \addtolocale{#1}{#2}}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-sistyle.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-synchem.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-synchem.cfg
deleted file mode 100644
index 293072a53ff..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-synchem.cfg
+++ /dev/null
@@ -1,47 +0,0 @@
-%%
-%% This is file `si-synchem.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `synchem')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-synchem.cfg}
-  [2010/02/22 v1.4c siunitx: Units for synthetic chemists]
-\requiresiconfigs{prefix}
-\newunit{\mmHg}{mmHg}
-\newunit{\molar}{\mole\per\cubic\deci\metre}
-\newunit{\Molar}{\textsc{m}}
-\newunit{\torr}{Torr}
-\newunit{\dalton}{Da}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-synchem.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-units.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-units.cfg
deleted file mode 100644
index f86e99ddd25..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-units.cfg
+++ /dev/null
@@ -1,74 +0,0 @@
-%%
-%% This is file `si-units.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `units')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\si@ifloaded{units}{\endinput}{}
-\ProvidesFile{si-units.cfg}
-  [2010/02/22 v1.4c siunitx: Emulation of units]
-\si@emulating{units}{1998/08/04 v0.9b}
-\si@ifloaded{SIunits}
-  {\si@emclash{units}{SIunits}\endinput}{}
-\si@ifloaded{sistyle}
-  {\si@emclash{units}{sistyle}\endinput}{}
-\sisetup{per=fraction,fraction=nice,obeybold,inlinebold=maths,
-  ,obeymode}
-\ifsi@old@tight
-  \sisetup{valuesep=thin}
-\fi
-\ifsi@old@loose
-  \sisetup{valuesep=space}
-\fi
-\ifsi@old@ugly
-  \sisetup{fraction=ugly}
-\fi
-\si@newrobustcmd*{\unit}[2][]{%
-  \ifmmode
-    \SI{#1}{#2}%
-  \else
-    \SI[obeyfamily,obeyitalic]{#1}{#2}%
-  \fi}
-\si@newrobustcmd*{\unitfrac}[3][]{%
-  \begingroup
-    \si@fam@mode%
-    \ifmmode\else
-      \sisetup{obeyfamily,obeyitalic}%
-    \fi
-    \si@ifnotmtarg{#1}
-      {\num{#1}\ensuremath{\si@valuesep}}%
-    \si@frac{#2}{#3}
-  \endgroup}
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-units.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-unitsdef.cfg b/Master/texmf-dist/tex/latex/siunitx/config/si-unitsdef.cfg
deleted file mode 100644
index eba83cb0606..00000000000
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-unitsdef.cfg
+++ /dev/null
@@ -1,254 +0,0 @@
-%%
-%% This is file `si-unitsdef.cfg',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% siunitx.dtx  (with options: `unitsdef')
-%% ---------------------------------------------------------------
-%% The siunitx package --- A comprehensive (SI) units package
-%% Maintained by Joseph Wright
-%% E-mail: joseph.wright@morningstar2.co.uk
-%% Released under the LaTeX Project Public License v1.3c or later
-%% See http://www.latex-project.org/lppl.txt
-%% ---------------------------------------------------------------
-%% 
-\ProvidesFile{si-unitsdef.cfg}
-  [2010/02/22 v1.4c siunitx:
-   Emulation of unitsdef]
-\si@emulating{unitsdef}{2005/01/04 v0.2}
-\si@ifloaded{SIunits}
-  {\si@emclash{unitsdef}{SIunits}\endinput}{}
-\si@ifloaded{sistyle}
-  {\si@emclash{unitsdef}{sistyle}\endinput}{}
-\requiresiconfigs{units}
-\RequirePackage{textcomp}
-\RequirePackage[T1]{fontenc}
-\sisetup{mode=text,allowoptarg,prespace}
-\ifsi@old@noxspace
-  \sisetup{xspace=false}
-\fi
-\ifsi@old@noabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nofrequncyabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nomolabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@novoltageabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@novolumeabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@noweightabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@noenergyabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@nolengthabbr
-  \sisetup{noload=abbr}
-\fi
-\ifsi@old@notimeabbr
-  \sisetup{noload=abbr}
-\fi
-\newcommand*{\unitvaluesep}{\,}
-\renewcommand*{\si@valuesep}{\text{\unitvaluesep}}
-\define@choicekey*+[si]{key}{valuesep}[\si@tempa]
-  {space,thin,med,medium,thick,none}
-  {\renewcommand*\unitvaluesep\@nameuse{si@fix@##1}%
-   \si@log@debug{Option valuesep set to ##1}}
-  {\si@log@debug{Option valuesep set to ##1}%
-   \renewcommand*\unitvaluesep{##1}}
-\let\unitsignonly\si
-\si@newrobustcmd*{\ilu}[2][]{%
-  \begingroup
-    #1\unitvaluesep%
-    \unit{#2}%
-  \endgroup}
-\let\arc\ang
-\newcommand*{\unitSIdef}{\upshape}
-\newcommand*{\si@unitSIdef}{\unitSIdef\selectfont}
-\sisetup{textrm=si@unitSIdef}
-\let\per\relax
-\si@newrobustcmd*{\per}[2]{%
-  \begingroup
-    \si@xspacefalse
-    \renewcommand*{\unitvaluesep}{}%
-    \unitfrac{#1}{#2}%
-  \endgroup}
-\newcommand*{\unittimes}{\ensuremath{\cdot}}
-\newcommand*{\unitsep}{\,}
-\renewcommand*{\si@unt@unithook}{\si@unt@litouttrue}
-\sisetup{unitsep=none}
-\newcommand*{\unitsuperscript}{\tothe}
-\newcommand*{\newnosepunit}{\newunit[valuesep=none]}
-\newcommand*{\renewnosepunit}{\renewunit[valuesep=none]}
-\newcommand*{\setTextOmega}[2]{%
-  \renewcommand*{\si@textOmega}{%
-      \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathOmega}[1]{\sisetup{mathsOmega=#1}}
-\newcommand*{\setTextmu}[2]{%
-  \renewcommand*{\si@textmu}{%
-    \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathmu}[1]{\sisetup{mathsmu=#1}}
-\newcommand*{\setTextCelsius}[2]{%
-  \renewcommand*{\si@textcelsius}{%
-    \begingroup
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setMathCelsius}[1]{\sisetup{mathscelsius=#1}}
-\newcommand*{\setMathDegree}[2]{%
-  \renewcommand*{\si@textdegree}{%
-    \begingroup%
-      \edef\si@tempa{\sfdefault}%
-      \ifx\f@family\si@tempa
-        \expandafter#2%
-      \else
-        \expandafter#1%
-      \fi
-    \endgroup}}
-\newcommand*{\setTextDegree}[1]{\sisetup{textdegree=#1}}
-\ifsi@old@OHM
-  \ifsi@old@ohm
-    \si@log@inf{Both `ohm' and `OHM' options given\MessageBreak
-      Using default behaviour for unitsdef}
-    \expandafter\expandafter\expandafter\si@old@OHMfalse
-  \fi
-\fi
-\ifsi@old@liter
-  \ifsi@old@LITER
-    \si@log@inf{Both `liter' and `LITER' options
-      given\MessageBreak Using default behaviour for unitsdef}
-  \else
-    \renewunit{\liter}{l}
-  \fi
-\fi
-\newunit{\ton}{t}
-\newunit{\days}{d}
-\newunit{\picometer}{\pico\meter}
-\newunit{\nanometer}{\nano\meter}
-\newunit{\micrometer}{\micro\meter}
-\newunit{\millimeter}{\milli\meter}
-\newunit{\centimeter}{\centi\meter}
-\newunit{\decimeter}{\deci\meter}
-\newunit{\kilometer}{\kilo\meter}
-\newunit{\femtoliter}{\femto\liter}
-\newunit{\picoliter}{\pico\liter}
-\newunit{\nanoliter}{\nano\liter}
-\newunit{\microliter}{\micro\liter}
-\newunit{\milliliter}{\milli\liter}
-\newunit{\centiliter}{\centi\liter}
-\newunit{\deciliter}{\deci\liter}
-\newunit{\hectoliter}{\hecto\liter}
-\newunit{\cubicmeter}{\meter\cubed}
-\newunit{\cubicmicrometer}{\micro\meter\cubed}
-\newunit{\cubicmillimeter}{\milli\meter\cubed}
-\newunit{\squaremeter}{\Square\meter}
-\newunit{\squarecentimeter}{\Square\centi\meter}
-\newunit{\squarekilometer}{\Square\kilo\meter}
-\newunit{\ar}{a}
-\newunit{\hectar}{\hecto\ar}
-\ifsi@old@noabbr
-\else
-  \ifsi@old@novoltageabbr\else
-    \newunit{\kv}{\kilo\volt}
-    \newunit{\mv}{\milli\volt}
-  \fi
-\fi
-\ifsi@old@noabbr\else
-  \ifsi@old@notimeabbr\else
-    \newunit{\sek}{\second}
-  \fi
-  \ifsi@old@noweightabbr\else
-    \newunit{\fg}{\femto\gram}
-  \fi
-  \ifsi@old@novolumeabbr\else
-    \newunit{\fl}{\femto\liter}
-    \newunit{\pl}{\pico\liter}
-    \newunit{\nl}{\nano\liter}
-    \newunit{\micl}{\micro\liter}
-    \newunit{\ml}{\milli\liter}
-    \newunit{\cl}{\centi\liter}
-    \newunit{\dl}{\deci\liter}
-    \newunit{\hl}{\hecto\liter}
-  \fi
-\fi
-\newunit{\calory}{cal}
-\newunit{\kilocalory}{\kilo\calory}
-\newunit{\uBar}{ba}
-\catcode`\-=11\relax
-\ifsi@old@redef-gensymb
-  \expandafter\si@gensymbtrue
-\fi
-\catcode`\-=12\relax
-\ifsi@gensymb
-  \RequirePackage{gensymb}
-  \AtBeginDocument{
-    \let\gensymbohm\ohm
-    \let\gensymbcelsius\celsius
-    \let\gensymbmicro\micro
-    \let\gensymbdegree\degree
-    \let\ohm\@undefined
-    \let\celsius\@undefined
-    \let\micro\@undefined
-    \let\degree\@undefined
-    \ifsi@old@OHM\else
-      \newunit{\ohm}{\si@sym@Omega}
-      \newunit{\celsius}{\si@sym@celsius}
-      \newprefix{\micro}{\si@sym@mu}{-6}
-      \newunit{\degree}{\si@sym@degree}
-    \fi}
-\fi
-\requiresiconfigs{prefix,named,addn,accepted}
-\ifsi@old@noconfig\else
-  \InputIfFileExists{unitsdef.cfg}
-    {\si@log@inf{unitsdef config file loaded}}
-    {\si@log@inf{unitsdef config file not found}}
-\fi
-%% 
-%% Copyright (C) 2008-2010 by
-%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
-%% 
-%% It may be distributed and/or modified under the conditions of
-%% the LaTeX Project Public License (LPPL), either version 1.3c of
-%% this license or (at your option) any later version.  The latest
-%% version of this license is in the file:
-%% 
-%%    http://www.latex-project.org/lppl.txt
-%% 
-%% This work is "maintained" (as per LPPL maintenance status) by
-%%   Joseph Wright.
-%% 
-%% This work consists of the file  siunitx.dtx
-%%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
-%% 
-%%
-%% End of file `si-unitsdef.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/siunitx-abbreviations.cfg b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-abbreviations.cfg
new file mode 100644
index 00000000000..d4d787aeb34
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-abbreviations.cfg
@@ -0,0 +1,92 @@
+%%
+%% This is file `siunitx-abbreviations.cfg',
+%% generated with the docstrip utility.
+%%
+%% The original source files were:
+%%
+%% siunitx.dtx  (with options: `config,abbreviations')
+%% ---------------------------------------------------------------
+%% The siunitx package --- A comprehensive (SI) units package
+%% Maintained by Joseph Wright
+%% E-mail: joseph.wright@morningstar2.co.uk
+%% Released under the LaTeX Project Public License v1.3c or later
+%% See http://www.latex-project.org/lppl.txt
+%% ---------------------------------------------------------------
+%% 
+\ProvidesExplFile {siunitx-abbreviations.cfg} {2010/05/23} {2.0}
+  {siunitx: Abbreviated units}
+\DeclareSIUnit \pA { \pico  \ampere }
+\DeclareSIUnit \nA { \nano  \ampere }
+\DeclareSIUnit \uA { \micro \ampere }
+\DeclareSIUnit \mA { \milli \ampere }
+\DeclareSIUnit \kA { \kilo  \ampere }
+\DeclareSIUnit \Hz  {        \hertz }
+\DeclareSIUnit \mHz { \milli \hertz }
+\DeclareSIUnit \kHz { \kilo  \hertz }
+\DeclareSIUnit \MHz { \mega  \hertz }
+\DeclareSIUnit \GHz { \giga  \hertz }
+\DeclareSIUnit \THz { \tera  \hertz }
+\DeclareSIUnit \fmol { \femto \mole }
+\DeclareSIUnit \pmol { \pico  \mole }
+\DeclareSIUnit \nmol { \nano  \mole }
+\DeclareSIUnit \umol { \micro \mole }
+\DeclareSIUnit \mmol { \milli \mole }
+\DeclareSIUnit \kmol { \kilo  \mole }
+\DeclareSIUnit \mV { \milli \volt }
+\DeclareSIUnit \kV { \kilo  \volt }
+\DeclareSIUnit \ml { \milli \litre }
+\DeclareSIUnit \ul { \micro \litre }
+\DeclareSIUnit \mL { \milli \liter }
+\DeclareSIUnit \uL { \micro \liter }
+\DeclareSIUnit \fg  { \femto \gram }
+\DeclareSIUnit \pg  { \pico  \gram }
+\DeclareSIUnit \ng  { \nano  \gram }
+\DeclareSIUnit \ug  { \micro \gram }
+\DeclareSIUnit \mg  { \milli \gram }
+\DeclareSIUnit \g   { \gram }
+\DeclareSIUnit \kg  { \kilo \gram }
+\DeclareSIUnit \amu { \atomicmassunit }
+\DeclareSIUnit \kJ  { \kilo \joule }
+\DeclareSIUnit \eV  { \electronvolt }
+\DeclareSIUnit \meV { \milli \electronvolt }
+\DeclareSIUnit \keV { \kilo  \electronvolt }
+\DeclareSIUnit \MeV { \mega  \electronvolt }
+\DeclareSIUnit \GeV { \giga  \electronvolt }
+\DeclareSIUnit \TeV { \tera  \electronvolt }
+\DeclareSIUnitWithOptions \kWh { \kilo \watt \hour }
+  { inter-unit-separator = }
+\DeclareSIUnit \nm { \nano  \metre }
+\DeclareSIUnit \pm { \pico  \metre }
+\DeclareSIUnit \um { \micro \metre }
+\DeclareSIUnit \mm { \milli \metre }
+\DeclareSIUnit \cm { \centi \metre }
+\DeclareSIUnit \dm { \deci  \metre }
+\DeclareSIUnit \km { \kilo  \metre }
+\DeclareSIUnit \s  { \second }
+\DeclareSIUnit \as { \atto  \second }
+\DeclareSIUnit \fs { \femto \second }
+\DeclareSIUnit \ps { \pico  \second }
+\DeclareSIUnit \ns { \nano  \second }
+\DeclareSIUnit \us { \micro \second }
+\DeclareSIUnit \ms { \milli \second }
+%% 
+%% Copyright (C) 2008-2010 by
+%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
+%% 
+%% It may be distributed and/or modified under the conditions of
+%% the LaTeX Project Public License (LPPL), either version 1.3c of
+%% this license or (at your option) any later version.  The latest
+%% version of this license is in the file:
+%% 
+%%    http://www.latex-project.org/lppl.txt
+%% 
+%% This work is "maintained" (as per LPPL maintenance status) by
+%%   Joseph Wright.
+%% 
+%% This work consists of the file  siunitx.dtx
+%%           and the derived files siunitx.pdf,
+%%                                 siunitx.sty and
+%%                                 siunitx.ins.
+%% 
+%%
+%% End of file `siunitx-abbreviations.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/si-USA.cfg b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-binary.cfg
index 2710d1fc42e..32707c3458b 100644
--- a/Master/texmf-dist/tex/latex/siunitx/config/si-USA.cfg
+++ b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-binary.cfg
@@ -1,10 +1,10 @@
 %%
-%% This is file `si-USA.cfg',
+%% This is file `siunitx-binary.cfg',
 %% generated with the docstrip utility.
 %%
 %% The original source files were:
 %%
-%% siunitx.dtx  (with options: `USA')
+%% siunitx.dtx  (with options: `config,binary')
 %% ---------------------------------------------------------------
 %% The siunitx package --- A comprehensive (SI) units package
 %% Maintained by Joseph Wright
@@ -13,16 +13,18 @@
 %% See http://www.latex-project.org/lppl.txt
 %% ---------------------------------------------------------------
 %% 
-\ProvidesFile{si-USA.cfg}
-  [2010/02/22 v1.4c siunitx: USA locale]
-\sisetup{
-  unitsep=thin,
-  expproduct=times,
-  valuesep=thin,
-  decimalsymbol=fullstop,
-  digitsep=thin,
-  sepfour=false,
-  tophrase={{ to }}}
+\ProvidesExplFile {siunitx-binary.cfg} {2010/05/23} {2.0}
+  {siunitx: Binary units}
+\DeclareBinaryPrefix \kibi { Ki } { 10 }
+\DeclareBinaryPrefix \mebi { Mi } { 20 }
+\DeclareBinaryPrefix \gibi { Gi } { 30 }
+\DeclareBinaryPrefix \tebi { Ti } { 40 }
+\DeclareBinaryPrefix \pebi { Pi } { 50 }
+\DeclareBinaryPrefix \exbi { Ei } { 60 }
+\DeclareBinaryPrefix \zebi { Zi } { 70 }
+\DeclareBinaryPrefix \yobi { Yi } { 80 }
+\DeclareSIUnit \bit  { bit }
+\DeclareSIUnit \byte { B }
 %% 
 %% Copyright (C) 2008-2010 by
 %%   Joseph Wright <joseph.wright@morningstar2.co.uk>
@@ -39,11 +41,8 @@
 %% 
 %% This work consists of the file  siunitx.dtx
 %%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
+%%                                 siunitx.sty and
+%%                                 siunitx.ins.
 %% 
 %%
-%% End of file `si-USA.cfg'.
+%% End of file `siunitx-binary.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/config/siunitx-version-1.cfg b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-version-1.cfg
new file mode 100644
index 00000000000..c7129987c98
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/siunitx/config/siunitx-version-1.cfg
@@ -0,0 +1,661 @@
+%%
+%% This is file `siunitx-version-1.cfg',
+%% generated with the docstrip utility.
+%%
+%% The original source files were:
+%%
+%% siunitx.dtx  (with options: `config,version-1')
+%% ---------------------------------------------------------------
+%% The siunitx package --- A comprehensive (SI) units package
+%% Maintained by Joseph Wright
+%% E-mail: joseph.wright@morningstar2.co.uk
+%% Released under the LaTeX Project Public License v1.3c or later
+%% See http://www.latex-project.org/lppl.txt
+%% ---------------------------------------------------------------
+%% 
+\ProvidesExplFile {siunitx-version-1.cfg} {2010/05/23} {2.0}
+  {siunitx: Version 1 settings}
+\keys_set:nn { siunitx } { load-configurations = abbreviations }
+\keys_define:nn { siunitx } {
+  addsign        .choice: ,
+  addsign /
+    false        .meta:n    = { explicit-sign           =             },
+  addsign /
+    true         .meta:n    = { explicit-sign           = +           },
+  addsign        .default:n = { true                                  },
+  allowlitunits  .meta:n    = { free-standing-units     = #1          },
+  allowlitunits  .default:n = { true                                  },
+  allowoptarg    .meta:n    = { unit-optional-argument  = #1          },
+  allowoptargs   .default:n = { true                                  },
+  allowzeroexp   .meta:n    = { retain-zero-exponent    = #1          },
+  allowzeroexp   .default:n = { true                                  },
+  angelsep       .choice: ,
+  angelsep /
+    cdot         .meta:n    =
+      { arc-separator         = { } \cdot { }                         },
+  angelsep /
+    comma        .meta:n    = { arc-separator           = { {,} }     },
+  angelsep /
+    fullstop     .meta:n    = { arc-separator           = { { . } }   },
+  angelsep /
+    med          .meta:n    = { arc-separator           = \:          },
+  angelsep /
+    medium       .meta:n    = { arc-separator           = \:          },
+  angelsep /
+    none         .meta:n    = { arc-separator           =             },
+  angelsep /
+    period       .meta:n    = { arc-separator           = { { . } }   },
+  angelsep /
+    space        .meta:n    = { arc-separator           = \text { ~ } },
+  angelsep /
+    stop         .meta:n    = { arc-separator           = { { . } }   },
+  angelsep /
+    thick        .meta:n    = { arc-separator           = \;          },
+  angelsep /
+    thin         .meta:n    = { arc-separator           = \,          },
+  angelsep /
+    tightcdot    .meta:n    =
+      { arc-separator           = \bgroup \cdot \egroup               },
+  angelsep /
+    tighttimes   .meta:n    =
+      { arc-separator           = \bgroup \times \egroup              },
+  angelsep /
+    times        .meta:n    = { arc-separator           = \times      },
+  angelsep /
+    unknown      .meta:n    = { arc-separator           = #1          },
+  astroang       .meta:n    =
+    { angle-symbol-over-decimal = #1                                  },
+  astroang       .default:n = { true                                  },
+  closeerr       .meta:n    = { close-bracket           = #1          },
+  closefrac      .meta:n    = { close-bracket           = #1          },
+  closerange     .meta:n    = { close-bracket           = #1          },
+  colorall       .code:n    = ,
+  colourall      .code:n    = ,
+  colorneg       .code:n    = ,
+  colourneg      .code:n    = ,
+  colorunits     .meta:n    = ,
+  colourunits    .meta:n    = ,
+  colorvalues    .meta:n    = ,
+  colourvalues   .meta:n    = ,
+  decimalsymbol  .choice: ,
+  decimalsymbol /
+    cdot         .meta:n    =
+      { output-decimal-marker   = { } \cdot { }                       },
+  decimalsymbol
+    fullstop     .meta:n    = { output-decimal-marker   = { { . } }   },
+  decimalsymbol /
+    period       .meta:n    = { output-decimal-marker   = { { . } }   },
+  decimalsymbol /
+    stop         .meta:n    = { output-decimal-marker   = { { . } }   },
+  decimalsymbol /
+    tightcdot    .code:n    =
+      { output-decimal-marker   = \bgroup \cdot \egroup               },
+  decimalsymbol /
+    unknown      .meta:n    = { output-decimal-marker   = #1          },
+  debug          .code:n    = ,
+  detectdisplay  .meta:n    = { detect-display-math     = #1          },
+  detectdisplay  .default:n = { true                                  },
+  digitsep       .choice: ,
+  digitsep /
+    cdot         .meta:n    =
+      { group-separator       = { } \cdot { }                         },
+  digitsep /
+    comma        .meta:n    = { group-separator         = { , }       },
+  digitsep /
+    fullstop     .meta:n    = { group-separator         = .           },
+  digitsep /
+    med          .meta:n    = { group-separator         = \:          },
+  digitsep /
+    medium       .meta:n    = { group-separator         = \:          },
+  digitsep /
+    none         .meta:n    = { group-separator         =             },
+  digitsep /
+    period       .meta:n    = { group-separator         = .           },
+  digitsep /
+    space        .meta:n    = { group-separator         = \text { ~ } },
+  digitsep /
+    stop         .meta:n    = { group-separator         = .           },
+  digitsep /
+    thick        .meta:n    = { group-separator         = \;          },
+  digitsep /
+    thin         .meta:n    = { group-separator         = \,          },
+  digitsep /
+    tightcdot    .meta:n    =
+      { group-separator         = \bgroup \cdot \egroup               },
+  digitsep /
+    tighttimes  .meta:n     =
+      { group-separator         = \bgroup \times \egroup              },
+  digitsep /
+    times        .meta:n    = { group-separator         = \times      },
+  digitsep /
+    unknown      .meta:n    = { group-separator         = #1          },
+  dp             .meta:n    =
+    {
+      round-mode      = places,
+      round-precision = #1,
+    },
+  emulate        .code:n    = ,
+  errspace       .choice: ,
+  errspace /
+    med          .meta:n    = { uncertainty-separator   = \:          },
+  errspace /
+    medium       .meta:n    = { uncertainty-separator   = \:          },
+  errspace /
+    none         .meta:n    = { uncertainty-separator   =             },
+  errspace /
+    space        .meta:n    = { uncertainty-separator   = \text { ~ } },
+  errspace /
+    thick        .meta:n    = { uncertainty-separator   = \;          },
+  errspace /
+    thin         .meta:n    = { uncertainty-separator   = \,          },
+  errspace /
+    unknown      .meta:n    = { uncertainty-separator   = #1          },
+  eVcorra        .code:n    = ,
+  eVcorrb        .code:n    = ,
+  expbase        .choice: ,
+  expbase /
+    ten          .meta:n    = { exponent-base           = 10          },
+  expbase /
+    two          .meta:n    = { exponent-base           = 2           },
+  expbase /
+    unknown      .meta:n    = { exponent-base           = #1          },
+  expproduct /
+    cdot         .meta:n    =
+      { exponent-product        = { } \cdot { }                       },
+  expproduct /
+    tightcdot    .meta:n    =
+      { exponent-product        = \bgroup \cdot \egroup                },
+  expproduct /
+    tighttimes   .meta:n    =
+      { exponent-product        = \bgroup \times \egroup             },
+  expproduct /
+    times        .meta:n    = { exponent-product        = \times     },
+  expproduct /
+    unknown      .meta:n    = { exponent-product        = #1         },
+  fixdp .choice:,
+  fixdp /
+    false        .meta:n    = { round-mode              = none        },
+  fixdp /
+    true         .meta:n    = { round-mode              = places      },
+  fixdp          .default:n = { true                                  },
+  fixsf          .choice: ,
+  fixsf /
+    false        .meta:n    = { round-mode              = none        },
+  fixsf /
+    true         .meta:n    = { round-mode              = figures     },
+  fixsf          .default:n = { true                                  },
+  fraction       .choice: ,
+  fraction /
+    frac         .meta:n    = { fraction-function       = \frac       },
+  fraction /
+    nice         .meta:n    = { fraction-function       = \frac       },
+  fraction /
+    sfrac        .meta:n    = { fraction-function       = \sfrac      },
+  fraction /
+    ugly         .meta:n    =
+      {
+        fraction-function       = \frac ,
+        per-mode                = symbol-or-fraction
+      },
+  inlinebold     .meta:n    = { detect-inline-weight    = #1          },
+  log            .code:n    = ,
+  load           .code:n    = ,
+  mathOmega      .meta:n    = { math-ohm                = #1          },
+  mathcelsius    .meta:n    = { math-celsius            = #1          },
+  mathdegree     .meta:n    = { math-degree             = #1          },
+  mathminute     .meta:n    = { math-arcminute          = #1          },
+  mathmu         .meta:n    = { math-micro              = #1          },
+  mathringA      .meta:n    = { math-angstrom           = #1          },
+  mathrm         .meta:x    =
+    { math-rm                 = \exp_not:c {#1}                       },
+  mathsOmega     .meta:n    = { math-ohm                = #1          },
+  mathscelsius   .meta:n    = { math-celsius    .       = #1          },
+  mathsdegree    .meta:n    = { math-degree     .       = #1          },
+  mathsecond     .meta:n    = { math-arcsecond          = #1          },
+  mathsf         .meta:x    =
+    { math-sf                 = \exp_not:c {#1}                       },
+  mathsminute    .meta:n    = { math-arcminute          = #1          },
+  mathsmu        .meta:n    = { math-micro              = #1          },
+  mathsringA     .meta:n    = { math-angstrom           = #1          },
+  mathsrm        .meta:x    =
+    { math-rm                 = \exp_not:c {#1}                       },
+  mathssecond    .meta:n    = { math-arcsecond          = #1          },
+  mathssf        .meta:x    =
+    { math-sf                 = \exp_not:c {#1}                       },
+  mathstt        .meta:x    =
+    { math-tt                 = \exp_not:c {#1}                       },
+  mathtt         .meta:x    =
+    { math-tt                 = \exp_not:c {#1}                       },
+  negcolor       .meta:n    = { negative-color          = #1          },
+  negcolour      .meta:n    = { negative-color          = #1          },
+  noload         .code:n    = ,
+  numaddn        .meta:n    = { input-symbols           = #1          },
+  numcloseerr    .meta:n    = { input-close-uncertainty = #1          },
+  numdecimal     .meta:n    = { input-decimal-markers   = #1          },
+  numdigits      .meta:n    = { input-digits            = #1          },
+  numdiv         .meta:n    = { input-quotient          = #1          },
+  numexp         .meta:n    = { input-exponent-markers  = #1          },
+  numgobble      .meta:n    = { input-ignore            = #1          },
+  numopenerr     .meta:n    = { input-open-uncertainty  = #1          },
+  numprod        .meta:n    = { input-product           = #1          },
+  numsign        .meta:n    = { input-signs             = #1          },
+  obeyall        .meta:n    = { detect-all              = #1          },
+  obeyall        .default:n = { true                                  },
+  obeybold       .meta:n    = { detect-weight           = #1          },
+  obeybold       .default:n = { true                                  },
+  obeyitalic     .meta:n    = { detect-italic           = #1          },
+  opbeyitalic    .default:n = { true                                  },
+  obeymode       .meta:n    = { detect-mode             = #1          },
+  obeymode       .default:n = { true                                  },
+  openerr        .meta:n    = { open-bracket            = #1          },
+  openfrac       .meta:n    = { open-bracket            = #1          },
+  openrange      .meta:n    = { open-bracket            = #1          },
+  padangle       .choice: ,
+  padangle /
+    all          .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+    both         .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+  padangle /
+    false        .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = false,
+        add-arc-second-zero = false
+      },
+  padangle /
+    large        .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = false
+      },
+  padangle /
+    none         .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = false,
+        add-arc-second-zero = false
+      },
+  padangle /
+    small         .meta:n    =
+      {
+        add-arc-degree-zero = false,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+    true         .meta:n    =
+      {
+        add-arc-degree-zero = true,
+        add-arc-minute-zero = true,
+        add-arc-second-zero = true
+      },
+  padnumber      .choice: ,
+  padnumber /
+    all          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  padnumber /
+    both          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  padnumber /
+    false         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = false
+      },
+  padnumber /
+    leading        .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = false
+      },
+  padnumber /
+    none         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = false
+      },
+  padnumber /
+    trailing         .meta:n    =
+      {
+        add-decimal-zero = false,
+        add-integer-zero = true
+      },
+  padnumber /
+    true          .meta:n    =
+      {
+        add-decimal-zero = true,
+        add-integer-zero = true
+      },
+  per           .choice: ,
+  per /
+    fraction     .meta:n    = { per-mode                = fraction    },
+  per /
+    reciprocal   .meta:n    = { per-mode                = reciprocal  },
+  per /
+    slash        .meta:n    = { per-mode                = symbol      },
+  prefixbase     .code:n    = ,
+  prefixproduct  .code:n    = ,
+  prefixsymbolic .meta:n    = { prefixes-as-symbols     = #1          },
+  prefixsymbolic .default:n = { true                                  },
+  prespace       .meta:n    = { space-before-unit       = #1          },
+  prespace       .default:n = { true                                  },
+  redefsymbols   .meta:n    = { redefine-symbols        = #1          },
+  redefsymbols   .default:n = { true                                  },
+  repeatunits    .choice: ,
+  repeatunits /
+    false        .meta:n    =
+      {
+        multi-part-numbers    = single,
+        product-units         = single,
+      },
+  repeatunits /
+    power        .meta:n    =
+      {
+        multi-part-numbers    = repeat,
+        product-units         = power,
+      },
+  repeatunits /
+    true        .meta:n       =
+      {
+        multi-part-numbers    = repeat,
+        product-units         = repeat,
+      },
+  repeatunits    .default:n = { true                                  },
+  retainplus     .meta:n    = { retain-explicit-plus    = #1          },
+  retainplus     .default:n = { true                                  },
+  seperr         .meta:n    = { separate-uncertainty    = #1          },
+  seperr         .default:n = { true                                  },
+  sepfour        .meta:n    = { group-four-digits       = true        },
+  sepfour        .default:n = { true                                  },
+  sf             .meta:n    =
+    {
+      round-mode      = figures,
+      round-precision = #1,
+    },
+  sign           .meta:n    = { explicit-sign           = #1          },
+  slash          .choice: ,
+  slash /
+    slash        .meta:n    = { per-symbol              = /           },
+  slash /
+    unknown      .meta:n    = { per symbol              = #1          },
+  stickyper      .meta:n    = { sticky-per              = #1          },
+  stickyper      .default:n = { true                                  },
+  strictarc      .code:n    = ,
+  tabalign       .meta:n    =
+    {
+      table-number-alignment  = #1,
+      table-text-alignment    = #1,
+      table-unit-alignment    = #1
+    },
+  tabalignexp    .code:n    = ,
+  tabautofit     .meta:n    = { table-auto-round        = #1          },
+  tabformat      .meta:n    = { table-format            = #1          },
+  tabnumalign    .meta:n    = { table-number-alignment  = #1          },
+  tabparseonly   .meta:n    = { table-parse-only        = #1          },
+  tabparseonly   .default:n = { true                                  },
+  tabtextalign   .meta:n    = { table-text-numbers      = #1          },
+  tabunitalign   .meta:n    = { table-unit-alignment    = #1          },
+  textOmega      .meta:n    = { text-ohm                = #1          },
+  textcelsius    .meta:n    = { text-celsius            = #1          },
+  textdegree     .meta:n    = { text-degree             = #1          },
+  textminute     .meta:n    = { text-arcminute          = #1          },
+  textmode       .choice: ,
+  textmode /
+    true         .meta:n    = { mode                    = text        },
+  textmode /
+    false        .meta:n    = { mode                    = math        },
+  textmode       .default:n = { true                                  },
+  textmu         .meta:n    = { text-micro              = #1          },
+  textringA      .meta:n    = { text-angstrom           = #1          },
+  textrm         .meta:x    =
+    { text-rm                 = \exp_not:c {#1}                       },
+  textsecond     .meta:n    = { text-arcsecond          = #1          },
+  textsf         .meta:x    =
+    { text-sf                 = \exp_not:c {#1}                       },
+  texttt         .meta:x    =
+    { text-tt                 = \exp_not:c {#1}                       },
+  tightpm        .meta:n    = { tight-spacing           = #1          },
+  tightpm        .default:n = { true                                  },
+  tophrase       .meta:n    = { range-phrase            = #1          },
+  trapambigerr   .choice: ,
+  trapambigerr
+    / false      .meta:n    = { multi-part-units        = single      },
+  trapambigerr
+    / true       .meta:n    = { multi-part-units        = brackets    },
+  trapambigerr   .default:n = { true                                  },
+  trapambigfrac  .meta:n    = { bracket-numbers         = #1          },
+  trapambigfrac  .default:n = { true                                  },
+  trapambigrange .choice: ,
+  trapambigrange
+    / false      .meta:n    = { range-units             = single      },
+  trapambigrange
+    / true       .meta:n    = { range-units             = brackets    },
+  trapambigrange .default:n = { true                                  },
+  unitcolor      .meta:n    = { unit-color              = #1          },
+  unitcolour     .meta:n    = { unit-color              = #1          },
+  unitmathrm     .meta:x    =
+    { unit-math-rm            = \exp_not:c {#1}                       },
+  unitmathsf     .meta:x    =
+    { unit-math-sf            = \exp_not:c {#1}                       },
+  unitmathsrm    .meta:x    =
+    { unit-math-rm            = \exp_not:c {#1}                       },
+  unitmathssf    .meta:x    =
+    { unit-math-sf            = \exp_not:c {#1}                       },
+  unitmathstt    .meta:x    =
+    { unit-math-tt            = \exp_not:c {#1}                       },
+  unitmathtt     .meta:x    =
+    { unit-math-tt            = \exp_not:c {#1}                       },
+  unitmode       .meta:n    = { unit-mode               = #1          },
+  unitsep        .choice: ,
+  unitsep /
+    cdot         .meta:n    =
+      { inter-unit-separator    = { } \cdot { }                       },
+  unitsep /
+    comma        .meta:n    = { inter-unit-separator    = { {,} }     },
+  unitsep /
+    fullstop     .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep /
+    med          .meta:n    = { inter-unit-separator    = \:          },
+  unitsep /
+    medium       .meta:n    = { inter-unit-separator    = \:          },
+  unitsep /
+    none         .meta:n    = { inter-unit-separator    =             },
+  unitsep /
+    period       .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep /
+    space        .meta:n    = { inter-unit-separator    = \text { ~ } },
+  unitsep /
+    stop         .meta:n    = { inter-unit-separator    = { { . } }   },
+  unitsep /
+    thick        .meta:n    = { inter-unit-separator    = \;          },
+  unitsep /
+    thin         .meta:n    = { inter-unit-separator    = \,          },
+  unitsep /
+    tightcdot    .meta:n    =
+      { inter-unit-separator    = \bgroup \cdot \egroup               },
+  unitsep /
+    tighttimes   .meta:n    =
+      { inter-unit-separator    = \bgroup \times \egroup              },
+  unitsep /
+    times        .meta:n   = { inter-unit-separator     = \times      },
+  unitsep /
+    unknown      .meta:n   = { inter-unit-separator     = #1          },
+  unitspace      .choice: ,
+  unitspace /
+    med          .meta:n   = { inter-unit-separator     = \:          },
+  unitspace /
+    medium       .meta:n   = { inter-unit-separator     = \:          },
+  unitspace /
+    none         .meta:n   = { inter-unit-separator     =             },
+  unitspace /
+    space        .meta:n   = { inter-unit-separator     = \text { ~ } },
+  unitspace /
+    thick        .meta:n   = { inter-unit-separator     = \;          },
+  unitspace /
+    thin         .meta:n   = { inter-unit-separator     = \,          },
+  unitspace /
+    unknown      .meta:n   = { inter-unit-separator     = #1          },
+  valuecolor     .meta:n   = { number-color             = #1          },
+  valuecolour    .meta:n   = { number-color             = #1          },
+  valuemathrm    .meta:x   =
+    { number-math-rm           = \exp_not:c {#1}                      },
+  valuemathsf    .meta:x   =
+    { number-math-sf           = \exp_not:c {#1}                      },
+  valuemathsrm   .meta:x   =
+    { number-math-rm           = \exp_not:c {#1}                      },
+  valuemathssf   .meta:x   =
+    { number-math-sf           = \exp_not:c {#1}                      },
+  valuemathstt   .meta:x   =
+    { number-math-tt           = \exp_not:c {#1}                      },
+  valuemathtt    .meta:x   =
+    { number-math-tt           = \exp_not:c {#1}                      },
+  valuemode      .meta:n   = { number-mode              = #1          },
+  valuesep        .choice: ,
+  valuesep /
+    cdot         .meta:n    =
+      { unit-value-separator    = { } \cdot { }                       },
+  valuesep /
+    comma        .meta:n    = { unit-value-separator    = { {,} }     },
+  valuesep /
+    fullstop     .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep /
+    med          .meta:n    = { unit-value-separator    = \:          },
+  valuesep /
+    medium       .meta:n    = { unit-value-separator    = \:          },
+  valuesep /
+    none         .meta:n    = { unit-value-separator    =             },
+  valuesep /
+    period       .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep /
+    space        .meta:n    = { unit-value-separator    = \text { ~ } },
+  valuesep /
+    stop         .meta:n    = { unit-value-separator    = { { . } }   },
+  valuesep /
+    thick        .meta:n    = { unit-value-separator    = \;          },
+  valuesep /
+    thin         .meta:n    = { unit-value-separator    = \,          },
+  valuesep /
+    tightcdot    .meta:n    =
+      { unit-value-separator    = \bgroup \cdot \egroup               },
+  valuesep /
+    tighttimes   .meta:n    =
+      { unit-value-separator    = \bgroup \times \egroup              },
+  valuesep /
+    times        .meta:n    = { unit-value-separator     = \times     },
+  valuesep /
+    unknown      .meta:n    = { unit-value-separator     = #1         },
+  xspace         .meta:n    = { use-xspace               = #1         },
+  xpace          .default:n = { true                                  }
+}
+\cs_set_eq:NN \newunit     \DeclareSIUnit
+\cs_set_eq:NN \renewunit   \DeclareSIUnit
+\cs_set_eq:NN \provideunit \DeclareSIUnit
+\NewDocumentCommand \newpower     { o m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+\NewDocumentCommand \renewpower   { o m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+\NewDocumentCommand \providepower { o m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrePower  #2 {#3} }
+    { \DeclareSIPostPower #2 {#3} }
+}
+\NewDocumentCommand \newprefix     { o m m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+\NewDocumentCommand \renewprefix   { o m m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+\NewDocumentCommand \provideprefix { o m m m } {
+  \IfNoValueTF {#1}
+    { \DeclareSIPrefix     #2 {#3} {#4} }
+    { \DeclareBinaryPrefix #2 {#3} {#4} }
+}
+\cs_set_eq:NN \newqualifier     \DeclareSIQualifier
+\cs_set_eq:NN \renewqualifier   \DeclareSIQualifier
+\cs_set_eq:NN \providequalifier \DeclareSIQualifier
+\DeclareSIPrePower \Square  { 2 }
+\DeclareSIPrePower \ssquare { 2 }
+\DeclareSIUnit \BAR   { \bar }
+\DeclareSIUnit \bbar  { \bar }
+\DeclareSIUnit \Day   { \day }
+\DeclareSIUnit \dday  { \day }
+\DeclareSIUnit \Gray  { \gray }
+\DeclareSIUnit \ggray { \gray }
+\DeclareSIUnit \atomicmass { \atomicmassunit }
+\DeclareSIUnit \arcmin     { \arcminute }
+\DeclareSIUnit \arcsec     { \arcsecond }
+\DeclareSIUnit \are      { a }
+\DeclareSIUnit \curie    { Ci }
+\DeclareSIUnit \gal      { Gal }
+\DeclareSIUnit \millibar { \milli \bar }
+\DeclareSIUnit \rad      { rad }
+\DeclareSIUnit \rem      { rem }
+\DeclareSIUnit \roentgen { R }
+\DeclareSIUnit \micA   { \micro \ampere }
+\DeclareSIUnit \micmol { \micro \mole   }
+\DeclareSIUnit \micl   { \micro \litre  }
+\DeclareSIUnit \micL   { \micro \liter  }
+\DeclareSIUnit \nanog  { \nano  \gram   }
+\DeclareSIUnit \micg   { \micro \gram   }
+\DeclareSIUnit \picm   { \pico  \metre  }
+\DeclareSIUnit \micm   { \micro \metre  }
+\DeclareSIUnit \Sec    { \second }
+\DeclareSIUnit \mics   { \micro \second }
+\DeclareSIUnit \cmc    { \centi \metre \cubed }
+\DeclareSIUnit \dmc    { \deci  \metre \cubed }
+\DeclareSIUnit \cms    { \centi \metre \squared }
+\DeclareSIUnit \parsec    { pc }
+\DeclareSIUnit \lightyear { ly }
+\DeclareSIUnit \gmol  { g  \text { - } mol }
+\DeclareSIUnit \kgmol { kg \text { - } mol }
+\DeclareSIUnit \lbmol { lb \text { - } mol }
+\DeclareSIUnit \molar { \mole \per \cubic \deci \metre }
+\DeclareSIUnit \Molar { \textsc { m } }
+\DeclareSIUnit \torr  { Torr }
+\DeclareSIUnit \gon    { gon }
+%% 
+%% Copyright (C) 2008-2010 by
+%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
+%% 
+%% It may be distributed and/or modified under the conditions of
+%% the LaTeX Project Public License (LPPL), either version 1.3c of
+%% this license or (at your option) any later version.  The latest
+%% version of this license is in the file:
+%% 
+%%    http://www.latex-project.org/lppl.txt
+%% 
+%% This work is "maintained" (as per LPPL maintenance status) by
+%%   Joseph Wright.
+%% 
+%% This work consists of the file  siunitx.dtx
+%%           and the derived files siunitx.pdf,
+%%                                 siunitx.sty and
+%%                                 siunitx.ins.
+%% 
+%%
+%% End of file `siunitx-version-1.cfg'.
diff --git a/Master/texmf-dist/tex/latex/siunitx/siunitx.sty b/Master/texmf-dist/tex/latex/siunitx/siunitx.sty
index 90b94d7132f..a407b5d22b6 100644
--- a/Master/texmf-dist/tex/latex/siunitx/siunitx.sty
+++ b/Master/texmf-dist/tex/latex/siunitx/siunitx.sty
@@ -13,3961 +13,5743 @@
 %% See http://www.latex-project.org/lppl.txt
 %% ---------------------------------------------------------------
 %% 
-\NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{siunitx}
-  [2010/02/22 v1.4c A comprehensive (SI) units package]
-\begingroup
-  \@ifundefined{eTeXversion}
-    {\PackageError{siunitx}
-       {Not running under e-TeX}
-       {This package requires e-TeX. Try compiling the document
-        with\MessageBreak `elatex' instead of `latex'. When
-        using pdfTeX, try `pdfelatex'\MessageBreak instead of
-        `pdflatex'}%
-     \endgroup\endinput}
-    {\endgroup}
-\edef\si@catcodes{%
-  \catcode\string`\string ` \the\catcode\string`\`\relax
-  \catcode\string`\string = \the\catcode\string`\=\relax
-  \catcode\string`\string ^ \the\catcode\string`\^\relax
-  \catcode\string`\string _ \the\catcode\string`\_\relax
-  \catcode\string`\string ~ \the\catcode\string`\~\relax
-  \catcode\string`\string : \the\catcode\string`\:\relax
-  \catcode\string`\string - \the\catcode\string`\-\relax
-  \catcode\string`\string + \the\catcode\string`\+\relax
-  \catcode\string`\string ; \the\catcode\string`\;\relax
-  \catcode\string`\string , \the\catcode\string`\,\relax
-  \catcode\string`\string . \the\catcode\string`\.\relax}
-\catcode\string`\` 12\relax
-\catcode`\= 12\relax
-\catcode`\^ 7\relax
-\catcode`\_ 8\relax
-\catcode`\~ \active\relax
-\@makeother{\:}
-\@makeother{\-}
-\@makeother{\+}
-\@makeother{\;}
-\@makeother{\,}
-\@makeother{\.}
-\RequirePackage{xkeyval}[2005/05/07]
-\RequirePackage{amstext,array,xspace}
-\newcommand*{\si@tempa}{}
-\newcommand*{\si@tempb}{}
-\newcommand*{\si@tempc}{}
-\newif\ifsi@switch
-\newbox\si@tempboxa
-\newbox\si@tempboxb
-\newbox\si@tempboxc
-\newbox\si@tempboxd
-\newtoks{\si@temptoks}
-\newcommand*{\si@blockpkgs}{SIunits,sistyle,siunits,SIstyle,%
-  unitsdef,fancyunits}
-\newcommand*{\si@checkpkgs}{units,hepunits,fancynum}
-\newcommand*{\si@packagecheck}{%
-  \begingroup
-  \@for\si@tempa:=\si@blockpkgs\do{
-    \@ifpackageloaded{\si@tempa}
-      {\PackageError{siunitx}
-         {Package `\si@tempa' incompatible}
-         {The \si@tempa\space package and siunitx are
-          incompatible.\MessageBreak Use the
-          `emulate=\si@tempa' package option when loading
-          siunitx}}
-      {}}
-  \@for\si@tempa:=\si@checkpkgs\do{%
-    \@ifpackageloaded{\si@tempa}
-      {\PackageWarning{siunitx}
-         {Consider loading the siunitx package
-          with\MessageBreak option `emulate=\si@tempa', rather
-          than\MessageBreak loading both \si@tempa\space and
-          siunitx}}
-      {}}
-  \endgroup}
-\si@packagecheck
-\AtBeginDocument{\si@packagecheck}
-\newcommand*{\si@ifdefinable}[1]{%
-  \expandafter\expandafter\expandafter\@ifundefined%
-    \expandafter\expandafter\expandafter%
-      {\expandafter\@gobble\string#1}}
-\newcommand*{\si@addtolist}[2]{%
-  \ifx\@empty#1\@empty
-    \edef#1{#2}%
-  \else
-    \edef#1{#1,#2}%
-  \fi}
-\newcommand*{\si@addtocsname}[2]{%
-  \@ifundefined{#1}
-    {\expandafter\gdef\csname #1\endcsname{#2}}
-    {\si@temptoks\expandafter\expandafter\expandafter{%
-       \csname #1\endcsname#2}%
-     \expandafter\xdef\csname #1\endcsname{\the\si@temptoks}}}
-\begingroup
-  \catcode`\Q=3
-  \long\gdef\si@ifmtarg#1{%
-    \si@xifmtarg#1QQ\@secondoftwo\@firstoftwo\@nil}
-  \long\gdef\si@xifmtarg#1#2Q#3#4#5\@nil{#4}
-  \long\gdef\si@ifnotmtarg#1{%
-    \si@xifmtarg#1QQ\@firstofone\@gobble\@nil}
-\endgroup
-\@ifpackageloaded{etoolbox}
-  {\let\si@newrobustcmd\newrobustcmd}
-  {\protected\def\si@newrobustcmd{%
-     \@ifstar
-       {\let\l@ngrel@x\protected\si@newcommand}
-       {\def\l@ngrel@x{\protected\long}\si@newcommand}}
-   \newcommand*{\si@newcommand}[1]{\@testopt{\si@newcmd#1}0}
-   \def\si@newcmd#1[#2]{%
-     \@ifnextchar[%]
-       {\si@xargdef#1[#2]}
-       {\@argdef#1[#2]}}
-   \long\def\si@xargdef#1[#2][#3]#4{%
-     \@ifdefinable#1{%
-       \expandafter\protected
-       \expandafter\def
-       \expandafter#1%
-       \expandafter{%
-         \expandafter\@testopt
-         \csname\string#1\endcsname{#3}}%
-       \expandafter\@yargdef
-       \csname\string#1\endcsname\tw@{#2}{#4}}}}
-\newif\ifsi@debug
-\newif\ifsi@logmin
-\newif\ifsi@lognone
-\newcommand*{\si@log@err}[2]{%
-  \ifsi@lognone\else
-    \ifsi@logmin
-      \PackageWarning{siunitx}{#1}%
-    \else
-      \PackageError{siunitx}{#1}{#2}%
-    \fi
-  \fi}
-\newcommand*{\si@log@warn}[1]{%
-  \ifsi@lognone\else
-    \ifsi@logmin\else
-      \PackageWarning{siunitx}{#1}%
-    \fi
-  \fi}
-\newcommand*{\si@log@inf}[1]{%
-  \ifsi@lognone\else
-    \ifsi@logmin\else
-      \PackageInfo{siunitx}{#1}%
-    \fi
-  \fi}
-\newcommand*{\si@log@debug}[1]{%
-  \ifsi@lognone\else
-    \ifsi@debug
-      \PackageInfo{siunitx}{#1}%
-    \fi
-  \fi}
-\newcommand*{\si@str@ifchrstr}[2]{%
-  \begingroup
-    \si@switchfalse
-    \renewcommand*{\si@tempa}{#1}%
-    \protected@edef\si@tempb{#2}%
-    \expandafter\si@str@chrstr\si@tempb\@empty\@empty\@empty
-    \ifsi@switch
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@str@chrstr#1#2\@empty{%
-  \renewcommand*{\si@tempc}{#1}%
-  \ifx\si@tempa\si@tempc
-    \expandafter\si@switchtrue
-  \else
-    \ifx\@empty#2\@empty\else
-      \si@str@chrstr#2\@empty\@empty
-    \fi
-  \fi}
-\newcommand*{\si@str@ifonlychrs}[2]{%
-  \begingroup
-    \si@switchtrue
-    \protected@edef\si@tempa{#1}%
-    \renewcommand*{\si@tempb}{#2}%
-    \expandafter\si@str@onlychrs\si@tempa\@empty\@empty\@empty
-    \ifsi@switch
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@str@onlychrs#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@tempb}
-    {}{\si@switchfalse}%
-  \ifx\@empty#2\@empty\else
-    \si@str@onlychrs#2\@empty\@empty
-  \fi}
-\newcommand*{\sisetup}{\setkeys[si]{key}}
-\newcommand*{\si@opt@key}[2]{%
-  \define@key[si]{key}{#1}
-  {#2\si@log@debug{Option #1 set to ##1}}}
-\newcommand*{\si@opt@cmdkey}[3][]{%
-  \define@cmdkey[si]{key}[si@]{#2}[#1]{#3}}
-\newcommand*{\si@opt@cmdkeys}[2][]{%
-  \define@cmdkeys[si]{key}[si@]{#2}[#1]}
-\newcommand*{\si@opt@boolkey}[2][]{%
-  \define@boolkey[si]{key}[si@]{#2}[true]
-  {#1\si@log@debug{Option #2 set to ##1}}}
-\newcommand*{\si@opt@choicekey}[4][]{%
-  \define@choicekey*+[si]{key}{#2}[\si@tempa]{#3}[#1]
-    {#4\si@log@debug{Option #2 set to ##1}}
-    {\si@log@warn{Unknown value `##1' for option #2}}}
-\newcommand*{\si@opt@xchoicekey}[3]{%
-  \define@choicekey*+[si]{key}{#1}[\si@tempa]{#2}[#1]
-    {\si@log@debug{Option #1 set to ##1}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-      \csname si@#1\endcsname}{\@nameuse{si@fix@##1}}}
-    {\si@log@debug{Option #1 set to ##1}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-      \csname si@#1\endcsname}{##1}}
-  \expandafter\newcommand\expandafter*\expandafter{%
-    \csname si@#1\endcsname}%
-    {\@nameuse{si@fix@#3}}}
-\newcommand*{\si@opt@compatkey}[2]{%
-  \define@boolkey[si]{key}[si@old@]{#2}[true]
-  {\si@log@debug{Emulating #1 package option\MessageBreak #2}%
-   \sisetup{emulate=#1}%
-   \si@log@debug{Option #2 set to ##1}}
-   \AtEndOfPackage{\si@opt@disablekey{#2}
-     {Compatibility option #2 only\MessageBreak
-        available when loading siunitx package}}}
-\newcommand*{\si@opt@disablekey}[2]{%
-  \key@ifundefined[si]{key}{#1}
-    {}
-    {\si@log@debug{Disabling key #1}%
-     \si@opt@key{#1}{\si@log@warn{#2}}}}
-\si@opt@choicekey[normal]{log}{debug,verbose,normal,errors,none}
-  {\si@debugfalse
-   \si@logminfalse
-   \si@lognonefalse
-   \renewcommand*{\si@tempb}{none}%
-   \ifx\si@tempa\si@tempb
-     \si@lognonetrue
-   \fi
-   \renewcommand*{\si@tempb}{minimal}%
-   \ifx\si@tempa\si@tempb
-     \si@logmintrue
-   \fi
-   \renewcommand*{\si@tempb}{debug}%
-   \ifx\si@tempa\si@tempb
-     \si@debugtrue
-   \fi
-   \renewcommand*{\si@tempb}{verbose}%
-   \ifx\si@tempa\si@tempb
-     \si@debugtrue
-   \fi}
-\si@opt@boolkey{debug}
-\si@opt@boolkey[%
-  \ifsi@strict
-    \sisetup{
-      obeymode=false,
-      obeybold=false,
-      obeyitalic=false,
-      mode=maths,
-      repeatunits=true,
-      trapambigerr=true,
-      trapambigfrac=true,
-      trapambigrange=true}
-    \@for\si@tempa:=obeyall,obeymode,obeyitalic,mode,unitmode,%
-      valuemode,textmode,obeybold,repeatunits,trapambigerr,%
-      trapambigfrac,trapambigrange\do{%
-      \begingroup
-        \edef\si@tempb{\endgroup
-          \noexpand\si@opt@disablekey{\si@tempa}
-          {Option `\si@tempa' forbidden in strict mode}}%
-      \si@tempb}
-  \fi]{strict}
-\AtEndOfPackage{
-  \si@opt@disablekey{strict}
-    {Option `strict' only available when\MessageBreak
-     loading package}}
-\newcommand*{\si@emulate}{}
-\si@opt@key{emulate}{\si@addtolist{\si@emulate}{#1}}
-\AtEndOfPackage{
-  \si@opt@disablekey{emulate}
-    {Option `emulate' only available when\MessageBreak
-     loading package}}
-\si@opt@xchoicekey{unitsep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-    times,tighttimes,cdot,tightcdot}{thin}
-\si@opt@xchoicekey{unitspace}{space,thin,med,medium,thick,
-  none}{thin}
-\si@opt@xchoicekey{errspace}{space,thin,med,medium,thick,
-  none}{none}
-\si@opt@xchoicekey{valuesep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
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-\si@opt@xchoicekey{digitsep}
-  {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-    times,tighttimes,cdot,tightcdot}{thin}
-\si@opt@xchoicekey{decimalsymbol}{comma,stop,fullstop,period,
-  cdot,tightcdot}{fullstop}
-\si@opt@xchoicekey{anglesep}
-    {space,thin,med,medium,thick,none,comma,stop,fullstop,period,
-      times,tighttimes,cdot,tightcdot}{none}
-\si@opt@boolkey{obeymode}
-\newif\ifsi@numtextmode
-\newif\ifsi@unittextmode
-\si@opt@choicekey[true]{textmode}{true,false}
-  {\si@numtextmodefalse
-   \si@unittextmodefalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-     \si@unittextmodetrue
-   \fi}
-\si@opt@choicekey{mode}{math,maths,text}
-  {\si@numtextmodefalse
-   \si@unittextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-     \si@unittextmodetrue
-   \fi}
-\si@opt@choicekey{valuemode}{math,maths,text}
-  {\si@numtextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@numtextmodetrue
-   \fi}
-\si@opt@choicekey{unitmode}{math,maths,text}
-  {\si@unittextmodefalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@unittextmodetrue
-   \fi}
-\si@opt@boolkey{obeyfamily}
-\si@opt@boolkey{obeybold}
-\newif\ifsi@inlinebtext
-\si@opt@choicekey{inlinebold}{text,maths,math}
-  {\si@inlinebtextfalse
-   \renewcommand*{\si@tempb}{text}%
-   \ifx\si@tempa\si@tempb
-     \si@inlinebtexttrue
-   \fi}
-\si@opt@boolkey{obeyitalic}
-\si@opt@boolkey{detectdisplay}
-\si@opt@choicekey[true]{obeyall}{true,false}
-  {\si@obeyboldfalse
-   \si@obeyitalicfalse
-   \si@obeymodefalse
-   \si@obeyfamilyfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
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-     \si@obeymodetrue
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-\si@opt@cmdkeys{valuemathsrm,valuemathssf,valuemathstt}
-\si@opt@cmdkeys{unitmathsrm,unitmathssf,unitmathstt}
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-\si@opt@key{valuemathsf}{\sisetup{valuemathssf=#1}}
-\si@opt@key{valuemathtt}{\sisetup{valuemathstt=#1}}
-\si@opt@key{unitmathrm}{\sisetup{unitmathsrm=#1}}
-\si@opt@key{unitmathsf}{\sisetup{unitmathssf=#1}}
-\si@opt@key{unitmathtt}{\sisetup{unitmathstt=#1}}
-\si@opt@key{mathsrm}{\sisetup{valuemathsrm=#1,unitmathsrm=#1}}
-\si@opt@key{mathssf}{\sisetup{valuemathssf=#1,unitmathssf=#1}}
-\si@opt@key{mathstt}{\sisetup{valuemathstt=#1,unitmathstt=#1}}
-\si@opt@key{mathrm}{\sisetup{valuemathsrm=#1,unitmathsrm=#1}}
-\si@opt@key{mathsf}{\sisetup{valuemathssf=#1,unitmathssf=#1}}
-\si@opt@key{mathtt}{\sisetup{valuemathstt=#1,unitmathstt=#1}}
-\si@opt@cmdkeys{valuetextrm,valuetextsf,valuetexttt}
-\si@opt@cmdkeys{unittextrm,unittextsf,unittexttt}
-\si@opt@key{textrm}{\sisetup{unittextrm=#1,valuetextrm=#1}}
-\si@opt@key{textsf}{\sisetup{unittextsf=#1,valuetextsf=#1}}
-\si@opt@key{texttt}{\sisetup{unittexttt=#1,valuetexttt=#1}}
-\si@opt@cmdkeys{numdigits,numdecimal,numexp,numgobble,numsign,%
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-\newcommand*{\si@numextra}{%
-  \si@numopenerr\si@numcloseerr\si@numaddn}
-\newcommand*{\si@numvalid}{\si@numgobble\si@numexp\si@numsign
-  \si@numdecimal\si@numdigits\si@numextra\si@numprod\si@numdiv}
-\si@opt@boolkey{seperr}
-\si@opt@boolkey{trapambigerr}
-\si@opt@cmdkeys{openerr,closeerr}
-\si@opt@boolkey{sepfour}
-\si@opt@boolkey{retainplus}
-\si@opt@xchoicekey{expproduct}{times,tighttimes,
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-\si@opt@xchoicekey{prefixproduct}{times,tighttimes,cdot,
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-\si@opt@boolkey{prefixsymbolic}
-\newif\ifsi@num@padlead
-\newif\ifsi@num@padtrail
-\si@opt@choicekey[all]{padnumber}
-  {leading,lead,trailing,trail,all,both,true,none,false}
-  {\si@num@padleadfalse
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-   \renewcommand*{\si@tempb}{leading}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-   \fi
-   \renewcommand*{\si@tempb}{lead}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-   \fi
-   \renewcommand*{\si@tempb}{trailing}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{trail}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@num@padleadtrue
-     \si@num@padtrailtrue
-   \fi}
-\newif\ifsi@num@signmant
-\newif\ifsi@num@signexp
-\si@opt@xchoicekey{sign}{plus,minus,pm,mp}{plus}
-\si@opt@choicekey[all]{addsign}
-  {mantissa,exponent,mant,exp,all,both,true,none,false}
-  {\si@num@signmantfalse
-   \si@num@signexpfalse
-   \renewcommand*{\si@tempb}{mantissa}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-   \fi
-   \renewcommand*{\si@tempb}{mant}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-   \fi
-   \renewcommand*{\si@tempb}{exponent}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{exp}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@num@signmanttrue
-     \si@num@signexptrue
-   \fi}
-\si@opt@boolkey{tightpm}
-\newcommand*{\si@pm}{%
-  \ifsi@tightpm
-    \si@fix@tightpm
-  \else
-    \si@fix@pm
-  \fi}
-\newif\ifsi@ang@padsmall
-\newif\ifsi@ang@padlarge
-\si@opt@choicekey[all]{padangle}
-  {small,large,all,both,true,none,false}
-  {\si@ang@padsmallfalse
-   \si@ang@padlargefalse
-   \renewcommand*{\si@tempb}{small}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-   \fi
-   \renewcommand*{\si@tempb}{large}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{all}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi
-   \renewcommand*{\si@tempb}{both}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@padsmalltrue
-     \si@ang@padlargetrue
-   \fi}
-\newif\ifsi@ang@toarc
-\newif\ifsi@ang@todec
-\si@opt@choicekey[all]{angformat}
-  {dec,decimal,arc,dms,unchanged,none}
-  {\si@ang@toarcfalse
-   \si@ang@todecfalse
-   \renewcommand*{\si@tempb}{dec}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@todectrue
-   \fi
-   \renewcommand*{\si@tempb}{decimal}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@todectrue
-   \fi
-   \renewcommand*{\si@tempb}{arc}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@toarctrue
-   \fi
-   \renewcommand*{\si@tempb}{dms}%
-   \ifx\si@tempa\si@tempb
-     \si@ang@toarctrue
-   \fi}
-\si@opt@boolkey{astroang}
-\si@opt@boolkey{strictarc}
-\newif\ifsi@tab@fixed
-\si@opt@boolkey{tabparseonly}
-\si@opt@choicekey{tabnumalign}
-  {centredecimal,centerdecimal,right,left,centre,center}
-  {\si@tab@fixedtrue
-   \def\si@tab@rfill@S{0.5}%
-   \def\si@tab@lfill@S{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@S{0}%
-     \def\si@tab@lfill@S{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@S{1}%
-     \def\si@tab@lfill@S{0}%
-   \fi
-   \renewcommand*{\si@tempb}{centredecimal}%
-   \ifx\si@tempa\si@tempb
-     \expandafter\si@tab@fixedfalse
-   \fi
-   \renewcommand*{\si@tempb}{centerdecimal}%
-   \ifx\si@tempa\si@tempb
-     \expandafter\si@tab@fixedfalse
-   \fi}
-\si@opt@key{tabalign}{\sisetup{tabnumalign=#1,tabtextalign=#1,
-  tabunitalign=#1}}
-\si@opt@boolkey{tabalignexp}
-\si@opt@boolkey[%
-  \si@tabalignexpfalse
-  \ifsi@tabexpalign
-    \expandafter\si@tabalignexptrue
-  \fi
-  ]{tabexpalign}
-\newcount\si@tab@mantprecnt
-\newcount\si@tab@mantpostcnt
-\newcount\si@tab@expprecnt
-\newcount\si@tab@exppostcnt
-\newif\ifsi@tab@mantsign
-\newif\ifsi@tab@expsign
-\si@opt@cmdkey{tabformat}
-  {\si@num@fixpm
-   \renewcommand*{\si@num@arg}{tabformat data}%
-   \renewcommand*{\si@num@exp}{}%
-   \renewcommand*{\si@num@mant}{}%
-   \si@tab@mantsignfalse
-   \si@tab@expsignfalse
-   \si@switchfalse
-   \si@num@sepmantexp{#1}%
-   \si@num@sepsign{mant}%
-   \ifx\@empty\si@num@mantsign\@empty
-     \ifsi@num@delplus
-       \expandafter\expandafter\expandafter\si@tab@mantsigntrue
-     \fi
-   \else
-     \expandafter\si@tab@mantsigntrue
-   \fi
-   \si@num@sepsign{exp}%
-   \ifx\@empty\si@num@expsign\@empty
-     \ifsi@num@delplus
-       \expandafter\expandafter\expandafter\si@tab@expsigntrue
-     \fi
-   \else
-     \expandafter\si@tab@expsigntrue
-   \fi
-   \si@opt@proctform{mant}%
-   \si@opt@proctform{exp}%
-   \ifnum\si@tab@mantpostcnt=\z@\relax
-     \ifnum\si@tab@mantprecnt=\z@\relax
-       \si@log@err{Empty mantissa argument for tabformat}
-         {The argument `#1' contains no valid entry for
-          a mantissa\MessageBreak It should be of the
-          form `m.n', where  m and n are integers}%
-     \fi
-   \fi
-   \ifsi@tab@fixed\else
-     \sisetup{tabnumalign=centre}%
-   \fi
-   \let\pm\si@num@pm
-   \let\mp\si@num@mp}
-\newcommand*{\si@opt@proctform}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \expandafter\si@ifnotmtarg\expandafter{%
-    \csname si@num@#1\endcsname}
-     {\expandafter\expandafter\expandafter\si@num@digits
-        \csname si@num@#1\endcsname\@empty\@empty}%
-   \csname si@tab@#1precnt\endcsname\z@\relax
-   \csname si@tab@#1postcnt\endcsname\z@\relax
-   \ifx\@empty\si@num@predec\@empty\else
-     \csname si@tab@#1precnt\endcsname\si@num@predec\relax
-   \fi
-   \ifx\@empty\si@num@postdec\@empty\else
-     \csname si@tab@#1postcnt\endcsname\si@num@postdec\relax
-   \fi}
-\si@opt@choicekey{tabtextalign}{left,right,centre,center}
-  {\def\si@tab@rfill@t{0.5}%
-   \def\si@tab@lfill@t{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@t{0}%
-     \def\si@tab@lfill@t{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@t{1}%
-     \def\si@tab@lfill@t{0}%
-   \fi}
-\si@opt@choicekey{tabunitalign}{left,right,centre,center}
-  {\def\si@tab@rfill@s{0.5}%
-   \def\si@tab@lfill@s{0.5}%
-   \renewcommand*{\si@tempb}{right}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@s{0}%
-     \def\si@tab@lfill@s{1}%
-   \fi
-   \renewcommand*{\si@tempb}{left}%
-   \ifx\si@tempa\si@tempb
-     \def\si@tab@rfill@s{1}%
-     \def\si@tab@lfill@s{0}%
-   \fi}
-\si@opt@boolkey[%
-  \ifsi@fixdp
-    \expandafter\si@fixsffalse
-  \fi]{fixdp}
-\newcount\si@num@dp
-\si@opt@key{dp}{%
-  \si@str@ifonlychrs{#1}{0123456789}
-    {\si@num@dp#1\relax
-     \si@fixdptrue
-     \si@fixsffalse}
-    {\si@log@err{Invalid input for dp option}
-      {The dp option must be given a positive integer}}}
-\si@opt@boolkey[%
-  \ifsi@fixsf
-    \expandafter\si@fixdpfalse
-  \fi]{fixsf}
-\newcount\si@num@sf
-\si@opt@key{sf}{%
-  \si@str@ifonlychrs{#1}{0123456789}
-    {\si@num@sf#1\relax
-     \ifnum\si@num@sf=\z@\relax
-       \si@log@warn{Setting sf=0 disables function}%
-       \si@fixsffalse
-     \else
-       \si@fixsftrue
-       \si@fixdpfalse
-     \fi}
-    {\si@log@err{Invalid input for sf option}
-      {The sf option must be given a positive integer}}}
-\si@opt@boolkey{tabautofit}
-\si@opt@boolkey{xspace}
-\si@opt@boolkey
-  [\si@unt@numfalse
-   \ifsi@prespace
-     \si@unt@numtrue
-  \fi]
-  {prespace}
-\si@opt@boolkey{allowoptarg}
-\si@opt@boolkey{allowlitunits}
-\newif\ifsi@slash
-\newif\ifsi@frac
-\si@opt@boolkey{stickyper}
-\si@opt@choicekey[reciprocal]{per}
-  {reciprocal,rp,power,slash,frac,fraction}
-  {\si@slashfalse
-   \si@fracfalse
-   \let\si@frac\si@frc@frac
-   \renewcommand*{\si@tempb}{slash}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-     \si@slashtrue
-     \let\si@frac\si@frc@slash
-   \fi
-   \renewcommand*{\si@tempb}{frac}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-   \fi
-   \renewcommand*{\si@tempb}{fraction}%
-   \ifx\si@tempa\si@tempb
-     \si@fractrue
-   \fi}
-\si@opt@xchoicekey{slash}{slash}{slash}
-\newif\ifsi@repeatunits
-\newif\ifsi@addunitpower
-\si@opt@choicekey[true]{repeatunits}{true,false,power}
-  {\si@repeatunitsfalse
-   \si@addunitpowerfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@repeatunitstrue
-   \fi
-   \renewcommand*{\si@tempb}{power}%
-   \ifx\si@tempa\si@tempb
-     \si@addunitpowertrue
-   \fi}
-\si@opt@boolkey{trapambigfrac}
-\si@opt@cmdkeys{closefrac,openfrac}
-\si@opt@choicekey[frac]{fraction}
-  {frac,nicefrac,nice,sfrac,xfrac,uglyfrac,ugly}
-  {\let\si@frac\si@frc@frac
-   \renewcommand*{\si@tempb}{nicefrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@nice
-   \fi
-   \renewcommand*{\si@tempb}{uglyfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@ugly
-   \fi
-   \renewcommand*{\si@tempb}{nice}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@nice
-   \fi
-   \renewcommand*{\si@tempb}{sfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@sfrac
-   \fi
-   \renewcommand*{\si@tempb}{xfrac}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@sfrac
-   \fi
-   \renewcommand*{\si@tempb}{ugly}%
-   \ifx\si@tempa\si@tempb
-     \let\si@frac\si@frc@ugly
-   \fi}
-\si@opt@cmdkeys{load,noload}
-\si@opt@key{alsoload}{\si@addtolist{\si@load}{#1}}
-\AtEndOfPackage{
-  \si@opt@disablekey{load}
-    {Configuration files can only be used\MessageBreak
-     when loading package}
-  \si@opt@disablekey{noload}
-    {Configuration files can only be used\MessageBreak
-     when loading package}}
-\AtEndOfPackage{
-  \si@opt@key{alsoload}{%
-    \@for\si@tempa:=#1\do{\si@loadfile{\si@tempa}}}}
-\si@opt@boolkey{colourunits}
-\si@opt@boolkey{colourvalues}
-\si@opt@choicekey[true]{colorunits}
-  {true,false}
-  {\si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-   \fi}
-\si@opt@choicekey[true]{colorvalues}
-  {true,false}
-  {\si@colourvaluesfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourvaluestrue
-   \fi}
-\si@opt@choicekey[true]{colorall}
-  {true,false}
-  {\si@colourvaluesfalse
-   \si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-     \si@colourvaluestrue
-   \fi}
-\si@opt@choicekey[true]{colourall}
-  {true,false}
-  {\si@colourvaluesfalse
-   \si@colourunitsfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colourunitstrue
-     \si@colourvaluestrue
-   \fi}
-\si@opt@cmdkeys{unitcolour,valuecolour}
-\si@opt@key{unitcolor}{\sisetup{unitcolour=#1}}
-\si@opt@key{valuecolor}{\sisetup{valuecolour=#1}}
-\si@opt@key{colour}{\sisetup{unitcolour=#1,valuecolour=#1}}
-\si@opt@key{color}{\sisetup{unitcolour=#1,valuecolour=#1}}
-\si@opt@boolkey{colourneg}
-\si@opt@choicekey[true]{colorneg}
-  {true,false}
-  {\si@colournegfalse
-   \renewcommand*{\si@tempb}{true}%
-   \ifx\si@tempa\si@tempb
-     \si@colournegtrue
-   \fi}
-\si@opt@cmdkeys{negcolour}
-\si@opt@key{negcolor}{\sisetup{negcolour=#1}}
-\si@opt@cmdkeys{textOmega,mathsOmega}
-\si@opt@key{mathOmega}{\sisetup{mathsOmega=#1}}
-\newcommand*{\si@mathsOmega}{\text{\ensuremath{\si@upOmega}}}
-\newcommand*{\si@textOmega}{\ensuremath{\si@upOmega}}
-\newcommand*\si@upOmega{}
-\AtBeginDocument{
-  \ifdefined\upOmega
-    \let\si@upOmega\upOmega
-  \else
-    \let\si@upOmega\Omega
-  \fi
-}
-\si@opt@cmdkeys{textmu,mathsmu}
-\si@opt@key{mathmu}{\sisetup{mathsmu=#1}}
-\DeclareFontEncoding{TS1}{}{}
-\DeclareFontSubstitution{TS1}{cmr}{m}{n}
-\DeclareTextSymbol{\si@textmu}{TS1}{181}
-\DeclareTextSymbolDefault{\si@textmu}{TS1}
-\def\si@mathsmu{\text{\si@textmu}}
-\si@opt@cmdkeys{textdegree,mathsdegree,textminute,mathsminute,
-  textsecond,mathssecond}
-\si@opt@key{mathdegree}{\sisetup{mathsdegree=#1}}
-\si@opt@key{mathminute}{\sisetup{mathsminute=#1}}
-\si@opt@key{mathsecond}{\sisetup{mathssecond=#1}}
-\newcommand*{\si@textdegree}{\ensuremath{{}^{\circ}}}
-\newcommand*{\si@mathsdegree}{{}^{\circ}}
-\newcommand*{\si@textminute}{\ensuremath{{}^{\prime}}}
-\newcommand*{\si@mathsminute}{{}^{\prime}}
-\newcommand*{\si@textsecond}{\ensuremath{{}^{\prime\prime}}}
-\newcommand*{\si@mathssecond}{{}^{\prime\prime}}
-\si@opt@cmdkeys{textcelsius,mathscelsius}
-\si@opt@key{mathcelsius}{\sisetup{mathscelsius=#1}}
-\newcommand*{\si@textcelsius}{%
-  \si@textdegree\kern-\scriptspace C}
-\newcommand*{\si@mathscelsius}{%
-  \si@mathsdegree\kern-\scriptspace C}
-\si@opt@cmdkeys{textringA,mathsringA}
-\si@opt@key{mathringA}{\sisetup{mathsringA=#1}}
-\newcommand*{\si@textringA}{\AA}
-\newcommand*{\si@mathsringA}{\text{\AA}}
-\si@opt@boolkey{redefsymbols}
-\AtBeginDocument{
-  \si@opt@disablekey{redefsymbols}
-    {Symbols can only be redefined\MessageBreak
-     when loading siunitx}}
-\newlength\si@eVcorra
-\newlength\si@eVcorrb
-\si@opt@key{eVcorra}{\setlength\si@eVcorra{#1}}
-\si@opt@key{eVcorrb}{\setlength\si@eVcorrb{#1}}
-\si@opt@xchoicekey{tophrase}{to,dots,ndash,dash}{to}
-\si@opt@boolkey{trapambigrange}
-\si@opt@cmdkeys{openrange,closerange}
-\si@opt@key{locale}{%
-  \si@loc@load{#1}%
-  \si@loc@set{#1}}%
-\si@opt@key{loctolang}{\si@loc@ltol{#1}}
-\si@opt@compatkey{units}{ugly}
-\si@opt@compatkey{units}{nice}
-\si@opt@compatkey{units}{loose}
-\si@opt@compatkey{units}{tight}
-\si@opt@compatkey{unitsdef}{OHM}
-\si@opt@compatkey{unitsdef}{ohm}
-\si@opt@compatkey{unitsdef}{redef-gensymb}
-\newif\ifsi@gensymb
-\si@opt@compatkey{unitsdef}{LITER}
-\si@opt@compatkey{unitsdef}{liter}
-\si@opt@compatkey{unitsdef}{noxspace}
-\si@opt@compatkey{unitsdef}{noconfig}
-\si@opt@compatkey{unitsdef}{noabbr}
-\si@opt@compatkey{unitsdef}{noampereageabbr}
-\si@opt@compatkey{unitsdef}{nofrequncyabbr}
-\si@opt@compatkey{unitsdef}{nomolabbr}
-\si@opt@compatkey{unitsdef}{novoltageabbr}
-\si@opt@compatkey{unitsdef}{novolumeabbr}
-\si@opt@compatkey{unitsdef}{noweightabbr}
-\si@opt@compatkey{unitsdef}{noenergyabbr}
-\si@opt@compatkey{unitsdef}{nolengthabbr}
-\si@opt@compatkey{unitsdef}{notimeabbr}
-\si@opt@compatkey{SIunits}{cdot}
-\si@opt@compatkey{SIunits}{thickspace}
-\si@opt@compatkey{SIunits}{mediumspace}
-\si@opt@compatkey{SIunits}{thinspace}
-\si@opt@compatkey{SIunits}{thickqspace}
-\si@opt@compatkey{SIunits}{mediumqspace}
-\si@opt@compatkey{SIunits}{thinqspace}
-\si@opt@compatkey{SIunits}{amssymb}
-\si@opt@compatkey{SIunits}{squaren}
-\si@opt@compatkey{SIunits}{pstricks}
-\si@opt@compatkey{SIunits}{Gray}
-\si@opt@compatkey{SIunits}{italian}
-\si@opt@compatkey{SIunits}{textstyle}
-\si@opt@compatkey{SIunits}{binary}
-\si@opt@compatkey{SIunits}{noams}
-\si@opt@compatkey{SIunits}{derivedinbase}
-\si@opt@compatkey{SIunits}{derived}
-\si@opt@compatkey{hepunits}{noprefixcmds}
-\si@opt@compatkey{fancynum}{english}
-\si@opt@compatkey{fancynum}{french}
-\si@opt@compatkey{fancynum}{tight}
-\si@opt@compatkey{fancynum}{loose}
-\si@opt@compatkey{fancynum}{thinspaces}
-\si@opt@compatkey{fancynum}{commas}
-\si@opt@compatkey{fancynum}{plain}
-\si@opt@compatkey{fancyunits}{spaceqspace}
-\newcommand*{\si@fix@thin}{\,}
-\newcommand*{\si@fix@med}{\:}
-\newcommand*{\si@fix@medium}{\:}
-\newcommand*{\si@fix@thick}{\;}
-\newcommand*{\si@fix@space}{\text{ }}
-\newcommand*{\si@fix@cdot}{{}\cdot{}}
-\newcommand*{\si@fix@comma}{{,}}
-\newcommand*{\si@fix@stop}{{.}}
-\newcommand*{\si@fix@fullstop}{{.}}
-\newcommand*{\si@fix@period}{{.}}
-\newcommand*{\si@fix@times}{\times}
-\newcommand*{\si@fix@tighttimes}{\bgroup\times\egroup}
-\newcommand*{\si@fix@tightcdot}{\bgroup\cdot\egroup}
-\newcommand*{\si@fix@plus}{+}
-\newcommand*{\si@fix@minus}{-}
-\newcommand*{\si@fix@pm}{\pm}
-\newcommand*{\si@fix@tightpm}{\bgroup\pm\egroup}
-\newcommand*{\si@fix@mp}{\mp}
-\newcommand*{\si@fix@two}{2}
-\newcommand*{\si@fix@ten}{10}
-\newcommand*{\si@fix@slash}{/}
-\newcommand*{\si@fix@none}{}
-\newcommand*{\si@fix@to}{ to }
-\newcommand*{\si@fix@dash}{--}
-\newcommand*{\si@fix@dots}{\,\dots\,}
-\newcommand*{\si@symbol}[1]{%
-  \expandafter\protected\expandafter\def
-    \csname si@sym@#1\endcsname{%
-    \ifmmode
-      \expandafter\csname si@maths#1\expandafter\endcsname
-    \else
-      \expandafter\csname si@text#1\expandafter\endcsname
-    \fi}}
-\si@symbol{Omega}
-\si@symbol{ringA}
-\si@symbol{mu}
-\si@symbol{degree}
-\si@symbol{minute}
-\si@symbol{second}
-\si@symbol{celsius}
-\AtBeginDocument{%
-  \ifsi@redefsymbols
-    \@ifpackageloaded{textcomp}
-      {\si@log@debug{Redefining symbols using textcomp}%
-       \renewcommand*{\si@textdegree}{\textdegree}%
-       \renewcommand*{\si@mathsdegree}{\text{\textdegree}}%
-       \@ifpackageloaded{mathptmx}{}
-         {\renewcommand*{\si@textmu}{\textmu}%
-          \renewcommand*{\si@textOmega}{\textohm}}%
-       \renewcommand*{\si@tempa}{OT1}%
-       \ifx\si@tempa\encodingdefault
-         \renewcommand*{\si@mathsringA}{%
-           \text{\capitalring{A}}}%
-         \renewcommand*{\si@textringA}{\capitalring{A}}
-       \fi}{}
-    \@ifpackageloaded{upgreek}
-      {\si@log@debug{Redefining symbols using upgreek}%
-       \renewcommand*{\si@mathsOmega}{\Upomega}}{}
-  \fi}
-\newcommand*{\si@frc@frac}[2]{%
-  \ensuremath{\si@frc@hook\frac{%
-    \expandafter\si@unt@out\expandafter{#1}}%
-    {\expandafter\si@unt@out\expandafter{#2}}}}
-\let\si@frac\si@frc@frac
-\newcommand*{\si@frc@hook}{}
-\newcommand*{\si@frc@slash}[2]{%
-    \expandafter\si@unt@out\expandafter{#1}%
-    \si@out{\ensuremath{\si@slash}}%
-    \expandafter\si@unt@out\expandafter{#2}}
-\newcommand*{\si@frc@nice}[2]{%
-  \ensuremath{\si@frc@nicefrac{\expandafter\si@unt@out%
-    \expandafter{#1}}{\expandafter\si@unt@out\expandafter
-      {#2}}}}
-\newcommand*{\si@frc@sfrac}[2]{%
-    \sfrac{\expandafter\si@unt@out\expandafter{#1}}%
-      {\expandafter\si@unt@out\expandafter{#2}}}
-\AtBeginDocument{
-  \@ifpackageloaded{xfrac}
-    {}
-    {\si@log@inf{xfrac package unavailable\MessageBreak
-       using `fraction=sfrac' will fall back on\MessageBreak
-       nicefrac-like method}%
-     \renewcommand*{\si@frc@sfrac}[2]{%
-      \si@log@warn{xfrac package unavailable}%
-      \si@frc@nice{#1}{#2}}}}
-\newlength\si@frc@displen
-\newlength\si@frc@textlen
-\newlength\si@frc@suplen
-\newlength\si@frc@ssuplen
-\newcommand*{\si@frc@nicefrac}{%
-  \ifmmode
-    \expandafter\si@frc@mathsnf
-  \else
-    \expandafter\si@frc@textnf
-  \fi}
-\newcommand*{\si@frc@mathsnf}[2]{%
-  \begingroup
-    \settoheight{\si@frc@displen}{\ensuremath{%
-      \displaystyle{M}}}%
-    \settoheight{\si@frc@textlen}{\ensuremath{%
-      \textstyle{M}}}%
-    \settoheight{\si@frc@suplen}{\ensuremath{%
-      \scriptstyle{M}}}%
-    \settoheight{\si@frc@ssuplen}{%
-      \ensuremath{\scriptscriptstyle{M}}}%
-    \addtolength{\si@frc@displen}{-\si@frc@ssuplen}%
-    \addtolength{\si@frc@textlen}{-\si@frc@ssuplen}%
-    \addtolength{\si@frc@suplen}{-\si@frc@ssuplen}%
-    \mathchoice
-      {\raisebox{\si@frc@displen}{\ensuremath{%
-        \scriptstyle{#1}}}}%
-      {\raisebox{\si@frc@textlen}{\ensuremath{%
-         \scriptstyle{#1}}}}%
-      {\raisebox{\si@frc@suplen}%
-        {\ensuremath{\scriptscriptstyle{#1}}}}%
-      {\raisebox{\si@frc@ssuplen}%
-        {\ensuremath{\scriptscriptstyle{#1}}}}%
-    \mkern-2mu\relax/\mkern-1mu\relax
-    \bgroup
-      \mathchoice
-        {\scriptstyle}%
-        {\scriptstyle}%
-        {\scriptscriptstyle}%
-        {\scriptscriptstyle}%
-      {#2}%
-    \egroup
-  \endgroup}
-\newcommand*{\si@frc@textnf}[2]{%
-  \begingroup
-    \settoheight{\si@frc@textlen}{M}%
-    \settoheight{\si@frc@ssuplen}{\fontsize\sf@size\z@\relax
-      \selectfont{M}}%
-    \addtolength{\si@frc@textlen}{-\si@frc@ssuplen}%
-    \raisebox{\si@frc@textlen}{\fontsize\sf@size\z@\relax
-      \selectfont{#1}}%
-    \hspace{-0.25ex}/\hspace{-0.25ex}%
-    \hbox{\fontsize\sf@size\z@\selectfont{#2}}%
-  \endgroup}
-\newcommand*{\si@frc@ugly}[1]{%
-  \renewcommand*{\si@tempa}{#1}%
-  \ifmmode
-    \expandafter\si@frc@frac
-  \else
-    \renewcommand*{\si@tempb}{1}%
-    \ifx\si@tempa\si@tempb
-      \setbox\si@tempboxa=\hbox{\ensuremath{\si@valuesep}}%
-      \hskip-\wd\si@tempboxa\relax
-      \renewcommand*{\si@tempa}{}%
-    \fi
-    \expandafter\si@frc@slash
-  \fi
-  {\si@tempa}}
-\g@addto@macro{\document}{%
-  \ifdefined\mathsf
-    \setbox\si@tempboxa=\hbox{%
-      $\mathsf{\global\chardef\si@fam@sf=\fam}$}%
-  \else
-    \si@log@inf{\string\mathsf not found}%
-    \global\chardef\si@fam@sf=99\relax
-  \fi
-  \ifdefined\mathtt
-    \setbox\si@tempboxa=\hbox{%
-      $\mathtt{\global\chardef\si@fam@tt=\fam}$}%
-  \else
-    \si@log@inf{\string\mathtt not found}%
-    \global\chardef\si@fam@tt=99\relax
-  \fi}
-\newcommand*\si@fam@detect@default{%
-  \edef\si@tempa{\familydefault}%
-  \edef\si@tempb{\sfdefault}%
-  \ifx\si@tempa\si@tempb
-    \@ifpackageloaded{cmbright}{}{\sisetup{ mathsrm = mathsf}}%
-    \sisetup{ textrm = sffamily }%
-  \fi
-  \edef\si@tempb{\ttdefault}%
-  \ifx\si@tempa\si@tempb
-    \sisetup
+\RequirePackage{expl3}
+\ProvidesExplPackage {siunitx} {2010/05/23} {2.0}
+  {A comprehensive (SI) units package}
+\msg_set:nnnn { siunitx } { incompatible-package }
+  { Package~'#1'~incompatible. }
+  { The~#1~package~and~siunitx~are~incompatible. }
+\cs_set_protected_nopar:Npn \_siunitx_load_check:n #1 {
+  \group_begin:
+    \@ifpackageloaded {#1}
+      { \msg_error:nnx { siunitx } { incompatible-package } {#1} }
+      { }
+  \group_end:
+}
+\clist_map_function:nN
+  { SIunits , sistyle , siunits , SIstyle , unitsdef , fancyunits }
+  \_siunitx_load_check:n
+\AtBeginDocument {
+  \clist_map_function:nN { SIunits , sistyle , siunits , SIstyle }
+    \_siunitx_load_check:n
+}
+\RequirePackage{ amstext , array , l3keys2e }
+\cs_set:Npn \_siunitx_tmp:w { }
+\bool_new:N \_l_siunitx_tmp_bool
+\box_new:N \_l_siunitx_tmp_box
+\int_new:N \_l_siunitx_tmp_int
+\tl_new:N \_l_siunitx_tmpa_tl
+\tl_new:N \_l_siunitx_tmpb_tl
+\bool_new:N \_l_siunitx_error_bool
+\cs_set_protected:Npn \_siunitx_error:nxx #1#2#3 {
+  \bool_set_true:N \_l_siunitx_error_bool
+  \msg_error:nnxx { siunitx } {#1} {#2} {#3}
+}
+\cs_set_protected:Npn \_siunitx_error:nx #1#2 {
+  \_siunitx_error:nxx {#1} {#2} { }
+}
+\cs_set_protected:Npn \_siunitx_error:n #1 {
+  \_siunitx_error:nxx {#1} { } { }
+}
+\cs_generate_variant:Nn \_siunitx_error:nx { nV }
+\AtBeginDocument {
+  \cs_if_free:cT { T@TS1 }
+    {
+      \DeclareFontEncoding { TS1 } { } { }
+      \DeclareFontSubstitution { TS1 } { cmr } { m } { n }
+    }
+}
+\DeclareTextSymbolDefault \_c_siunitx_minus_tl { TS1 }
+\DeclareTextSymbol \_c_siunitx_minus_tl { TS1 } { 61 }
+\DeclareTextSymbol \_c_siunitx_mu_tl { TS1 } { 181 }
+\DeclareTextSymbolDefault \_c_siunitx_mu_tl { TS1 }
+\tl_new:N \_c_siunitx_omega_tl
+\tl_set:Nn \_c_siunitx_omega_tl { \Omega }
+\AtBeginDocument {
+  \cs_if_exist:NT \upOmega
+    { \tl_set:Nn \_c_siunitx_omega_tl { \upOmega } }
+}
+\cs_set_protected:Npn \_siunitx_tl_put_left_math:Nn #1#2 {
+  \tl_put_left:Nn #1 { \_siunitx_ensuremath:n {#2} }
+}
+\cs_generate_variant:Nn \_siunitx_tl_put_left_math:Nn { NV }
+\cs_generate_variant:Nn \_siunitx_tl_put_left_math:Nn { cV }
+\cs_set_protected:Npn \_siunitx_tl_put_right_math:Nn #1#2 {
+  \tl_put_right:Nn #1 { \_siunitx_ensuremath:n {#2} }
+}
+\cs_generate_variant:Nn \_siunitx_tl_put_right_math:Nn { NV }
+\cs_generate_variant:Nn \_siunitx_tl_put_right_math:Nn { cV }
+\keys_define:nn { siunitx } {
+  unknown .code:n =
+    {
+      \msg_error:nnx { siunitx } { unknown-option }
+        { \exp_not:V \l_keys_key_tl }
+    }
+}
+\clist_new:N \_l_siunitx_option_deactivate_clist
+\cs_set_protected_nopar:Npn \_siunitx_option_deactivate:n #1 {
+  \clist_put_right:Nn \_l_siunitx_option_deactivate_clist {#1}
+}
+\cs_set_protected_nopar:Npn \_siunitx_option_deactivate_aux:n #1 {
+  \keys_define:nn { siunitx }
+    {
+      #1 .code:n =
+        { \msg_warning:nnx { siunitx } { option-preamble-only } {#1} }
+    }
+}
+\AtBeginDocument {
+  \clist_map_function:NN \_l_siunitx_option_deactivate_clist
+    \_siunitx_option_deactivate_aux:n
+}
+\cs_generate_variant:Nn \prop_del:Nn { c }
+\cs_generate_variant:Nn \prop_put:Nnn { cnV }
+\cs_generate_variant:Nn \tl_replace_all_in:Nnn { NnV }
+\group_begin:
+\tl_map_inline:nn { \M \A \C \R \O }
+  { \char_make_other:n { `#1 } }
+\tl_map_inline:nn { \F \N \T }
+  { \char_set_lccode:nn { `#1 } { `#1 } }
+\tl_to_lowercase:n {
+  \group_end:
+  \prg_new_conditional:Nnn \_siunitx_cs_if_tl:N { T , TF }
+    {
+      \exp_after:wN \_siunitx_cs_if_tl_aux:w
+        \token_to_meaning:N #1 MACRO \q_nil
+          {
+            \cs_if_exist:cTF { \cs_to_str:N #1 ~ }
+              { \prg_return_false: }
+              { \prg_return_true: }
+          }
+          { \prg_return_false: }
+    }
+  \cs_set_nopar:Npn \_siunitx_cs_if_tl_aux:w #1 MACRO #2 \q_nil
+    { \tl_if_empty:nTF {#1} }
+  \prg_new_conditional:Nnn \_siunitx_cs_if_macro:N { T }
+    {
+      \exp_after:wN \_siunitx_cs_if_tl_aux:w
+        \token_to_meaning:N #1 MACRO \q_nil
+          { \prg_return_true: }
+          { \prg_return_false: }
+    }
+}
+\cs_set_eq:NN \_siunitx_ensuremath:n \ensuremath
+\AtBeginDocument {
+  \@ifpackageloaded { tex4ht }
+    {
+      \cs_set_eq:NN \_siunitx_ensuremath:n \use:n
+      \keys_set:nn { siunitx } { mode = text }
+    }
+    { }
+}
+\cs_set_protected_nopar:Npn \_siunitx_set_math_fam:n #1 {
+  \int_new:c { _c_siunitx_math #1 _int }
+  \group_begin:
+    \hbox_set:Nn \_l_siunitx_tmp_box
+      {
+        \ensuremath
+          {
+            \use:c { math #1 }
+              {
+                \int_gset:cn { _c_siunitx_math #1 _int } { \fam }
+              }
+          }
+      }
+  \group_end:
+}
+\tl_put_right:Nn \document {
+  \_siunitx_set_math_fam:n { sf }
+  \_siunitx_set_math_fam:n { tt }
+}
+\cs_set_protected_nopar:Npn \_siunitx_set_text_fam:n #1 {
+  \tl_new:c { _c_siunitx_text #1 _tl }
+  \tl_set:cx { _c_siunitx_text #1 _tl } { \use:c { #1 default } }
+}
+\AtBeginDocument {
+  \_siunitx_set_text_fam:n { sf }
+  \_siunitx_set_text_fam:n { tt }
+}
+\tl_new:N \_l_siunitx_detect_inline_weight_tl
+\keys_define:nn { siunitx } {
+  detect-all .choice:,
+  detect-all .default:n = true,
+  detect-all / false .meta:n =
+    {
+      detect-family = false,
+      detect-italic = false,
+      detect-mode   = false,
+      detect-weight = false
+    },
+  detect-all / true .meta:n =
+    {
+      detect-family = true,
+      detect-italic = true,
+      detect-mode   = true,
+      detect-weight = true
+    },
+  detect-display-math  .bool_set:N =
+    \_l_siunitx_detect_display_math_bool,
+  detect-family        .bool_set:N = \_l_siunitx_detect_family_bool,
+  detect-inline-weight .choice:,
+  detect-inline-weight .value_required:,
+  detect-inline-weight /
+    combined           .code:n =
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { combined } },
+  detect-inline-weight /
+    math               .code:n     =
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { math } },
+  detect-inline-weight /
+    text               .code:n     =
+      { \tl_set:Nn \_l_siunitx_detect_inline_weight_tl { text } },
+  detect-italic        .bool_set:N = \_l_siunitx_detect_italic_bool,
+  detect-mode          .bool_set:N = \_l_siunitx_detect_mode_bool,
+  detect-none          .choice:,
+  detect-none          .default:n = true,
+  detect-none / false .meta:n =
+    {
+      detect-family = true,
+      detect-italic = true,
+      detect-mode   = true,
+      detect-weight = true
+    },
+  detect-none / true .meta:n =
+    {
+      detect-family = false,
+      detect-italic = false,
+      detect-mode   = false,
+      detect-weight   = false
+    },
+  detect-weight        .bool_set:N = \_l_siunitx_detect_weight_bool
+}
+\bool_new:N \_l_siunitx_font_set_bool
+\bool_new:N \_l_siunitx_font_math_mode_bool
+\tl_new:N \_l_siunitx_font_family_tl
+\cs_set_nopar:Npn \_siunitx_font_italic: { }
+\cs_set_nopar:Npn \_siunitx_font_weight: { }
+\cs_set_protected_nopar:Npn \_siunitx_detect_font: {
+  \bool_if:NF \_l_siunitx_font_set_bool
+    {
+      \_siunitx_detect_font_init:
+      \bool_if:NT \_l_siunitx_detect_weight_bool
+        { \_siunitx_detect_font_weight: }
+      \bool_if:NT \_l_siunitx_detect_family_bool
+        { \_siunitx_detect_font_family: }
+      \bool_if:NT \_l_siunitx_detect_italic_bool
+        { \_siunitx_detect_font_italic: }
+      \bool_if:NT \_l_siunitx_detect_mode_bool
+        { \_siunitx_detect_font_mode: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_init: {
+  \bool_set_true:N \_l_siunitx_font_set_bool
+  \cs_set:Npn \_siunitx_font_weight:
+    {
+      \unboldmath
+      \mdseries
+    }
+  \cs_set:Npn \_siunitx_font_italic: { \upshape }
+  \tl_set:Nn \_l_siunitx_font_family_tl { rm }
+  \bool_set_true:N \_l_siunitx_font_math_mode_bool
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight: {
+  \mode_if_math:TF
+    {
+      \mode_if_inner:TF
+        {
+          \use:c
+            {
+              _siunitx_detect_font_weight_
+              \_l_siunitx_detect_inline_weight_tl
+              :
+            }
+        }
+        {
+          \bool_if:NTF \_l_siunitx_detect_display_math_bool
+            { \_siunitx_detect_font_weight_math: }
+            { \_siunitx_detect_font_weight_text: }
+        }
+    }
+    { \_siunitx_detect_font_weight_text: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_combined: {
+  \_siunitx_detect_font_weight_math:
+  \_siunitx_detect_font_weight_text:
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_math: {
+  \tl_if_eq:nVT { bold } \math@version
+    {
+      \cs_set:Npn \_siunitx_font_weight:
+        {
+          \boldmath
+          \bfseries
+        }
+    }
+  \tl_if_eq:nVT { light } \math@version
+    {
+      \cs_set:Npn \_siunitx_font_weight:
+        { \lseries }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_weight_text: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl { \exp_args:NV \tl_head_i:n \f@series }
+  \tl_if_eq:nVT { b } \_l_siunitx_tmpa_tl
+    {
+      \cs_set:Npn \_siunitx_font_weight:
+        {
+          \boldmath
+          \bfseries
+        }
+    }
+  \tl_if_eq:nVT { l } \_l_siunitx_tmpa_tl
+    {
+      \cs_set:Npn \_siunitx_font_weight:
+        { \lseries }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family: {
+  \_siunitx_detect_font_family_text:
+  \bool_if:NT \_l_siunitx_detect_display_math_bool
+    {
+      \mode_if_math:T
+        { \mode_if_inner:F { \_siunitx_detect_font_family_math: } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family_math: {
+  \tl_set:Nn \_l_siunitx_font_family_tl { rm }
+  \intexpr_compare:nNnT
+    { \int_use:N \fam } = { \int_use:N \_c_siunitx_mathsf_int }
+    { \tl_set:Nn \_l_siunitx_font_family_tl { sf } }
+  \intexpr_compare:nNnT
+    { \int_use:N \fam } = { \int_use:N \_c_siunitx_mathtt_int }
+    { \tl_set:Nn \_l_siunitx_font_family_tl { tt } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_family_text: {
+  \tl_if_eq:NNT \f@family \_c_siunitx_textsf_tl
+    { \tl_set:Nn \_l_siunitx_font_family_tl { sf } }
+  \tl_if_eq:NNT \f@family \_c_siunitx_texttt_tl
+    { \tl_set:Nn \_l_siunitx_font_family_tl { tt } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_italic: {
+  \tl_if_eq:nVT { it } \f@shape
+    { \cs_set_nopar:Npn \_siunitx_font_italic: { \itshape } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_detect_font_mode: {
+  \mode_if_math:F
+    { \bool_set_false:N \_l_siunitx_font_math_mode_bool }
+}
+\bool_new:N \_l_siunitx_number_math_mode_bool
+\bool_new:N \_l_siunitx_unit_math_mode_bool
+\cs_set:Npn \_siunitx_number_mathrm:n #1 { }
+\cs_set:Npn \_siunitx_number_mathsf:n #1 { }
+\cs_set:Npn \_siunitx_number_mathtt:n #1 { }
+\cs_set_nopar:Npn \_siunitx_number_textrm: { }
+\cs_set_nopar:Npn \_siunitx_number_textsf: { }
+\cs_set_nopar:Npn \_siunitx_number_texttt: { }
+\keys_define:nn { siunitx } {
+  number-color  .tl_set:N    = \_l_siunitx_number_color_tl,
+  number-math-rm .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_mathrm:n ##1 { #1 {##1} } },
+  number-math-sf .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_mathsf:n ##1 { #1 {##1} } },
+  number-math-tt .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_mathtt:n ##1 { #1 {##1} } },
+  number-mode .choice:,
+  number-mode / math .code:n =
+    { \bool_set_true:N \_l_siunitx_number_math_mode_bool },
+  number-mode / text .code:n =
+    { \bool_set_false:N \_l_siunitx_number_math_mode_bool },
+  number-text-rm .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_textrm: {#1} },
+  number-text-sf .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_textsf: {#1} },
+  number-text-tt .code:n  =
+    { \cs_set_nopar:Npn \_siunitx_number_texttt: {#1} }
+}
+\cs_set_nopar:Npn \_siunitx_unit_mathrm: { }
+\cs_set_nopar:Npn \_siunitx_unit_mathsf: { }
+\cs_set_nopar:Npn \_siunitx_unit_mathtt: { }
+\cs_set_nopar:Npn \_siunitx_unit_textrm: { }
+\cs_set_nopar:Npn \_siunitx_unit_textsf: { }
+\cs_set_nopar:Npn \_siunitx_unit_texttt: { }
+\keys_define:nn { siunitx } {
+  unit-color  .tl_set:N  = \_l_siunitx_unit_color_tl,
+  unit-math-rm .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_mathrm:n ##1 { #1 {##1} } },
+  unit-math-sf .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_mathsf:n ##1 { #1 {##1} } },
+  unit-math-tt .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_mathtt:n ##1 { #1 {##1} } },
+  unit-mode .choice:,
+  unit-mode / math .code:n =
+    { \bool_set_true:N \_l_siunitx_unit_math_mode_bool },
+  unit-mode / text .code:n =
+    { \bool_set_false:N \_l_siunitx_unit_math_mode_bool },
+  unit-text-rm .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_textrm: {#1} },
+  unit-text-sf .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_textsf: {#1} },
+  unit-text-tt .code:n =
+    { \cs_set_nopar:Npn \_siunitx_unit_texttt: {#1} }
+}
+\keys_define:nn { siunitx } {
+  color .meta:n =
+    {
+      number-color = #1,
+      unit-color   = #1
+    },
+  math-rm .meta:n =
+    {
+      number-math-rm = #1,
+      unit-math-rm   = #1
+    },
+  math-sf .meta:n =
+    {
+      number-math-sf = #1,
+      unit-math-sf   = #1
+    },
+  math-tt .meta:n =
+    {
+      number-math-tt = #1,
+      unit-math-tt   = #1
+    },
+  mode .choice:,
+  mode / math .meta:n =
+    {
+      number-mode = math,
+      unit-mode   = math
+    },
+  mode / text .meta:n =
+    {
+      number-mode = text,
+      unit-mode   = text
+    },
+  text-rm .meta:n =
+    {
+      number-text-rm = #1,
+      unit-text-rm   = #1
+    },
+  text-sf .meta:n =
+    {
+      number-text-sf = #1,
+      unit-text-sf   = #1
+    },
+  text-tt .meta:n =
+    {
+      number-text-tt = #1,
+      unit-text-tt   = #1
+    }
+}
+\keys_set:nn { siunitx } {
+  math-rm     = \mathrm,
+  math-sf     = \mathsf,
+  math-tt     = \mathtt,
+  number-mode = math,
+  text-rm     = \rmfamily,
+  text-sf     = \sffamily,
+  text-tt     = \ttfamily,
+}
+\AtBeginDocument {
+  \tl_set:Nx \_l_siunitx_tmpa_tl { \familydefault }
+  \tl_if_eq:NNT \_l_siunitx_tmpa_tl \_c_siunitx_textsf_tl
+    {
+      \@ifpackageloaded { cmbright } { }
+        { \keys_set:nn { siunitx } { math-rm = \mathsf } }
+      \keys_set:nn { siunitx } { text-rm  = \sffamily }
+    }
+  \tl_if_eq:NNT \_l_siunitx_tmpa_tl \_c_siunitx_texttt_tl
+    {
+      \keys_set:nn { siunitx }
+        {
+          math-rm = \mathtt,
+          text-rm  = \ttfamily
+        }
+    }
+}
+\tl_new:N \_l_siunitx_print_arg_tl
+\tl_new:N \_l_siunitx_print_type_tl
+\cs_set_protected:Npn \_siunitx_print:nn #1#2 {
+  \group_begin:
+    \tl_set:Nn \_l_siunitx_print_type_tl {#1}
+    \tl_set:Nn \_l_siunitx_print_arg_tl {#2}
+    \_siunitx_detect_font:
+    \bool_if:NF \_l_siunitx_detect_mode_bool
+      {
+        \bool_if:cTF { _l_siunitx_ #1 _math_mode_bool }
+          { \bool_set_true:N \_l_siunitx_font_math_mode_bool }
+          { \bool_set_false:N \_l_siunitx_font_math_mode_bool }
+      }
+    \_siunitx_print_aux:
+  \group_end:
+}
+\cs_generate_variant:Nn \_siunitx_print:nn { nV }
+\cs_set_protected_nopar:Npn \_siunitx_print_aux: {
+  \text
+    {
+      \_siunitx_print_color:
+      \_siunitx_font_weight:
+      \_siunitx_font_italic:
+      \use:c
+        {
+          _siunitx_ \_l_siunitx_print_type_tl _
+          text \_l_siunitx_font_family_tl :
+        }
+      \bool_if:NTF \_l_siunitx_font_math_mode_bool
+        { \_siunitx_print_math: }
+        { \_siunitx_print_text: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_print_color: {
+  \tl_if_empty:cF { _l_siunitx_ \_l_siunitx_print_type_tl _color_tl }
+    {
+      \color
+        {
+          \tl_use:c { _l_siunitx_ \_l_siunitx_print_type_tl _color_tl }
+        }
+    }
+}
+\AtBeginDocument {
+  \@ifpackageloaded { color } { }
+    { \cs_set_eq:NN \_siunitx_print_color: \scan_stop: }
+}
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+  \char_set_lccode:nn { `\! } { `\_ }
+  \char_make_active:N \!
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected_nopar:Npn \_siunitx_print_math:
+    {
+      \ensuremath
+        {
+          \use:c
+            {
+              _siunitx_ \_l_siunitx_print_type_tl _
+              math \_l_siunitx_font_family_tl :n
+            }
+              { \_l_siunitx_print_arg_tl }
+        }
+    }
+  \cs_set_protected_nopar:Npn \_siunitx_print_text:
+    {
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { @ }
+        { \_siunitx_print_text_sub:n }
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { ! }
+        { \_siunitx_print_text_sub:n }
+      \tl_replace_all_in:Nnn \_l_siunitx_print_arg_tl { ^ }
+        { \_siunitx_print_text_super:n }
+      \_l_siunitx_print_arg_tl
+    }
+}
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected:Npn \_siunitx_print_text_sub:n #1
+    {
+      \cs_set:Npn \_siunitx_print_text_sub_super:n ##1
+        {
+          \ensuremath
+            {
+              @ { \text {#1} }
+              ^ { \text {##1} }
+            }
+        }
+      \peek_meaning_remove:NTF \_siunitx_print_text_super:n
+        { \_siunitx_print_text_sub_super:n }
+        { \ensuremath { @ { \text {#1} } } }
+    }
+}
+\cs_set_protected:Npn \_siunitx_print_text_sub_super:n { }
+\cs_set_protected:Npn \_siunitx_print_text_super:n #1 {
+  \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+  \tl_replace_all_in:Nnn \_l_siunitx_tmpa_tl { - }
+    { \_c_siunitx_minus_tl }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \exp_not:N \ensuremath
+        {
+          ^ { \exp_not:N \text { \exp_not:V \_l_siunitx_tmpa_tl } }
+        }
+    }
+  \_l_siunitx_tmpa_tl
+}
+\keys_define:nn { siunitx } {
+  input-product  .tl_set:N = \_l_siunitx_input_product_tl,
+  input-quotient .tl_set:N = \_l_siunitx_input_quotient_tl,
+}
+\keys_set:nn { siunitx } {
+  input-product  = x,
+  input-quotient = /
+}
+\tl_new:N \_l_siunitx_number_arg_tl
+\tl_new:N \_l_siunitx_number_next_tl
+\tl_new:N \_l_siunitx_number_multi_tl
+\tl_new:N \_l_siunitx_number_denominator_tl
+\tl_new:N \_l_siunitx_number_numerator_tl
+\cs_set_protected:Npn \_siunitx_number_preprocess:n #1 {
+  \_siunitx_number_preprocess_init:
+  \tl_set:Nn \_l_siunitx_number_arg_tl {#1}
+  \_siunitx_number_preprocess_product:
+  \tl_if_empty:NT \_l_siunitx_number_multi_tl
+    { \_siunitx_number_preprocess_quotient: }
+}
+\cs_generate_variant:Nn \_siunitx_number_preprocess:n { V }
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_init: {
+  \bool_set_false:N \_l_siunitx_error_bool
+  \tl_clear:N \_l_siunitx_number_multi_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_product: {
+  \tl_map_function:NN \_l_siunitx_input_product_tl
+    \_siunitx_number_preprocess_product_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_preprocess_product_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_number_arg_tl {#1}
+    {
+      \cs_set:Npn \_siunitx_tmp:w ##1 #1 ##2 \q_stop
+        {
+          \tl_set:Nn \_l_siunitx_number_arg_tl {##1}
+          \tl_set:Nn \_l_siunitx_number_next_tl {##2}
+          \tl_set:Nn \_l_siunitx_number_multi_tl { product }
+        }
+      \exp_after:wN \_siunitx_tmp:w \_l_siunitx_number_arg_tl \q_stop
+      \tl_if_empty:NT \_l_siunitx_number_arg_tl
+        { \_siunitx_error:n { starting-product-token } }
+      \tl_if_empty:NT \_l_siunitx_number_next_tl
+        { \_siunitx_error:n { ending-product-token } }
+      \tl_map_break:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_preprocess_quotient: {
+  \tl_map_function:NN \_l_siunitx_input_quotient_tl
+    \_siunitx_number_preprocess_quotient_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_preprocess_quotient_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_number_arg_tl {#1}
+    {
+      \cs_set:Npn \_siunitx_tmp:w ##1 #1 ##2 \q_stop
+        {
+          \tl_set:Nn \_l_siunitx_number_numerator_tl {##1}
+          \tl_set:Nn \_l_siunitx_number_denominator_tl {##2}
+          \tl_set:Nn \_l_siunitx_number_multi_tl { quotient }
+        }
+      \exp_after:wN \_siunitx_tmp:w \_l_siunitx_number_arg_tl \q_stop
+      \tl_if_empty:NT \_l_siunitx_number_numerator_tl
+        { \_siunitx_error:n { starting-quotient-token } }
+      \tl_if_empty:NT \_l_siunitx_number_denominator_tl
+        { \_siunitx_error:n { ending-quotient-token } }
+      \tl_if_in:NnT \_l_siunitx_number_denominator_tl {#1}
+        { \_siunitx_error:n { duplicate-quotient-token } }
+      \tl_map_break:
+    }
+}
+\tl_new:N \_c_siunitx_number_part_complex_tl
+\tl_set:Nn \_c_siunitx_number_part_complex_tl { complex }
+\bool_new:N \_l_siunitx_number_in_complex_bool
+\bool_new:N \_l_siunitx_number_in_complex_root_bool
+\bool_new:N \_l_siunitx_number_in_decimal_bool
+\bool_new:N \_l_siunitx_number_in_exponent_bool
+\bool_new:N \_l_siunitx_number_in_first_bool
+\bool_new:N \_l_siunitx_number_in_sign_bool
+\bool_new:N \_l_siunitx_number_in_uncert_bool
+\bool_new:N \_l_siunitx_number_in_value_bool
+\prop_new:N \_l_siunitx_number_in_prop
+\tl_new:N \_l_siunitx_number_parsed_tl
+\tl_new:N \_l_siunitx_number_part_tl
+\tl_new:N \_l_siunitx_number_part_decimal_tl
+\tl_new:N \_l_siunitx_number_part_decimal_marker_tl
+\tl_new:N \_l_siunitx_number_part_integer_tl
+\tl_new:N \_l_siunitx_number_part_sign_tl
+\tl_new:N \_l_siunitx_number_part_uncert_tl
+\keys_define:nn { siunitx } {
+  input-close-uncertainty .tl_set:N = \_l_siunitx_input_uncert_close_tl,
+  input-complex-roots     .tl_set:N = \_l_siunitx_input_complex_tl,
+  input-decimal-markers   .tl_set:N = \_l_siunitx_input_decimal_tl,
+  input-digits            .tl_set:N = \_l_siunitx_input_digit_tl,
+  input-exponent-markers  .tl_set:N = \_l_siunitx_input_exponent_tl,
+  input-ignore            .tl_set:N = \_l_siunitx_input_ignore_tl,
+  input-open-uncertainty  .tl_set:N = \_l_siunitx_input_uncert_open_tl,
+  input-protect-tokens    .tl_set:N = \_l_siunitx_input_protect_tl,
+  input-signs             .tl_set:N = \_l_siunitx_input_sign_tl,
+  input-symbols           .tl_set:N = \_l_siunitx_input_symbol_tl,
+}
+\keys_set:nn { siunitx } { % (
+  input-close-uncertainty = ),
+  input-complex-roots     = ij,
+  input-decimal-markers   = {.,},
+  input-digits            = 0123456789,
+  input-exponent-markers  = dDeE,
+  input-open-uncertainty  = (, % )
+  input-protect-tokens    = \mp\pi\pm,
+  input-signs             = +-\mp\pm,
+  input-symbols           = \pi,
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse:n #1 {
+  \tl_if_empty:nF {#1}
+    {
+      \_siunitx_number_in_init:
+      \cs_set_eq:NN \_siunitx_number_in_parse_more:N
+        \_siunitx_number_in_parse_mantissa_aux:N
+      \_siunitx_number_in_parse_aux:n {#1}
+    }
+}
+\cs_generate_variant:Nn \_siunitx_number_in_parse:n { V }
+\cs_set_protected:Npn \_siunitx_number_in_parse_aux:n #1 {
+  \tl_set_rescan:Nnx \_l_siunitx_number_arg_tl
+    {
+      \_siunitx_number_in_protect:
+      \char_make_ignore:N \~
+      \char_make_other:N \,
+      \char_make_other:N \.
+      \cs_set_eq:NN \, \prg_do_nothing:
+    }
+    {#1}
+  \_siunitx_number_in_sign_replace:N \_l_siunitx_number_arg_tl
+  \tl_map_function:NN \_l_siunitx_number_arg_tl
+    \_siunitx_number_in_parse_loop:N
+  \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+    {
+      \bool_if:NTF \_l_siunitx_number_in_uncert_bool
+        { \_siunitx_error:nx { invalid-number } {#1} }
+        {
+          \prop_put:NVn \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_tl { true }
+          \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+            {
+              \prop_put:NVV \_l_siunitx_number_in_prop
+                \_l_siunitx_number_part_decimal_tl
+                \_l_siunitx_number_parsed_tl
+            }
+            {
+              \prop_put:NVV \_l_siunitx_number_in_prop
+                \_l_siunitx_number_part_integer_tl
+                \_l_siunitx_number_parsed_tl
+            }
+       }
+    }
+  \_siunitx_number_in_check:n {#1}
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_init: {
+  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+    \_siunitx_number_in_parse_mantissa:N
+  \cs_set_eq:NN \_siunitx_number_in_check:n
+    \_siunitx_number_in_check_short:n
+  \tl_clear:N \_l_siunitx_number_parsed_tl
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \bool_set_false:N \_l_siunitx_error_bool
+  \bool_set_false:N \_l_siunitx_number_in_complex_bool
+  \bool_set_false:N \_l_siunitx_number_in_complex_root_bool
+  \bool_set_false:N \_l_siunitx_number_in_exponent_bool
+  \bool_set_false:N \_l_siunitx_number_in_uncert_bool
+  \_siunitx_number_in_init_part:n { mantissa }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_init_part:n #1 {
+  \bool_set_false:N \_l_siunitx_number_in_decimal_bool
+  \bool_set_true:N \_l_siunitx_number_in_first_bool
+  \bool_set_false:N \_l_siunitx_number_in_sign_bool
+  \bool_set_false:N \_l_siunitx_number_in_value_bool
+  \tl_set:Nn \_l_siunitx_number_part_tl {#1}
+  \tl_set:Nn \_l_siunitx_number_part_decimal_tl { #1 -decimal }
+  \tl_set:Nn \_l_siunitx_number_part_decimal_marker_tl
+    { #1 -decimal-marker }
+  \tl_set:Nn \_l_siunitx_number_part_integer_tl { #1 -integer }
+  \tl_set:Nn \_l_siunitx_number_part_sign_tl { #1 -sign }
+  \tl_set:Nn \_l_siunitx_number_part_uncert_tl { #1 -uncertainty }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_protect: {
+  \tl_map_function:NN \_l_siunitx_input_protect_tl
+    \_siunitx_number_in_protect_aux:N
+}
+\cs_set_protected:Npn \_siunitx_number_in_protect_aux:N #1 {
+  \cs_set_eq:NN #1 \scan_stop:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_sign_replace:N #1 {
+  \tl_replace_all_in:Nnn #1 { -+ } { \mp }
+  \tl_replace_all_in:Nnn #1 { +- } { \pm }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_error:nx #1#2 {
+  \_siunitx_error:nx {#1} { \exp_not:n {#2} }
+  \tl_map_break:
+}
+\cs_generate_variant:Nn \_siunitx_number_in_parse_error:nx { nV }
+\cs_set_protected:Npn \_siunitx_number_in_parse_loop:N #1 { }
+\cs_set_protected:Npn \_siunitx_number_in_parse_more:N #1 { }
+\cs_set_protected:Npn \_siunitx_number_in_parse_restricted:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    {
+      \_siunitx_number_in_parse_error:nx
+        { restricted-number } {#1}
+    }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        {
+          \_siunitx_number_in_parse_error:nV
+            { restricted-number } \_l_siunitx_number_arg_tl
+        }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            {
+              \_siunitx_number_in_parse_error:nV
+                { restricted-number } \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \_siunitx_number_in_parse_error:nV
+                    { restricted-number } \_l_siunitx_number_arg_tl
+                }
+                {
+                  \_siunitx_number_in_parse_error:nx
+                    { restricted-number } {#1}
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_complex:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    {
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+        \_siunitx_number_in_parse_mantissa:N
+      \_siunitx_number_in_exponent:N #1
+    }
+    {
+      \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+        {
+          \_siunitx_number_in_parse_error:nV
+            { misplaced-complex-root-token }
+            \_l_siunitx_number_arg_tl
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_exponent:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    {
+      \_siunitx_number_in_parse_error:nx
+        { duplicate-exponent-token } { \token_to_str:N #1 }
+    }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        {
+          \_siunitx_number_in_parse_error:nV
+            { invalid-token-in-exponent } \_l_siunitx_number_arg_tl
+        }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            {
+              \_siunitx_number_in_parse_error:nV
+                { invalid-token-in-exponent } \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \_siunitx_number_in_parse_error:nV
+                    { invalid-token-in-exponent }
+                    \_l_siunitx_number_arg_tl
+                }
+                {
+                  \_siunitx_number_in_parse_error:nx
+                    { invalid-token-in-number } {#1}
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_mantissa:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_digit_tl {#1}
+    { \_siunitx_number_in_digit:N #1 }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_decimal_tl {#1}
+        { \_siunitx_number_in_decimal:N #1 }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+            { \_siunitx_number_in_sign:N #1 }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_symbol_tl {#1}
+                {
+                  \prop_put:Nnn \_l_siunitx_number_in_prop { symbolic }
+                    { true }
+                  \_siunitx_number_in_digit:N #1
+                }
+                {
+                  \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+                    { \_siunitx_number_in_parse_more:N #1 }
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_mantissa_aux:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    { \_siunitx_number_in_exponent:N #1 }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_uncert_open_tl {#1}
+        { \_siunitx_number_in_uncert_open:N #1 }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl {#1}
+            {
+              \_siunitx_number_in_parse_error:nx
+                { misplaced-uncertainty-token } {#1}
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                { \_siunitx_number_in_complex:N #1 }
+                {
+                  \_siunitx_number_in_parse_error:nx
+                    { invalid-token-in-number } {#1}
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_uncert:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_digit_tl {#1}
+    { \_siunitx_number_in_digit:N #1 }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_decimal_tl {#1}
+        {
+          \_siunitx_number_in_parse_error:nV
+            { invalid-token-in-uncertainty }
+            \_l_siunitx_number_arg_tl
+        }
+        {
+          \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+            {
+              \_siunitx_number_in_parse_error:nV
+                { invalid-token-in-uncertainty }
+                \_l_siunitx_number_arg_tl
+            }
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_symbol_tl {#1}
+                {
+                  \prop_put:Nnn \_l_siunitx_number_in_prop { symbolic }
+                    { true }
+                  \_siunitx_number_in_digit:N #1
+                }
+                {
+                  \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+                    {
+                      \tl_if_in:NnTF \_l_siunitx_input_uncert_close_tl
+                        {#1}
+                        { \_siunitx_number_in_uncert_close:N #1 }
+                        {
+                          \_siunitx_number_in_parse_error:nV
+                            { invalid-token-in-uncertainty }
+                            \_l_siunitx_number_arg_tl
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_parse_uncert_after:N #1 {
+  \tl_if_in:NnTF \_l_siunitx_input_exponent_tl {#1}
+    {
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+        \_siunitx_number_in_parse_mantissa:N
+      \_siunitx_number_in_exponent:N #1
+    }
+    {
+      \tl_if_in:NnTF \_l_siunitx_input_sign_tl {#1}
+        {
+          \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+            \_siunitx_number_in_parse_mantissa:N
+          \_siunitx_number_in_sign:N #1
+        }
+        {
+          \tl_if_in:NnF \_l_siunitx_input_ignore_tl {#1}
+            {
+              \tl_if_in:NnTF \_l_siunitx_input_complex_tl {#1}
+                {
+                  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+                    \_siunitx_number_in_parse_mantissa:N
+                  \_siunitx_number_in_complex:N #1
+                }
+                {
+                  \_siunitx_number_in_parse_error:nV { invalid-number }
+                    \_l_siunitx_number_arg_tl
+                }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_complex:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_complex_root_bool
+    {
+      \_siunitx_number_in_parse_error:nx
+        { duplicate-complex-root-token } { \token_to_str:N #1 }
+    }
+    {
+      \cs_set_eq:NN \_siunitx_number_in_check:n
+        \_siunitx_number_in_check_full:n
+      \bool_set_true:N \_l_siunitx_number_in_complex_root_bool
+      \prop_put:Nnn \_l_siunitx_number_in_prop { complex-root } {#1}
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+        {
+          \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+            \_siunitx_number_in_parse_complex:N
+        }
+      \bool_if:NT \_l_siunitx_number_in_decimal_bool
+        {
+          \bool_if:NF \_l_siunitx_number_in_complex_bool
+            {
+              \prop_if_in:NnT \_l_siunitx_number_in_prop
+                { mantissa-uncertainty }
+                {
+                  \_siunitx_number_in_complex_aux:nn
+                    { mantissa-decimal } { complex-decimal }
+                  \_siunitx_number_in_complex_aux:nn
+                    { mantissa-uncertainty } { complex-uncertainty }
+                }
+              \_siunitx_number_in_complex_aux:nn { mantissa-integer }
+                { complex-integer }
+              \_siunitx_number_in_complex_aux:nn
+                { mantissa-decimal-marker } { complex-decimal-marker }
+              \prop_del:Nn \_l_siunitx_number_in_prop { mantissa }
+              \prop_put:Nnn \_l_siunitx_number_in_prop { complex }
+                { true }
+            }
+        }
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { mantissa-sign }
+            {
+              \_siunitx_number_in_complex_aux:nn { mantissa-sign }
+                { complex-sign }
+            }
+        }
+      \bool_set_true:N \_l_siunitx_number_in_complex_bool
+      \bool_set_false:N \_l_siunitx_number_in_first_bool
+      \_siunitx_number_in_init_part:n { complex }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop
+        { complex-decimal-marker }
+        { \bool_set_true:N \_l_siunitx_number_in_decimal_bool }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop
+        { complex-sign }
+        { \bool_set_true:N \_l_siunitx_number_in_sign_bool }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_complex_aux:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_del:Nn  \_l_siunitx_number_in_prop {#1}
+      \prop_put:NnV \_l_siunitx_number_in_prop {#2} \_l_siunitx_tmpa_tl
+   }
+}
+\cs_set_protected:Npn \_siunitx_number_in_decimal:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+    {
+      \_siunitx_number_in_parse_error:nx { duplicate-decimal-token }
+        { \token_to_str:N #1 }
+    }
+    {
+      \bool_set_true:N \_l_siunitx_number_in_decimal_bool
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+        {
+          \prop_put:NVn \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_tl { true }
+          \prop_put:NVV \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_integer_tl
+            \_l_siunitx_number_parsed_tl
+          \tl_clear:N \_l_siunitx_number_parsed_tl
+        }
+      \prop_put:NVn \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_decimal_marker_tl {#1}
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_digit:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \bool_if:NTF \_l_siunitx_number_in_uncert_bool
+    { \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1} }
+    {
+      \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+        {
+          \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1}
+          \tl_if_eq:nnF {#1} { 0 }
+            { \bool_set_true:N \_l_siunitx_number_in_value_bool }
+        }
+        {
+          \tl_if_eq:nnTF {#1} { 0 }
+            {
+              \prop_put:NVn \_l_siunitx_number_in_prop
+                \_l_siunitx_number_part_tl { true }
+              \prop_put:NVn \_l_siunitx_number_in_prop
+                \_l_siunitx_number_part_integer_tl { 0 }
+            }
+            { \bool_set_true:N \_l_siunitx_number_in_value_bool }
+          \bool_if:NT \_l_siunitx_number_in_value_bool
+            { \tl_put_right:Nn \_l_siunitx_number_parsed_tl {#1} }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_exponent:N #1 {
+  \bool_if:NTF \_l_siunitx_number_in_exponent_bool
+    {
+      \_siunitx_number_in_parse_error:nx { duplicate-exponent-token }
+        { \token_to_str:N #1 }
+    }
+    {
+      \cs_set_eq:NN \_siunitx_number_in_parse_more:N
+        \_siunitx_number_in_parse_exponent:N
+      \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+        { \_siunitx_number_in_store: }
+      \bool_set_true:N \_l_siunitx_number_in_exponent_bool
+      \_siunitx_number_in_init_part:n { exponent }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_sign:N #1 {
+  \bool_if:NTF \_l_siunitx_number_in_first_bool
+    {
+      \bool_set_false:N \_l_siunitx_number_in_first_bool
+      \bool_set_true:N \_l_siunitx_number_in_sign_bool
+      \prop_put:NVn \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_sign_tl {#1}
+    }
+    {
+      \bool_if:NTF \_l_siunitx_number_in_exponent_bool
+        {
+          \_siunitx_number_in_parse_error:nx { misplaced-sign-token }
+            {#1}
+        }
+        {
+          \bool_if:NTF \_l_siunitx_number_in_complex_bool
+            {
+              \_siunitx_number_in_parse_error:nx
+                { misplaced-sign-token } {#1}
+            }
+            {
+              \tl_if_empty:NF \_l_siunitx_number_parsed_tl
+                { \_siunitx_number_in_store: }
+              \cs_set_eq:NN \_siunitx_number_in_check:n
+                \_siunitx_number_in_check_full:n
+              \_siunitx_number_in_init_part:n { complex }
+              \prop_put:Nnn \_l_siunitx_number_in_prop
+                { complex-sign } {#1}
+              \bool_set_true:N \_l_siunitx_number_in_complex_bool
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_in_uncert_open:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_first_bool
+  \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+    \_siunitx_number_in_parse_uncert:N
+  \bool_set_true:N \_l_siunitx_number_in_uncert_bool
+  \tl_if_empty:NTF \_l_siunitx_number_parsed_tl
+    {
+      \prop_if_in:NVF \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_integer_tl
+        {
+          \_siunitx_number_in_parse_error:nV { invalid-number }
+            \_l_siunitx_number_arg_tl
+        }
+    }
+    { \_siunitx_number_in_store: }
+}
+\cs_set_protected:Npn \_siunitx_number_in_uncert_close:N #1 {
+  \bool_set_false:N \_l_siunitx_number_in_uncert_bool
+  \tl_if_empty:NTF \_l_siunitx_number_parsed_tl
+    {
+      \_siunitx_number_in_parse_error:nV { empty-uncertainty }
+        \_l_siunitx_number_arg_tl
+    }
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_uncert_tl \_l_siunitx_number_parsed_tl
+      \prop_put:Nnn \_l_siunitx_number_in_prop
+        { uncertainty } { true }
+      \tl_clear:N \_l_siunitx_number_parsed_tl
+      \cs_set_eq:NN \_siunitx_number_in_parse_loop:N
+        \_siunitx_number_in_parse_uncert_after:N
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_store: {
+  \prop_put:NVn \_l_siunitx_number_in_prop \_l_siunitx_number_part_tl
+    { true }
+  \bool_if:NTF \_l_siunitx_number_in_decimal_bool
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_decimal_tl \_l_siunitx_number_parsed_tl
+    }
+    {
+      \prop_put:NVV \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_integer_tl \_l_siunitx_number_parsed_tl
+    }
+  \tl_clear:N \_l_siunitx_number_parsed_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check:n #1 { }
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check_short:n #1 {
+  \prop_if_in:NVF \_l_siunitx_number_in_prop
+    \_l_siunitx_number_part_integer_tl
+    {
+      \prop_if_in:NVF \_l_siunitx_number_in_prop
+        \_l_siunitx_number_part_decimal_tl
+        { \_siunitx_error:nx { invalid-number } {#1} }
+    }
+  \bool_if:NF \_l_siunitx_number_in_value_bool
+    {
+      \tl_if_eq:NNF \_l_siunitx_number_part_tl
+        \_c_siunitx_number_part_complex_tl
+        {
+          \prop_get:NVN \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_sign_tl  \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+            {
+              \tl_set:Nx \_l_siunitx_tmpb_tl
+                { \_l_siunitx_number_part_sign_tl -deleted }
+              \prop_put:NVV \_l_siunitx_number_in_prop
+                \_l_siunitx_tmpb_tl \_l_siunitx_tmpa_tl
+            }
+          \prop_del:NV \_l_siunitx_number_in_prop
+            \_l_siunitx_number_part_sign_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_in_check_full:n #1 {
+  \tl_if_eq:NNF \_l_siunitx_number_part_tl
+    \_c_siunitx_number_part_complex_tl
+    { \_siunitx_number_in_check_short:n {#1} }
+  \bool_if:NF \_l_siunitx_number_in_complex_root_bool
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { complex-sign }
+        \_l_siunitx_tmpa_tl
+      \_siunitx_error:nV { misplaced-sign-token } \_l_siunitx_tmpa_tl
+    }
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+        {
+          \prop_del:Nn \_l_siunitx_number_in_prop { mantissa-sign }
+          \prop_put:NnV \_l_siunitx_number_in_prop { complex-sign }
+            \_l_siunitx_tmpa_tl
+        }
+    }
+}
+\int_new:N \_l_siunitx_round_int
+\tl_new:N \_l_siunitx_round_tl
+\bool_new:N \_l_siunitx_round_bool
+\tl_new:N \_l_siunitx_round_decimal_in_tl
+\tl_new:N \_l_siunitx_round_decimal_out_tl
+\tl_new:N \_l_siunitx_round_integer_in_tl
+\tl_new:N \_l_siunitx_round_integer_out_tl
+\int_new:N \_l_siunitx_process_decimal_int
+\int_new:N \_l_siunitx_process_uncertainty_int
+\tl_new:N \_l_siunitx_uncertainty_decimal_tl
+\tl_new:N \_l_siunitx_uncertainty_integer_tl
+\keys_define:nn { siunitx } {
+  add-decimal-zero  .bool_set:N = \_l_siunitx_process_decimal_zero_bool,
+  add-integer-zero  .bool_set:N = \_l_siunitx_process_integer_zero_bool,
+  explicit-sign     .tl_set:N   = \_l_siunitx_process_sign_tl,
+  retain-explicit-plus  .bool_set:N = \_l_siunitx_process_plus_tl,
+  retain-unity-mantissa .bool_set:N =
+    \_l_siunitx_process_unity_mantissa_bool,
+  retain-zero-exponent .bool_set:N =
+    \_l_siunitx_process_zero_exponent_bool,
+  round-mode        .choice: ,
+  round-mode / figures .code:n =
+    { \tl_set:Nn \_l_siunitx_round_tl { figures } },
+  round-mode / off     .code:n = { \tl_clear:N \_l_siunitx_round_tl },
+  round-mode / places  .code:n =
+    { \tl_set:Nn \_l_siunitx_round_tl { places } },
+  round-precision      .int_set:N = \_l_siunitx_process_precision_int,
+}
+\keys_set:nn { siunitx } {
+  add-decimal-zero      = true,
+  add-integer-zero      = true,
+  retain-unity-mantissa = true,
+  round-precision       = 2,
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process: {
+  \_siunitx_number_process_sign:
+  \_siunitx_number_process_zero_fill:
+  \_siunitx_number_process_mantissa:
+  \prop_if_in:NnF \_l_siunitx_number_in_prop { symbolic }
+    {
+      \_siunitx_number_process_exponent:
+      \_siunitx_number_process_uncertainty:
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { uncertainty }
+        { \_siunitx_number_process_round: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_exponent: {
+  \bool_if:NF \_l_siunitx_process_zero_exponent_bool
+    {
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        {
+          \bool_set_false:N \_l_siunitx_tmp_bool
+          \_siunitx_number_process_exponent_aux:n { integer }
+          \bool_if:NF \_l_siunitx_tmp_bool
+            { \_siunitx_number_process_exponent_aux:n { decimal } }
+          \bool_if:NF \_l_siunitx_tmp_bool
+            {
+              \prop_del:Nn \_l_siunitx_number_in_prop { exponent }
+              \prop_del:Nn \_l_siunitx_number_in_prop
+                { exponent-integer }
+              \prop_del:Nn \_l_siunitx_number_in_prop
+                { exponent-decimal }
+             }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_exponent_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { exponent- #1 }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \intexpr_compare:nNnF
+        { \_l_siunitx_tmpa_tl } = { 0 }
+        { \bool_set_true:N \_l_siunitx_tmp_bool }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop {#1}
+    { \_siunitx_number_process_figures_aux:n {#1} }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_aux:n #1 {
+  \_siunitx_number_process_figures_init:n {#1}
+  \_siunitx_number_process_figures_count:n { integer }
+  \_siunitx_number_process_figures_count:n { decimal }
+  \bool_if:NTF \_l_siunitx_round_bool
+    {
+      \bool_set_false:N \_l_siunitx_round_bool
+      \intexpr_compare:nNnTF
+        { \int_use:N \_l_siunitx_round_int } >
+          { \int_use:N \_l_siunitx_process_precision_int }
+        {
+          \_siunitx_number_process_figures_round:
+          \_siunitx_number_process_round_tidy:n {#1}
+        }
+        { \_siunitx_number_process_figures_pad:n {#1} }
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -integer } { 0 }
+      \prop_del:Nn \_l_siunitx_number_in_prop { #1 -decimal }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_init:n #1 {
+  \int_zero:N \_l_siunitx_round_int
+  \bool_set_false:N \_l_siunitx_round_bool
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_in_tl
+  \quark_if_no_value:NT \_l_siunitx_round_decimal_in_tl
+    { \tl_clear:N \_l_siunitx_round_decimal_in_tl }
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_in_tl
+  \quark_if_no_value:NT \_l_siunitx_round_integer_in_tl
+    { \tl_clear:N \_l_siunitx_round_integer_in_tl }
+  \tl_clear:N \_l_siunitx_round_decimal_out_tl
+  \tl_clear:N \_l_siunitx_round_integer_out_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_figures_count:n #1 {
+  \tl_if_empty:cF { _l_siunitx_round_ #1 _in_tl }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -uncertainty }
+        { \_siunitx_number_process_figures_count_aux:n {#1} }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_figures_count_aux:n #1 {
+  \int_set:Nn \_l_siunitx_tmp_int
+    { \exp_args:Nv \tl_head_i:n { _l_siunitx_round_ #1 _in_tl } }
+  \tl_set:cx { _l_siunitx_round_ #1 _in_tl }
+    { \exp_args:Nv \tl_tail:n { _l_siunitx_round_ #1 _in_tl } }
+  \tl_put_left:cV { _l_siunitx_round_ #1 _out_tl } \_l_siunitx_tmp_int
+  \bool_if:NF \_l_siunitx_round_bool
+    {
+      \intexpr_compare:nNnF
+        { \_l_siunitx_tmp_int } = { 0 }
+        { \bool_set_true:N \_l_siunitx_round_bool }
+    }
+  \bool_if:NT \_l_siunitx_round_bool
+    { \int_incr:N \_l_siunitx_round_int }
+  \tl_if_empty:cTF { _l_siunitx_round_ #1 _in_tl }
+    {
+      \tl_set_eq:cc { _l_siunitx_round_ #1 _in_tl }
+        { _l_siunitx_round_ #1 _out_tl }
+      \tl_clear:c { _l_siunitx_round_ #1 _out_tl }
+    }
+    { \_siunitx_number_process_figures_count_aux:n {#1} }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_round: {
+  \int_set:Nn \_l_siunitx_round_int
+    { \_l_siunitx_round_int - \_l_siunitx_process_precision_int }
+  \tl_if_empty:NF \_l_siunitx_round_decimal_in_tl
+    { \_siunitx_number_process_figures_round_loop: }
+  \tl_if_empty:NF \_l_siunitx_round_integer_in_tl
+    { \_siunitx_number_process_figures_integer: }
+  \bool_if:NT \_l_siunitx_round_bool
+    {
+      \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 1 }
+      \tl_if_empty:NF \_l_siunitx_round_decimal_out_tl
+        {
+          \tl_reverse:N \_l_siunitx_round_decimal_out_tl
+          \tl_set:Nx \_l_siunitx_round_decimal_out_tl
+            { \tl_tail:n \_l_siunitx_round_decimal_out_tl }
+          \tl_reverse:N \_l_siunitx_round_decimal_out_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_figures_round_loop: {
+  \_siunitx_number_process_round_decimal:
+  \tl_if_empty:NF \_l_siunitx_round_decimal_in_tl
+    { \_siunitx_number_process_figures_round_loop: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_integer: {
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_round_int } > { 0 }
+    {  \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 0 } }
+  \intexpr_compare:nNnF
+    { \int_use:N \_l_siunitx_round_int } > { 1 }
+    {
+      \int_set:Nn \_l_siunitx_tmp_int
+        { \exp_args:NV \tl_head_i:n \_l_siunitx_round_integer_in_tl }
+      \bool_if:NT \_l_siunitx_round_bool
+        { \int_incr:N \_l_siunitx_tmp_int }
+      \bool_set_false:N \_l_siunitx_round_bool
+      \intexpr_compare:nNnTF
+        { \int_use:N \_l_siunitx_round_int } = { 1 }
+        {
+          \intexpr_compare:nNnT
+            { \int_use:N \_l_siunitx_tmp_int } > { 4 }
+            { \bool_set_true:N \_l_siunitx_round_bool }
+        }
+        {
+          \intexpr_compare:nNnT
+            { \int_use:N \_l_siunitx_tmp_int } > { 10 }
+            {
+              \bool_set_true:N \_l_siunitx_round_bool
+              \int_zero:N \_l_siunitx_tmp_int
+            }
+          \tl_put_left:NV \_l_siunitx_round_integer_out_tl
+            \_l_siunitx_tmp_int
+        }
+    }
+  \int_decr:N \_l_siunitx_round_int
+  \tl_set:Nx \_l_siunitx_round_integer_in_tl
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_integer_in_tl }
+  \tl_if_empty:NF \_l_siunitx_round_integer_in_tl
+    { \_siunitx_number_process_figures_integer: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_figures_pad:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_in_tl
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_in_tl
+  \int_set:Nn \_l_siunitx_round_int
+    { \_l_siunitx_process_precision_int - \_l_siunitx_round_int }
+  \_siunitx_number_process_pad:n {#1}
+}
+\tl_new:N \_c_siunitx_unity_tl
+\tl_set:Nn \_c_siunitx_unity_tl { 1 }
+\cs_set_protected_nopar:Npn \_siunitx_number_process_mantissa: {
+  \bool_if:NF \_l_siunitx_process_unity_mantissa_bool
+    {
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        {
+          \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-integer }
+            \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+            {
+              \tl_if_eq:NNT \_c_siunitx_unity_tl \_l_siunitx_tmpa_tl
+                {
+                  \prop_if_in:NnF \_l_siunitx_number_in_prop
+                    { mantissa-decimal-marker }
+                    {
+                      \prop_del:Nn \_l_siunitx_number_in_prop
+                        { mantissa }
+                      \prop_del:Nn \_l_siunitx_number_in_prop
+                        { mantissa-integer }
+                    }
+                }
+            }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_pad:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \intexpr_while_do:nNnn
+        { \int_use:N \_l_siunitx_round_int } > { 0 }
+        {
+          \tl_put_right:Nn \_l_siunitx_tmpa_tl { 0 }
+          \int_decr:N \_l_siunitx_round_int
+        }
+      \prop_put:NnV \_l_siunitx_number_in_prop { #1 -decimal }
+        \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop {#1}
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -uncertainty }
+        { \_siunitx_number_process_places_aux_i:n {#1} }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_aux_i:n #1 {
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_process_precision_int } = { 0 }
+    { \prop_del:Nn \_l_siunitx_number_in_prop { #1 -decimal } }
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \tl_if_empty:NT \_l_siunitx_tmpa_tl
+            { \tl_set:Nn \_l_siunitx_tmpa_tl { 0 } }
+          \intexpr_compare:nNnTF
+            { \_l_siunitx_tmpa_tl } = { 0 }
+            {
+              \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -decimal }
+                { }
+              \int_set:Nn \_l_siunitx_round_int
+                { \_l_siunitx_process_precision_int }
+              \_siunitx_number_process_pad:n {#1}
+            }
+            {
+              \int_set:Nn \_l_siunitx_round_int
+                { \tl_elt_count:N \_l_siunitx_tmpa_tl }
+              \_siunitx_number_process_places_aux_ii:n {#1}
+            }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_places_aux_ii:n #1 {
+  \int_sub:Nn \_l_siunitx_round_int
+    { \_l_siunitx_process_precision_int }
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_round_int } < { 0 }
+    {
+      \int_set:Nn \_l_siunitx_round_int { - \_l_siunitx_round_int }
+      \_siunitx_number_process_pad:n {#1}
+    }
+    {
+      \_siunitx_number_process_places_init:n {#1}
+      \_siunitx_number_process_places_loop:n {#1}
+      \_siunitx_number_process_round_tidy:n {#1}
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_init:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_in_tl
+  \quark_if_no_value:NT \_l_siunitx_round_integer_in_tl
+    { \tl_clear:N \_l_siunitx_round_integer_in_tl }
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_in_tl
+  \tl_reverse:N \_l_siunitx_round_integer_in_tl
+  \tl_reverse:N \_l_siunitx_round_decimal_in_tl
+  \tl_clear:N \_l_siunitx_round_integer_out_tl
+  \tl_clear:N \_l_siunitx_round_decimal_out_tl
+  \bool_set_false:N \_l_siunitx_round_bool
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_places_loop:n #1 {
+  \tl_if_empty:NTF \_l_siunitx_round_decimal_in_tl
+    {
+      \tl_if_empty:NF \_l_siunitx_round_integer_in_tl
+        {
+          \_siunitx_number_process_places_integer:n {#1}
+          \_siunitx_number_process_places_loop:n {#1}
+        }
+      \bool_if:NT \_l_siunitx_round_bool
+        {
+          \tl_put_left:Nn \_l_siunitx_round_integer_out_tl { 1 }
+          \bool_set_false:N \_l_siunitx_round_bool
+        }
+    }
+    {
+      \_siunitx_number_process_round_decimal:
+      \_siunitx_number_process_places_loop:n {#1}
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_places_integer:n #1 {
+  \int_set:Nn \_l_siunitx_tmp_int
+    { \exp_args:NV \tl_head_i:n \_l_siunitx_round_integer_in_tl }
+  \tl_set:Nx \_l_siunitx_round_integer_in_tl
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_integer_in_tl }
+  \bool_if:NT \_l_siunitx_round_bool
+    { \int_incr:N \_l_siunitx_tmp_int }
+  \bool_set_false:N \_l_siunitx_round_bool
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_tmp_int } = { 10 }
+    {
+      \int_zero:N \_l_siunitx_tmp_int
+      \bool_set_true:N \_l_siunitx_round_bool
+    }
+  \tl_put_left:NV \_l_siunitx_round_integer_out_tl \_l_siunitx_tmp_int
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round: {
+  \tl_if_empty:NF \_l_siunitx_round_tl
+    {
+      \cs_set_nopar:Npx \_siunitx_tmp:w
+        {
+          \exp_not:N \clist_map_function:nN
+            { mantissa , complex }
+            \exp_not:c
+              { _siunitx_number_process_ \_l_siunitx_round_tl :n }
+        }
+      \_siunitx_tmp:w
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round_decimal: {
+  \intexpr_compare:nNnF
+    { \int_use:N \_l_siunitx_round_int } > { 1 }
+    { \_siunitx_number_process_round_decimal_aux: }
+  \tl_set:Nx \_l_siunitx_round_decimal_in_tl
+    { \exp_args:NV \tl_tail:n \_l_siunitx_round_decimal_in_tl }
+
+  \int_decr:N \_l_siunitx_round_int
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_round_decimal_aux: {
+  \int_set:Nn \_l_siunitx_tmp_int
+    { \exp_args:NV \tl_head_i:n \_l_siunitx_round_decimal_in_tl }
+  \bool_if:NT \_l_siunitx_round_bool
+    { \int_incr:N \_l_siunitx_tmp_int }
+  \bool_set_false:N \_l_siunitx_round_bool
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_round_int } = { 1 }
+    {
+      \intexpr_compare:nNnT
+        { \int_use:N \_l_siunitx_tmp_int } > { 4 }
+        { \bool_set_true:N \_l_siunitx_round_bool }
+    }
+    {
+      \intexpr_compare:nNnT
+        { \int_use:N \_l_siunitx_tmp_int } = { 10 }
+        {
+          \bool_set_true:N \_l_siunitx_round_bool
+          \int_zero:N \_l_siunitx_tmp_int
+        }
+      \tl_put_left:NV \_l_siunitx_round_decimal_out_tl
+        \_l_siunitx_tmp_int
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_round_tidy:n #1 {
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -integer }
+    \_l_siunitx_round_integer_out_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -decimal }
+    \_l_siunitx_round_decimal_out_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign: {
+  \bool_if:NF \_l_siunitx_process_plus_tl
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa-sign }
+        { \_siunitx_number_process_sign_plus:n { mantissa } }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { complex-sign }
+            {
+              \prop_if_in:NnF \_l_siunitx_number_in_prop { mantissa }
+                { \_siunitx_number_process_sign_plus:n { complex } }
+            }
+        }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent-sign }
+        { \_siunitx_number_process_sign_plus:n { exponent } }
+    }
+  \tl_if_empty:NF \_l_siunitx_process_sign_tl
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa }
+        { \_siunitx_number_process_sign_add:n { mantissa } }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_in_prop { complex }
+            { \_siunitx_number_process_sign_add:n { complex } }
+        }
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        { \_siunitx_number_process_sign_add:n { exponent } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign_add:n #1 {
+  \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -sign }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 -had-sign }
+        {
+          \prop_get:NnN \_l_siunitx_number_in_prop {#1}
+            \_l_siunitx_tmpa_tl
+          \tl_if_empty:NTF \_l_siunitx_tmpa_tl
+            {
+              \prop_put:NnV \_l_siunitx_number_in_prop { sign }
+                \_l_siunitx_process_sign_tl
+            }
+            {
+              \prop_put:NnV \_l_siunitx_number_in_prop { #1 -sign }
+                \_l_siunitx_process_sign_tl
+            }
+        }
+    }
+}
+\tl_new:N \_c_siunitx_plus_tl
+\tl_set:Nn \_c_siunitx_plus_tl { + }
+\cs_set_protected_nopar:Npn \_siunitx_number_process_sign_plus:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -sign }
+    \_l_siunitx_tmpa_tl
+  \tl_if_eq:NNT \_c_siunitx_plus_tl \_l_siunitx_tmpa_tl
+    {
+      \prop_del:Nn \_l_siunitx_number_in_prop { #1 -sign }
+      \prop_put:Nnn \_l_siunitx_number_in_prop { #1 -had-sign } { true }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_uncertainty: {
+  \clist_map_function:nN { mantissa , complex }
+    \_siunitx_number_process_uncertainty_aux:n
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_uncertainty_aux:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 -uncertainty }
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { #1 -decimal-marker }
+        { \_siunitx_number_process_uncertainty_decimal:n {#1} }
+        { \_siunitx_number_process_uncertainty_integer:n {#1} }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_uncertainty_decimal:n #1 {
+  \_siunitx_number_process_uncertainty_count:nn {#1} { decimal }
+  \_siunitx_number_process_uncertainty_count:nn {#1} { uncertainty }
+  \tl_clear:N \_l_siunitx_uncertainty_decimal_tl
+  \tl_clear:N \_l_siunitx_uncertainty_integer_tl
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_process_uncertainty_int }
+      > { \int_use:N \_l_siunitx_process_decimal_int }
+    { \_siunitx_number_process_uncertainty_separate: }
+    { \_siunitx_number_process_uncertainty_pad: }
+  \tl_if_empty:NF \_l_siunitx_uncertainty_integer_tl
+    {
+      \prop_put:NnV \_l_siunitx_number_in_prop
+        { #1 -uncertainty-integer }
+        \_l_siunitx_uncertainty_integer_tl
+    }
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -uncertainty-decimal }
+    \_l_siunitx_uncertainty_decimal_tl
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal-marker }
+    \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop
+    { #1 -uncertainty-decimal-marker } \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_uncertainty_count:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 - #2 }
+    \_l_siunitx_tmpa_tl
+  \int_set:cn { _l_siunitx_process_ #2 _int }
+    {  \tl_elt_count:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_uncertainty_pad: {
+  \intexpr_while_do:nNnn
+    { \int_use:N  \_l_siunitx_process_uncertainty_int }
+      < { \int_use:N \_l_siunitx_process_decimal_int }
+    {
+      \tl_put_right:Nn \_l_siunitx_uncertainty_decimal_tl {0}
+      \int_incr:N \_l_siunitx_process_uncertainty_int
+    }
+  \tl_put_right:NV \_l_siunitx_uncertainty_decimal_tl
+    \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_uncertainty_separate: {
+  \tl_map_function:NN \_l_siunitx_tmpa_tl
+    \_siunitx_number_process_uncertainty_separate_aux:N
+}
+\cs_set_protected:Npn
+  \_siunitx_number_process_uncertainty_separate_aux:N #1 {
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_process_uncertainty_int }
+      > { \int_use:N \_l_siunitx_process_decimal_int }
+    { \tl_put_right:Nn \_l_siunitx_uncertainty_integer_tl {#1} }
+    { \tl_put_right:Nn \_l_siunitx_uncertainty_decimal_tl {#1} }
+  \int_decr:N \_l_siunitx_process_uncertainty_int
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_uncertainty_integer:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -uncertainty }
+    \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_in_prop { #1 -uncertainty-integer }
+    \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_process_zero_fill: {
+  \_siunitx_number_process_zero_fill_aux:n { integer }
+  \_siunitx_number_process_zero_fill_aux:n { decimal }
+}
+\cs_set_nopar:Npn \_siunitx_number_process_zero_fill_aux:n #1 {
+  \bool_if:cT { _l_siunitx_process_ #1 _zero_bool }
+    {
+      \_siunitx_number_process_zero_fill_aux:nn { mantissa } {#1}
+      \_siunitx_number_process_zero_fill_aux:nn { complex }  {#1}
+      \_siunitx_number_process_zero_fill_aux:nn { exponent } {#1}
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_process_zero_fill_aux:nn #1#2 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 -decimal-marker }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_in_prop { #1 - #2 }
+        { \prop_put:Nnn \_l_siunitx_number_in_prop { #1 - #2 } { 0 } }
+    }
+}
+\prop_new:N \_l_siunitx_number_out_prop
+\tl_new:N \_l_siunitx_group_sep_tl
+\tl_new:N \_l_siunitx_output_decimal_tl
+\bool_new:N \_l_siunitx_complex_after_bool
+\keys_define:nn { siunitx } {
+  bracket-numbers           .bool_set:N = \_l_siunitx_brackets_bool,
+  close-bracket             .tl_set:N   = \_l_siunitx_bracket_close_tl,
+  complex-root-position     .choice:,
+  complex-root-position
+    / after-number          .code:n     =
+      { \bool_set_true:N \_l_siunitx_complex_after_bool } ,
+  complex-root-position
+    / before-number          .code:n     =
+      { \bool_set_false:N \_l_siunitx_complex_after_bool } ,
+  copy-decimal-marker       .bool_set:N =
+    \_l_siunitx_output_decimal_copy_bool,
+  exponent-base             .tl_set:N   = \_l_siunitx_exponent_base_tl,
+  exponent-product          .tl_set:N   =
+    \_l_siunitx_exponent_product_tl,
+  group-decimal-digits      .bool_set:N =
+    \_l_siunitx_group_decimal_bool,
+  group-digits              .meta:n =
+    {
+      group-decimal-digits = #1,
+      group-integer-digits = #1
+    },
+  group-four-digits         .bool_set:N = \_l_siunitx_group_four_bool,
+  group-integer-digits      .bool_set:N =
+    \_l_siunitx_group_integer_bool,
+  group-separator           .code:n     =
+    {
+      \tl_set:Nn \_l_siunitx_group_sep_tl { {#1} }
+    },
+  negative-color            .tl_set:N   = \_l_siunitx_negative_color_tl,
+  open-bracket              .tl_set:N   = \_l_siunitx_bracket_open_tl,
+  output-close-uncertainty  .tl_set:N   =
+    \_l_siunitx_output_uncert_close_tl,
+  output-complex-root       .tl_set:N   = \_l_siunitx_output_complex_tl,
+  output-decimal-marker     .code:n     =
+    {
+      \tl_set:Nn \_l_siunitx_output_decimal_tl { {#1} }
+    },
+  output-open-uncertainty   .tl_set:N   =
+    \_l_siunitx_output_uncert_open_tl,
+  separate-uncertainty      .bool_set:N = \_l_siunitx_uncert_sep_bool,
+  tight-spacing             .bool_set:N = \_l_siunitx_tight_bool,
+  uncertainty-separator     .tl_set:N   = \_l_siunitx_uncert_sep_tl,
+}
+\keys_set:nn { siunitx } {
+  bracket-numbers           = true, % (
+  close-bracket             = ),
+  complex-root-position     = after-number,
+  copy-decimal-marker       = false,
+  exponent-base             = 10,
+  exponent-product          = \times,
+  group-decimal-digits      = true,
+  group-integer-digits      = true,
+  group-separator           = \,,
+  open-bracket              = (, % ) (
+  output-close-uncertainty  = ),
+  output-complex-root       = \mathrm { i },
+  output-decimal-marker     = .,
+  output-open-uncertainty   = (, % )
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format: {
+  \prop_if_empty:NF \_l_siunitx_number_in_prop
+    {
+      \prop_clear:N \_l_siunitx_number_out_prop
+      \_siunitx_number_format_reassemble:
+      \_siunitx_number_format_complex:
+      \_siunitx_number_format_sign:n { mantissa }
+      \_siunitx_number_format_sign:n { exponent }
+      \_siunitx_number_format_color:
+      \_siunitx_number_format_final:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_brackets:n #1 {
+  \bool_if:NT \_l_siunitx_brackets_bool
+    {
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -bracket }
+        {
+          \_siunitx_number_format_brackets_aux:n {#1}
+          \prop_del:Nn \_l_siunitx_number_out_prop { #1 -bracket }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_brackets_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop { #1 -result }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    {
+      \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+    }
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_bracket_open_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_bracket_close_tl
+  \tl_if_eq:nnTF {#1} { result }
+    { \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl }
+    {
+      \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result }
+        \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_color: {
+  \tl_if_empty:NF \_l_siunitx_negative_color_tl
+    {
+      \_siunitx_number_format_color_aux:n { mantissa-sign }
+      \_siunitx_number_format_color_aux:n { sign }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_color_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \tl_if_eq:nVT { - } \_l_siunitx_tmpa_tl
+        {
+           \prop_put:NnV \_l_siunitx_number_out_prop { color }
+             \_l_siunitx_negative_color_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_complex: {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { complex-root }
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_out_prop { complex }
+        {
+          \_siunitx_number_format_brackets:n { complex }
+          \_siunitx_number_format_complex_aux:n { complex }
+          \_siunitx_number_format_complex_aux:n { complex-result }
+          \prop_if_in:NnT \_l_siunitx_number_out_prop
+            { complex-uncertainty }
+            {
+              \_siunitx_number_format_complex_aux:n
+                { complex-uncertainty }
+            }
+        }
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl
+            {
+              \exp_not:N \_siunitx_ensuremath:n
+                { \exp_not:V \_l_siunitx_output_complex_tl }
+            }
+          \prop_put:NnV \_l_siunitx_number_out_prop { complex }
+            \_l_siunitx_tmpa_tl
+        }
+        \_siunitx_number_format_join_complex:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_complex_aux:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \bool_if:NTF \_l_siunitx_complex_after_bool
+    {
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+        \_l_siunitx_output_complex_tl
+    }
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+        \_l_siunitx_output_complex_tl
+    }
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_copy:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop  {#1} \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_copy:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#2} \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final: {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { complex }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { mantissa-result }
+        {
+          \_siunitx_number_format_copy:nn { complex }
+            { mantissa-result }
+        }
+    }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { exponent }
+    {
+      \_siunitx_number_format_final_exponent:
+      \prop_if_in:NnTF \_l_siunitx_number_out_prop { mantissa-result }
+        { \_siunitx_number_format_final_combined: }
+        { \_siunitx_number_format_final_exponent_only: }
+    }
+    { \_siunitx_number_format_copy:nn { mantissa-result } { result } }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-bracket }
+    {
+      \prop_put:Nnn \_l_siunitx_number_out_prop { result-bracket }
+        { true }
+      \prop_del:Nn \_l_siunitx_number_out_prop { mantissa-bracket }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final_combined: {
+  \_siunitx_number_format_brackets:n { mantissa }
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-result }
+    \_l_siunitx_tmpa_tl
+  \tl_set_eq:NN \_l_siunitx_tmpb_tl \_l_siunitx_exponent_product_tl
+  \bool_if:NT \_l_siunitx_tight_bool
+    {
+      \tl_set:Nx \_l_siunitx_tmpb_tl
+        { { \exp_not:V \_l_siunitx_tmpb_tl } }
+    }
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpb_tl
+  \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result }
+    \_l_siunitx_tmpb_tl
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_tmpa_tl
+  \prop_put:Nnn \_l_siunitx_number_out_prop
+    { result-bracket-exponent } { true }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_final_exponent: {
+  \prop_get:NnN \_l_siunitx_number_out_prop { exponent }
+    \_l_siunitx_tmpa_tl
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+   { ^ { \exp_not:V \_l_siunitx_tmpa_tl } }
+  \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_exponent_base_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop { exponent-result }
+    \_l_siunitx_tmpa_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_format_final_exponent_only: {
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \bool_if:NT \_l_siunitx_tight_bool
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl
+            { { \exp_not:V \_l_siunitx_tmpa_tl } }
+        }
+      \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpb_tl
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl
+        \_l_siunitx_tmpa_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpb_tl
+    }
+  \_siunitx_number_format_copy:nn { exponent-result } { result }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group:n #1 {
+  \_siunitx_number_format_group_aux:nn {#1} { integer }
+  \_siunitx_number_format_group_aux:nn {#1} { decimal }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { #1 -integer }
+    { \_siunitx_number_format_copy:nn { #1 -integer } {#1} }
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -decimal-marker }
+    \_l_siunitx_tmpb_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpb_tl
+    {
+      \bool_if:NTF \_l_siunitx_output_decimal_copy_bool
+        { \tl_set:Nx \_l_siunitx_tmpb_tl { { \_l_siunitx_tmpb_tl } } }
+        {
+          \tl_set_eq:NN \_l_siunitx_tmpb_tl
+            \_l_siunitx_output_decimal_tl
+        }
+      \tl_set:Nx \_l_siunitx_tmpb_tl
+        {
+          \exp_not:N \_siunitx_ensuremath:n
+            { \exp_not:V \_l_siunitx_tmpb_tl }
+        }
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop { #1 -decimal-marker }
+        \_l_siunitx_tmpb_tl
+      \prop_get:NnN \_l_siunitx_number_out_prop { #1 -decimal }
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NT \_l_siunitx_tmpb_tl
+        { \tl_clear:N \_l_siunitx_tmpb_tl }
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_aux:nn #1#2 {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { #1 - #2 }
+    {
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { symbolic }
+        { \_siunitx_number_format_copy:n { #1 - #2 } }
+        {
+          \bool_if:cTF { _l_siunitx_group_ #2 _bool }
+            { \_siunitx_number_format_group_four:nn {#1} {#2} }
+            { \_siunitx_number_format_copy:n { #1 - #2 } }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_four:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 - #2 }
+    \_l_siunitx_tmpa_tl
+  \bool_if:NTF \_l_siunitx_group_four_bool
+    { \_siunitx_number_format_group_four_aux:nn {#1} {#2} }
+    {
+      \exp_after:wN \_siunitx_number_format_group_four_aux:NNNNNNw
+        \_l_siunitx_tmpa_tl \q_no_value \q_no_value \q_no_value
+        \q_no_value \q_no_value \q_nil
+        { \_siunitx_number_format_copy:n {#1 - #2} }
+        { \_siunitx_number_format_group_four_aux:nn {#1} {#2} }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_four_aux:NNNNNNw
+  #1#2#3#4#5#6 \q_nil {
+  \quark_if_no_value:NTF #5
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_four_aux:nn
+  #1#2 {
+  \tl_clear:N \_l_siunitx_tmpb_tl
+  \use:c { _siunitx_number_format_group_ #2 : }
+  \prop_put:NnV \_l_siunitx_number_out_prop { #1 - #2 }
+    \_l_siunitx_tmpb_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_decimal: {
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \exp_after:wN \_siunitx_number_format_group_decimal_aux:NNNN
+        \_l_siunitx_tmpa_tl { } { } { }
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_decimal_aux:NNNN
+  #1#2#3#4 {
+  \tl_if_empty:nTF {#2}
+    { \tl_put_right:Nn \_l_siunitx_tmpb_tl {#1} }
+    {
+      \tl_if_empty:nTF {#3}
+        { \tl_put_right:Nn \_l_siunitx_tmpb_tl { #1 #2 } }
+        {
+          \tl_put_right:Nn \_l_siunitx_tmpb_tl { #1 #2 #3 }
+          \tl_if_empty:nF {#4}
+            {
+              \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpb_tl
+                \_l_siunitx_group_sep_tl
+              \_siunitx_number_format_group_decimal_aux:NNNN #4
+            }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_group_integer: {
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \_siunitx_number_format_group_integer_setup:V \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_format_group_integer_setup:n #1 {
+  \_siunitx_number_format_group_integer_setup_aux:NNNN
+    { } #1 { } { } { }
+}
+\cs_generate_variant:Nn \_siunitx_number_format_group_integer_setup:n
+  { V }
+\cs_set_protected:Npn
+  \_siunitx_number_format_group_integer_setup_aux:NNNN #1#2#3#4 {
+  \tl_if_empty:nTF {#2}
+    { \_siunitx_number_format_group_integer_aux:NNNN #1 \q_nil }
+    {
+      \tl_if_empty:nTF {#3}
+        {
+          \_siunitx_number_format_group_integer_aux:NNNN { } { } #1#2
+            \q_nil
+        }
+        {
+          \tl_if_empty:nTF {#4}
+            {
+              \_siunitx_number_format_group_integer_aux:NNNN { } #1#2#3
+                \q_nil
+            }
+            {
+              \_siunitx_number_format_group_integer_setup_aux:NNNN
+                {#1#2#3#4}
+            }
+        }
+    }
+}
+\cs_set_protected:Npn
+  \_siunitx_number_format_group_integer_aux:NNNN #1#2#3#4 {
+  \tl_put_right:Nn \_l_siunitx_tmpb_tl {#1#2#3}
+  \quark_if_nil:nF {#4}
+    {
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpb_tl
+        \_l_siunitx_group_sep_tl
+      \_siunitx_number_format_group_integer_aux:NNNN #4
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_complex: {
+  \_siunitx_number_format_sign_complex:
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa }
+    {
+      \_siunitx_number_format_brackets:n { mantissa }
+      \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-result }
+        \_l_siunitx_tmpa_tl
+      \prop_get:NnN \_l_siunitx_number_out_prop { complex-result }
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NT \_l_siunitx_tmpb_tl
+        {
+          \prop_get:NnN \_l_siunitx_number_out_prop { complex }
+            \_l_siunitx_tmpb_tl
+        }
+      \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+      \prop_put:NnV \_l_siunitx_number_out_prop { mantissa-result }
+        \_l_siunitx_tmpa_tl
+      \prop_put:Nnn \_l_siunitx_number_out_prop { mantissa-bracket }
+        { true }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert: {
+  \_siunitx_number_format_join_uncert:n { mantissa }
+  \_siunitx_number_format_join_uncert:n { complex }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert:n #1 {
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1}
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_get:NnN \_l_siunitx_number_out_prop { #1 -uncertainty }
+        \_l_siunitx_tmpb_tl
+      \quark_if_no_value:NTF \_l_siunitx_tmpb_tl
+        { \_siunitx_number_format_copy:nn {#1} { #1 -result } }
+        {
+          \bool_if:NT \_l_siunitx_uncert_sep_bool
+            { \_siunitx_number_format_join_uncert_pm: }
+          \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result }
+            \_l_siunitx_tmpa_tl
+          \prop_put:Nnn \_l_siunitx_number_out_prop { #1 -bracket }
+            { true }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_join_uncert_pm: {
+  \bool_if:NTF \_l_siunitx_tight_bool
+    {
+      \tl_put_left:Nn \_l_siunitx_tmpb_tl
+        { \_siunitx_ensuremath:n { { \pm } } }
+    }
+    {
+      \tl_put_left:Nn \_l_siunitx_tmpb_tl
+        { \_siunitx_ensuremath:n { { } \pm { } } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_reassemble: {
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { mantissa }
+    {
+      \_siunitx_number_format_group:n { mantissa }
+      \_siunitx_number_format_uncertainty:n { mantissa }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { complex }
+    {
+      \_siunitx_number_format_group:n { complex }
+      \_siunitx_number_format_uncertainty:n { complex }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+    { \_siunitx_number_format_group:n { exponent } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop {#1}
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { #1 -sign }
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \bool_if:NT \_l_siunitx_tight_bool
+            {
+              \tl_set:Nx \_l_siunitx_tmpa_tl
+                { { \exp_not:V \_l_siunitx_tmpa_tl } }
+            }
+          \tl_clear:N \_l_siunitx_tmpb_tl
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl
+            \_l_siunitx_tmpa_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { #1 -sign }
+            \_l_siunitx_tmpb_tl
+          \prop_get:NnN \_l_siunitx_number_out_prop {#1}
+            \_l_siunitx_tmpa_tl
+          \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop {#1}
+            \_l_siunitx_tmpa_tl
+          \prop_get:NnN \_l_siunitx_number_out_prop { #1 -result }
+            \_l_siunitx_tmpa_tl
+          \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+            {
+              \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+              \prop_put:NnV \_l_siunitx_number_out_prop { #1 -result }
+                \_l_siunitx_tmpa_tl
+            }
+      }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign_complex: {
+  \_siunitx_number_format_sign_complex:n { complex }
+  \_siunitx_number_format_sign_complex:n { complex-result }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_sign_complex:n #1  {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop {#1}
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop { complex-sign }
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \bool_if:NTF \_l_siunitx_tight_bool
+            {
+              \tl_set:Nx \_l_siunitx_tmpa_tl
+                { { \exp_not:V \_l_siunitx_tmpa_tl } }
+            }
+            {
+              \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa }
+                {
+                  \tl_set:Nx \_l_siunitx_tmpa_tl
+                    { { } \exp_not:V \_l_siunitx_tmpa_tl { } }
+                }
+            }
+          \tl_clear:N \_l_siunitx_tmpb_tl
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpb_tl
+            \_l_siunitx_tmpa_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop { complex-sign }
+            \_l_siunitx_tmpb_tl
+          \prop_get:NnN \_l_siunitx_number_out_prop {#1}
+            \_l_siunitx_tmpa_tl
+          \tl_put_left:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \prop_put:NnV \_l_siunitx_number_out_prop {#1}
+            \_l_siunitx_tmpa_tl
+      }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_format_uncertainty:n #1 {
+  \prop_if_in:NnTF \_l_siunitx_number_in_prop { #1 -uncertainty }
+    {
+      \bool_if:NTF \_l_siunitx_uncert_sep_bool
+        { \_siunitx_number_format_uncertainty_sep:n {#1} }
+        { \_siunitx_number_format_uncertainty_joined:n {#1} }
+      \_siunitx_number_format_join_uncert:
+    }
+    { \_siunitx_number_format_copy:nn {#1} { #1 -result } }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_format_uncertainty_joined:n #1 {
+  \prop_get:NnN \_l_siunitx_number_in_prop { #1 -uncertainty }
+    \_l_siunitx_tmpa_tl
+  \prop_del:Nn \_l_siunitx_number_in_prop { #1 -uncertainty }
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_output_uncert_open_tl
+  \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_uncert_sep_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_tmpa_tl
+    \_l_siunitx_output_uncert_close_tl
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpb_tl
+  \tl_put_right:NV \_l_siunitx_tmpb_tl \_l_siunitx_tmpa_tl
+  \prop_put:NnV \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpb_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_number_format_uncertainty_sep:n #1 {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -integer }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop
+        { #1 -uncertainty-integer }
+        {
+          \prop_put:Nnn \_l_siunitx_number_out_prop
+            { #1 -uncertainty-integer } { 0 }
+        }
+    }
+    \_siunitx_number_format_group:n { #1 -uncertainty }
+    \prop_put:NnV \_l_siunitx_number_out_prop { #1 -uncertainty }
+      \_l_siunitx_tmpa_tl
+}
+\tl_new:N \_l_siunitx_number_out_tl
+\tl_new:N \_l_siunitx_number_out_saved_tl
+\tl_new:N \_l_siunitx_number_fraction_tl
+\bool_new:N \_l_siunitx_number_compound_bool
+\tl_new:N \_l_siunitx_quotient_mode_tl
+\cs_set_protected:Npn \_siunitx_fraction:nn { }
+\keys_define:nn { siunitx } {
+  fraction-function  .code:n     =
+     { \cs_set_eq:NN \_siunitx_fraction:nn #1 },
+  output-product     .tl_set:N   = \_l_siunitx_output_product_tl,
+  output-quotient    .tl_set:N   = \_l_siunitx_output_quotient_tl,
+  parse-numbers      .bool_set:N = \_l_siunitx_number_parse_bool,
+  quotient-mode      .choice:,
+  quotient-mode / fraction .code:n =
+    { \tl_set:Nn \_l_siunitx_quotient_mode_tl { fraction } },
+  quotient-mode / symbol .code:n =
+    { \tl_set:Nn \_l_siunitx_quotient_mode_tl { symbol } },
+}
+\keys_set:nn { siunitx } {
+  fraction-function = \frac,
+  output-product    = \times,
+  output-quotient   = /,
+  parse-numbers     = true,
+  quotient-mode     = symbol
+}
+\cs_set_protected:Npn \_siunitx_number_output:n #1 {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_preunit_tl
+  \_siunitx_combined_output:n {#1}
+}
+\cs_generate_variant:Nn \_siunitx_number_output:n { V }
+\cs_set_protected_nopar:Npn \_siunitx_number_output_bracket: {
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \bool_if:NT \_l_siunitx_number_compound_bool
+        { \_siunitx_number_format_brackets:n { result } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_color: {
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { color }
+    {
+      \prop_get:NnN \_l_siunitx_number_out_prop { color }
+        \_l_siunitx_number_color_tl
+    }
+}
+\cs_set_protected:Npn \_siunitx_number_output_parse:n #1 {
+  \_siunitx_number_preprocess:n {#1}
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \tl_if_empty:NTF \_l_siunitx_number_multi_tl
+        { \_siunitx_number_output_parse_aux: }
+        {
+          \use:c
+            { _siunitx_number_output_ \_l_siunitx_number_multi_tl : }
+        }
+    }
+}
+\cs_generate_variant:Nn \_siunitx_number_output_parse:n { V }
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parse_aux: {
+  \_siunitx_number_in_parse:V \_l_siunitx_number_arg_tl
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \_siunitx_number_process:
+      \prop_if_in:NnT \_l_siunitx_number_in_prop { exponent }
+        { \bool_set_true:N \_l_siunitx_brackets_bool }
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+      \bool_if:NTF \_l_siunitx_brackets_bool
+        { \_siunitx_number_output_single: }
+        {
+          \prop_if_in:NnTF \_l_siunitx_number_out_prop
+            { result-bracket }
+            { \_siunitx_number_output_parts: }
+            { \_siunitx_number_output_single: }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts: {
+  \bool_if:nTF
+    {
+      \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+      \tl_if_empty_p:N \_l_siunitx_unit_tl
+    }
+    { \_siunitx_number_output_single: }
+    { \_siunitx_number_output_parts_aux: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_aux: {
+  \bool_if:NTF \_l_siunitx_multi_repeat_bool
+    {
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+        {
+          \_siunitx_number_output_parts_aux:n { mantissa }
+          \_siunitx_number_output_parts_aux:n { complex }
+        }
+      \prop_get:NnN \_l_siunitx_number_out_prop { exponent-result }
+        \_l_siunitx_tmpa_tl
+      \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+        {
+          \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+            {
+              \tl_set_eq:NN \_l_siunitx_tmpb_tl
+                \_l_siunitx_exponent_product_tl
+              \bool_if:NT \_l_siunitx_tight_bool
+                {
+                  \tl_set:Nx \_l_siunitx_tmpb_tl
+                    { { \exp_not:V \_l_siunitx_tmpb_tl } }
+                }
+              \_siunitx_tl_put_left_math:NV \_l_siunitx_tmpa_tl
+                \_l_siunitx_tmpb_tl
+              \prop_put:NnV \_l_siunitx_number_out_prop { exponent }
+                \_l_siunitx_tmpa_tl
+            }
+          \_siunitx_number_output_parts_print:n { exponent }
+        }
+    }
+    { \_siunitx_number_output_single: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_aux:n #1 {
+   \prop_if_in:NnT \_l_siunitx_number_out_prop {#1}
+     { \_siunitx_number_output_parts_print:n {#1} }
+   \prop_if_in:NnT \_l_siunitx_number_out_prop { #1 -uncertainty }
+     {
+        \bool_if:NTF \_l_siunitx_tight_bool
+          {
+            \_siunitx_print:nn { number }
+              { \_siunitx_ensuremath:n { { \pm } } }
+          }
+          {
+            \_siunitx_print:nn { number }
+              { \_siunitx_ensuremath:n { { } \pm { } } }
+          }
+       \_siunitx_number_output_parts_print:n { #1 -uncertainty }
+     }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_parts_print:n #1 {
+  \_siunitx_unit_output_pre_print:
+  \prop_get:NnN \_l_siunitx_number_out_prop {#1} \_l_siunitx_tmpa_tl
+  \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+  \_siunitx_unit_output_print:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product: {
+  \bool_if:NTF \_l_siunitx_product_brackets_bool
+    {
+      \bool_if:nTF
+        {
+          \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+          \tl_if_empty_p:N \_l_siunitx_unit_tl
+        }
+        { \_siunitx_number_output_product_aux: }
+        { \_siunitx_number_output_product_brackets: }
+    }
+    {
+      \bool_if:NTF \_l_siunitx_product_repeat_bool
+        { \_siunitx_number_output_product_aux: }
+        {
+          \_siunitx_unit_output_pre_print:
+          \tl_set_eq:NN \_l_siunitx_unit_saved_tl \_l_siunitx_unit_tl
+          \tl_clear:N \_l_siunitx_pre_unit_tl
+          \tl_clear:N \_l_siunitx_unit_tl
+          \group_begin:
+            \_siunitx_number_output_product_aux:
+          \group_end:
+          \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_saved_tl
+          \_siunitx_unit_output_print:
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product_brackets: {
+  \_siunitx_unit_output_pre_print:
+  \_siunitx_print:nn { number }
+    { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+  \nobreak
+  \tl_set_eq:NN \_l_siunitx_unit_saved_tl \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_pre_unit_tl
+  \tl_clear:N \_l_siunitx_unit_tl
+  \_siunitx_number_output_product_aux:
+  \nobreak
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_saved_tl
+  \_siunitx_print:nn { number }
+    { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+  \_siunitx_unit_output_print:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_product_aux: {
+  \bool_set_true:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_preprocess:V \_l_siunitx_number_arg_tl
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \tl_if_empty:NTF \_l_siunitx_number_multi_tl
+        { \_siunitx_number_output_parse_aux: }
+        { \_siunitx_number_output_quotient: }
+      \tl_if_empty:NF \_l_siunitx_number_next_tl
+        {
+          \bool_if:NTF \_l_siunitx_tight_bool
+            {
+              \_siunitx_print:nn { number }
+                {
+                  \_siunitx_ensuremath:n
+                    { \_l_siunitx_output_product_tl }
+                }
+            }
+            {
+              \_siunitx_print:nn  { number }
+                {
+                  \_siunitx_ensuremath:n
+                    { { } \_l_siunitx_output_product_tl { } }
+                }
+            }
+          \_siunitx_number_output_parse:V \_l_siunitx_number_next_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient: {
+  \use:c
+    { _siunitx_number_output_quotient_ \_l_siunitx_quotient_mode_tl : }
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_fraction: {
+  \bool_set_false:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_output_quotient_aux_i:
+  \tl_set:Nx \_l_siunitx_number_out_tl
+    { { \exp_not:V \_l_siunitx_number_numerator_tl } }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { { \exp_not:V \_l_siunitx_number_denominator_tl } }
+  \tl_put_right:NV \_l_siunitx_number_out_tl \_l_siunitx_tmpa_tl
+  \tl_put_left:Nn \_l_siunitx_number_out_tl { \_siunitx_fraction:nn }
+  \tl_set:Nx \_l_siunitx_number_out_tl
+    {
+      \exp_not:N \ensuremath
+        { \exp_not:V \_l_siunitx_number_out_tl }
+    }
+  \_siunitx_number_output_single_aux:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_symbol: {
+  \bool_set_true:N \_l_siunitx_number_compound_bool
+  \_siunitx_number_output_quotient_aux_i:
+  \tl_set_eq:NN \_l_siunitx_number_out_tl
+    \_l_siunitx_number_numerator_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_number_out_tl
+    \_l_siunitx_output_quotient_tl
+  \tl_put_right:NV \_l_siunitx_number_out_tl
+    \_l_siunitx_number_denominator_tl
+  \_siunitx_number_output_single_aux:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_aux_i: {
+  \_siunitx_number_in_parse:V \_l_siunitx_number_numerator_tl
+  \_siunitx_number_output_quotient_aux_ii:
+  \_siunitx_number_output_color:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_number_numerator_tl
+  \_siunitx_number_in_parse:V \_l_siunitx_number_denominator_tl
+  \_siunitx_number_output_quotient_aux_ii:
+  \prop_if_in:NnT \_l_siunitx_number_out_prop
+    { result-bracket-exponent }
+    {
+      \prop_put:Nnn \_l_siunitx_number_out_prop { result-bracket }
+        { true }
+    }
+  \_siunitx_number_output_bracket:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_number_denominator_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_quotient_aux_ii: {
+  \_siunitx_number_process:
+  \_siunitx_number_format:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_single: {
+  \bool_if:nF
+    {
+      \tl_if_empty_p:N \_l_siunitx_pre_unit_tl &&
+      \tl_if_empty_p:N \_l_siunitx_unit_tl
+    }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { exponent }
+        { \_siunitx_number_format_brackets:n { result } }
+    }
+  \_siunitx_number_output_bracket:
+  \prop_get:NnN \_l_siunitx_number_out_prop { result }
+    \_l_siunitx_number_out_tl
+  \_siunitx_number_output_single_aux:
+}
+\cs_set_protected_nopar:Npn \_siunitx_number_output_single_aux: {
+  \_siunitx_unit_output_pre_print:
+  \_siunitx_print:nV { number } \_l_siunitx_number_out_tl
+  \_siunitx_unit_output_print:
+}
+\bool_new:N \_l_siunitx_angle_degree_space_bool
+\bool_new:N \_l_siunitx_angle_minute_space_bool
+\box_new:N \_l_siunitx_angle_marker_box
+\box_new:N \_l_siunitx_angle_unit_box
+\dim_new:N \_l_siunitx_angle_marker_dim
+\dim_new:N \_l_siunitx_angle_unit_dim
+\prop_new:N \_l_siunitx_angle_degree_prop
+\prop_new:N \_l_siunitx_angle_minute_prop
+\prop_new:N \_l_siunitx_angle_second_prop
+\keys_define:nn { siunitx } {
+  add-arc-degree-zero       .bool_set:N =
+    \_l_siunitx_angle_degree_zero_bool  ,
+  add-arc-minute-zero       .bool_set:N =
+    \_l_siunitx_angle_minute_zero_bool  ,
+  add-arc-second-zero       .bool_set:N =
+    \_l_siunitx_angle_second_zero_bool  ,
+  angle-symbol-over-decimal .bool_set:N =
+    \_l_siunitx_angle_astronomy_bool    ,
+  arc-separator             .tl_set:N   =
+    \_l_siunitx_angle_arc_separator_tl  ,
+  number-angle-separator    .tl_set:N   =
+    \_l_siunitx_angle_unit_separator_tl ,
+}
+\cs_set_protected:Npn \_siunitx_angle_output:nnn #1#2#3 {
+  \_siunitx_angle_init:
+  \IfNoValueTF {#2}
+    {
+      \bool_set_false:N \_l_siunitx_angle_minute_zero_bool
+      \bool_set_false:N \_l_siunitx_angle_second_zero_bool
+      \_siunitx_angle_output_aux:nnn {#1} { } { }
+    }
+    {
+      \IfNoValueTF {#3}
+        { \_siunitx_error:nn { invalid-arc-format } { #1 ; #2 } }
+        { \_siunitx_angle_output_aux:nnn {#1} {#2} {#3} }
+    }
+}
+\cs_set_protected:Npn \_siunitx_angle_output_aux:nnn #1#2#3 {
+  \tl_if_empty:nTF { #1#2#3 }
+    { \_siunitx_error:n { empty-arc } }
+    {
+      \bool_if:NTF \_l_siunitx_number_parse_bool
+        { \_siunitx_angle_parse:nnn {#1} {#2} {#3} }
+        { \_siunitx_angle_direct:nnn {#1} {#2} {#3} }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_init: {
+  \bool_set_false:N \_l_siunitx_angle_degree_space_bool
+  \bool_set_false:N \_l_siunitx_angle_minute_space_bool
+  \prop_clear:N \_l_siunitx_angle_degree_prop
+  \prop_clear:N \_l_siunitx_angle_minute_prop
+  \prop_clear:N \_l_siunitx_angle_second_prop
+  \tl_clear:N \_l_siunitx_preunit_tl
+  \tl_set_eq:NN \_l_siunitx_number_unit_separator_tl
+    \_l_siunitx_angle_unit_separator_tl
+  \cs_set_eq:NN \_siunitx_number_in_parse_more:N
+    \_siunitx_number_in_parse_restricted:N
+}
+\cs_set_protected:Npn \_siunitx_angle_direct:nnn #1 {
+  \tl_if_empty:nTF {#1}
+    {
+      \bool_if:NTF \_l_siunitx_angle_degree_zero_bool
+        { \_siunitx_angle_direct_aux_i:nnn { 0 } }
+        { \_siunitx_angle_direct_aux_i:nnn { } }
+    }
+    { \_siunitx_angle_direct_aux_i:nnn {#1} }
+
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_i:nnn #1#2 {
+  \tl_if_empty:nTF {#2}
+    {
+      \bool_if:NTF \_l_siunitx_angle_minte_zero_bool
+        { \_siunitx_angle_direct_aux_ii:nnn {#1} { 0 } }
+        { \_siunitx_angle_direct_aux_ii:nnn {#1} { } }
+    }
+    { \_siunitx_angle_direct_aux_ii:nnn {#1} {#2} }
+
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_ii:nnn #1#2#3 {
+  \tl_if_empty:nTF {#3}
+    {
+      \bool_if:NTF \_l_siunitx_angle_second_zero_bool
+        { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} { 0 } }
+        { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} { } }
+    }
+    { \_siunitx_angle_direct_aux_iii:nnn {#1} {#2} {#3} }
+}
+\cs_set_protected:Npn \_siunitx_angle_direct_aux_iii:nnn #1#2#3 {
+  \tl_if_empty:nF {#1}
+    {
+      \tl_if_empty:nF {#2#3}
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool }
+    }
+  \tl_if_empty:nF {#2}
+    {
+      \tl_if_empty:nF {#3}
+        { \bool_set_true:N \_l_siunitx_angle_minute_space_bool }
+    }
+  \_siunitx_angle_print_direct:nnn {#1} {#2} {#3}
+}
+\cs_set_protected:Npn \_siunitx_angle_parse:nnn #1#2#3 {
+  \_siunitx_angle_parse_aux:nn {#1} { degree }
+  \_siunitx_angle_parse_aux:nn {#2} { minute }
+  \_siunitx_angle_parse_aux:nn {#3} { second }
+  \_siunitx_angle_check_sign:
+  \_siunitx_angle_zero_fill:
+  \prop_if_empty:NF \_l_siunitx_angle_degree_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool }
+      \prop_if_empty:NF \_l_siunitx_angle_second_prop
+        { \bool_set_true:N \_l_siunitx_angle_degree_space_bool }
+    }
+  \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_second_prop
+        { \bool_set_true:N \_l_siunitx_angle_minute_space_bool }
+    }
+  \_siunitx_angle_print:
+}
+\cs_set_protected:Npn \_siunitx_angle_parse_aux:nn #1#2 {
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \tl_if_empty:nF {#1}
+    {
+      \_siunitx_number_in_init:
+      \_siunitx_number_in_parse_aux:n {#1}
+    }
+  \prop_get:NnN \_l_siunitx_number_in_prop { mantissa-sign-deleted }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_put:NnV \_l_siunitx_number_in_prop { mantissa-sign }
+        \_l_siunitx_tmpa_tl
+    }
+  \_siunitx_number_process:
+  \prop_set_eq:cN { _l_siunitx_angle_ #2 _prop }
+    \_l_siunitx_number_in_prop
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_check_sign: {
+  \prop_if_empty:NTF \_l_siunitx_angle_degree_prop
+    {
+      \prop_if_empty:NF \_l_siunitx_angle_minute_prop
+        { \_siunitx_angle_check_sign_aux:n { second } }
+    }
+    {
+      \_siunitx_angle_check_sign_aux:n { minute }
+      \_siunitx_angle_check_sign_aux:n { second }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_check_sign_aux:n #1 {
+  \prop_if_in:cnTF { _l_siunitx_angle_ #1 _prop }
+    { mantissa-sign }
+    { \msg_error:nn { siunitx } { bad-arc-sign } }
+    {
+      \prop_if_in:cnT { _l_siunitx_angle_ #1 _prop }
+        { mantissa-sign-deleted }
+        { \msg_error:nn { siunitx } { bad-arc-sign } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_zero_fill: {
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_second_prop &&
+      \_l_siunitx_angle_second_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_second_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_second_prop { mantissa-integer }
+        { 0 }
+    }
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_minute_prop &&
+      \_l_siunitx_angle_minute_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_minute_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_minute_prop { mantissa-integer }
+        { 0 }
+      \_siunitx_angle_sign_shuffle:nn { second } { minute }
+    }
+  \bool_if:nT
+    {
+      \prop_if_empty_p:N \_l_siunitx_angle_degree_prop &&
+      \_l_siunitx_angle_degree_zero_bool
+    }
+    {
+      \prop_put:Nnn \_l_siunitx_angle_degree_prop { mantissa }
+        { true }
+      \prop_put:Nnn \_l_siunitx_angle_degree_prop { mantissa-integer }
+        { 0 }
+      \_siunitx_angle_sign_shuffle:nn { second } { degree }
+      \_siunitx_angle_sign_shuffle:nn { minute } { degree }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_sign_shuffle:nn #1#2 {
+  \_siunitx_angle_sign_shuffle_aux:nnn {#1} {#2} { }
+  \_siunitx_angle_sign_shuffle_aux:nnn {#1} {#2} { -deleted }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_sign_shuffle_aux:nnn
+  #1#2#3 {
+  \prop_get:cnN { _l_siunitx_angle_ #1 _prop } { mantissa-sign #3 }
+    \_l_siunitx_tmpa_tl
+  \prop_del:cn { _l_siunitx_angle_ #1 _prop } { mantissa-sign #3 }
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_put:cnV { _l_siunitx_angle_ #2 _prop } { mantissa-sign #3 }
+        \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print: {
+  \_siunitx_angle_print_aux:nn { degree } { \SIUnitSymbolDegree }
+  \bool_if:NT \_l_siunitx_angle_degree_space_bool
+    {
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl }
+    }
+  \_siunitx_angle_print_aux:nn { minute } { \SIUnitSymbolArcminute }
+  \bool_if:NT \_l_siunitx_angle_minute_space_bool
+    {
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl }
+    }
+  \_siunitx_angle_print_aux:nn { second } { \SIUnitSymbolArcsecond }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_aux:nn #1#2 {
+  \prop_if_empty:cF { _l_siunitx_angle_ #1 _prop }
+    {
+      \prop_set_eq:Nc \_l_siunitx_number_in_prop
+        { _l_siunitx_angle_ #1 _prop }
+      \tl_set:Nn \_l_siunitx_unit_tl {#2}
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+      \bool_if:NTF \_l_siunitx_angle_astronomy_bool
+        { \_siunitx_angle_print_astronomy: }
+        { \_siunitx_number_output_single: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy: {
+  \prop_if_in:NnTF \_l_siunitx_number_in_prop
+    { mantissa-decimal-marker }
+    { \_siunitx_angle_print_astronomy_aux: }
+    { \_siunitx_number_output_single: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_aux: {
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-integer }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+  \hbox_set:Nn \_l_siunitx_angle_marker_box
+    {
+      \_siunitx_print:nn { number }
+        { \_siunitx_ensuremath:n { { \_l_siunitx_output_decimal_tl } } }
+    }
+  \hbox_set:Nn \_l_siunitx_angle_unit_box
+    {
+      \_siunitx_print:nV { unit } \_l_siunitx_unit_tl
+      \skip_horizontal:n { -\scriptspace }
+    }
+  \_siunitx_angle_print_astronomy_aux:n { marker }
+  \_siunitx_angle_print_astronomy_aux:n { unit }
+  \hbox_set:Nn \_l_siunitx_angle_marker_box
+    {
+      \box_use:N \_l_siunitx_angle_marker_box
+      \box_use:N \_l_siunitx_angle_unit_box
+    }
+  \dim_compare:nNnTF
+    { \_l_siunitx_angle_marker_dim } > { \_l_siunitx_angle_unit_dim }
+    { \_siunitx_angle_print_astronomy_marker: }
+    { \_siunitx_angle_print_astronomy_unit: }
+  \prop_get:NnN \_l_siunitx_number_out_prop { mantissa-decimal }
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_aux:n #1 {
+  \dim_set:cn { _l_siunitx_angle_ #1 _dim  }
+    { \box_wd:c { _l_siunitx_angle_ #1 _box } }
+  \hbox_set_to_wd:cnn { _l_siunitx_angle_ #1 _box } { \c_zero_skip }
+    {
+      \tex_hss:D
+      \hbox_unpack:c { _l_siunitx_angle_ #1_box }
+      \tex_hss:D
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_marker: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_angle_marker_box
+    { \_l_siunitx_angle_marker_dim }
+    {
+      \tex_hss:D
+      \hbox_unpack_clear:N \_l_siunitx_angle_marker_box
+      \tex_hss:D
+    }
+  \box_use:N \_l_siunitx_angle_marker_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_astronomy_unit: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_angle_marker_box
+    { \_l_siunitx_angle_unit_dim }
+    {
+      \tex_hss:D
+      \hbox_unpack_clear:N \_l_siunitx_angle_marker_box
+      \tex_hss:D
+    }
+  \box_use:N \_l_siunitx_angle_marker_box
+  \skip_horizontal:N \scriptspace
+}
+\cs_set_protected:Npn \_siunitx_angle_print_direct:nnn #1#2#3 {
+  \_siunitx_angle_print_direct_aux:nn {#1} { \SIUnitSymbolDegree }
+  \bool_if:NT \_l_siunitx_angle_degree_space_bool
+    {
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl }
+    }
+  \_siunitx_angle_print_direct_aux:nn {#2} { \SIUnitSymbolArcminute }
+  \bool_if:NT \_l_siunitx_angle_minute_space_bool
+    {
+      \nobreak
+      \_siunitx_ensuremath:n { \_l_siunitx_angle_arc_separator_tl }
+    }
+  \_siunitx_angle_print_direct_aux:nn {#3} { \SIUnitSymbolArcsecond }
+}
+\cs_set_protected_nopar:Npn \_siunitx_angle_print_direct_aux:nn #1#2 {
+  \tl_if_empty:nF {#1}
+    {
+      \tl_set:Nn \_l_siunitx_unit_tl {#2}
+      \_siunitx_print:nn { number } { \_siunitx_ensuremath:n {#1} }
+      \_siunitx_unit_output_print:
+    }
+}
+\tl_new:N \_l_siunitx_declare_list_tl
+\tl_set:Nn \_l_siunitx_declare_list_tl { \of \per \raiseto \tothe }
+\cs_set_protected:Npn \_siunitx_declare_power_after:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w }
+    { \textsuperscript {#2} }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    { \_siunitx_unit_parse_power_after:n {#2} }
+}
+\cs_set_protected:Npn \_siunitx_declare_power_before:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } ##1
+    { ##1 \textsuperscript {#2} }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    { \_siunitx_unit_parse_power_before:n {#2} }
+}
+\cs_set_protected:Npn \_siunitx_declare_prefix:Nnnn #1#2#3#4 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } {#2}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    {
+      \bool_if:NTF \_l_siunitx_prefix_symbols_bool
+        { \_siunitx_unit_parse_prefix:n {#2} }
+        { \_siunitx_unit_parse_prefix:nn {#3} {#4} }
+    }
+}
+\cs_set_protected:Npn \_siunitx_declare_qualifier:Nn #1#2 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w }
+    { \text { ~ } ( #2 ) }
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    { \_siunitx_unit_parse_qualifier:n {#2} }
+}
+\cs_set_protected:Npn \_siunitx_declare_unit:Nnn #1#2#3 {
+  \tl_put_right:Nn \_l_siunitx_declare_list_tl {#1}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _literal:w } {#2}
+  \cs_set:cpn { _siunitx_ \token_to_str:N #1 _function:w }
+    {
+      \cs_if_exist:cTF
+        { _siunitx_ \_siunitx_unit_first_token:n {#2} _function:w }
+        {#2}
+        { \_siunitx_unit_parse_unit:Nn #1 {#2} }
+    }
+  \tl_if_empty:nTF {#3}
+    {
+      \cs_if_free:cF { _l_siunitx_ \token_to_str:N #1 _options_tl }
+        {
+          \cs_gundefine:c { _l_siunitx_ \token_to_str:N #1 _options_tl }
+        }
+    }
+    {
+      \cs_if_free:cT { _l_siunitx_ \token_to_str:N #1 _options_tl }
+        { \tl_new:c { _l_siunitx_ \token_to_str:N #1 _options_tl } }
+      \tl_set:cn { _l_siunitx_ \token_to_str:N #1 _options_tl } {#3}
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_first_token:n #1 {
+  \exp_after:wN \token_to_str:N \tl_head_i:w #1 \q_nil
+}
+\cs_set:cpn { _siunitx_ \token_to_str:N \per _literal:w } { / }
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \per _function:w } {
+  \bool_set_true:N \_l_siunitx_per_bool
+  \_siunitx_unit_parse_per:
+}
+\cs_set:cpn { _siunitx_ \token_to_str:N \raiseto _literal:w } #1#2 {
+  #2
+  \textsuperscript {#1}
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \raiseto _function:w }
+  #1 {
+  \_siunitx_unit_parse_power_before:n {#1}
+}
+\cs_set:cpn { _siunitx_ \token_to_str:N \tothe _literal:w } #1 {
+  \textsuperscript {#1}
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \tothe _function:w }
+  #1 {
+  \_siunitx_unit_parse_power_after:n {#1}
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \of _literal:w } #1 {
+  \text { ~ } ( #1 )
+}
+\cs_set_protected:cpn { _siunitx_ \token_to_str:N \of _function:w } #1 {
+  \_siunitx_unit_parse_qualifier:n {#1}
+}
+\keys_define:nn { siunitx } {
+  free-standing-units    .bool_set:N = \_l_siunitx_create_free_bool,
+  overwrite-functions    .bool_set:N =
+    \_l_siunitx_create_overwrite_bool,
+  space-before-unit      .bool_set:N = \_l_siunitx_create_prespace_bool,
+  unit-optional-argument .bool_set:N = \_l_siunitx_create_optional_bool,
+  use-xspace             .bool_set:N = \_l_siunitx_create_xspace_bool
+}
+\_siunitx_option_deactivate:n {
+  free-standing-units,
+  overwrite-functions,
+  space-before-unit,
+  unit-optional-argument,
+  use-xspace
+}
+\AtBeginDocument {
+  \bool_if:NTF \_l_siunitx_create_free_bool
+    { \_siunitx_unit_create_functions: }
+    { \_siunitx_unit_create_empty_functions: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_create_empty_functions: {
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_create_empty_functions_aux:N
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_unit_create_empty_functions_aux:N #1 {
+  \cs_if_free:NT #1 { \cs_set_protected_nopar:Npn #1 { \ERROR } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_create_functions: {
+  \bool_if:NT \_l_siunitx_create_overwrite_bool
+    { \tl_map_function:NN \_l_siunitx_declare_list_tl \cs_gundefine:N }
+  \bool_if:NTF \_l_siunitx_create_optional_bool
+    {
+      \tl_map_function:NN \_l_siunitx_declare_list_tl
+        \_siunitx_unit_create_with_arg:N
+    }
+    {
+      \tl_map_function:NN \_l_siunitx_declare_list_tl
+        \_siunitx_unit_create:N
+    }
+  \bool_if:NT \_l_siunitx_create_xspace_bool
+    { \RequirePackage { xspace } }
+}
+\cs_set_protected:Npn \_siunitx_unit_create:N #1 {
+  \cs_if_free:NT #1
+    {
+      \cs_set:Npx \_siunitx_tmp:w
+        {
+          \ProvideDocumentCommand \exp_not:N #1 { }
+            {
+              \bool_if:NT \_l_siunitx_create_prespace_bool
+                {
+                  \exp_not:n
+                    {
+                      \_siunitx_ensuremath:n
+                        { \_l_siunitx_number_unit_sep_tl }
+                    }
+                }
+              \exp_not:n { \_siunitx_unit_in:nn {#1} { } }
+              \bool_if:NT \_l_siunitx_create_xspace_bool
+                { \exp_not:N \xspace }
+            }
+        }
+      \_siunitx_tmp:w
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_create_with_arg:N #1 {
+  \cs_if_free:NT #1
+    {
+      \cs_set:Npx \_siunitx_tmp:w
+        {
+          \ProvideDocumentCommand \exp_not:N #1 { o }
+            {
+              \exp_not:N \IfNoValueTF {####1}
+                { \exp_not:n { \_siunitx_unit_in:nn {#1} { } } }
+                {
+                  \bool_if:NT \_l_siunitx_create_prespace_bool
+                    {
+                      \exp_not:n
+                        {
+                          \_siunitx_ensuremath:n
+                            { \_l_siunitx_number_unit_sep_tl }
+                        }
+                    }
+                  \SI {####1} { \exp_not:N #1 }
+                }
+              \bool_if:NT \_l_siunitx_create_xspace_bool
+                { \exp_not:N \xspace }
+            }
+        }
+      \_siunitx_tmp:w
+    }
+}
+\AtBeginDocument {
+  \tl_map_function:nN { \bar \color \ng \pm }
+    \_siunitx_protect_symbols:N
+}
+\cs_set_protected_nopar:Npn \_siunitx_protect_symbols:N #1 {
+  \cs_if_exist:NT #1
+    {
+      \_siunitx_cs_if_macro:NT #1
+        { \cs_set_protected_nopar:Npx #1 { \exp_not:V #1 } }
+    }
+}
+\keys_define:nn { siunitx } {
+  forbid-literal-units .bool_set:N =
+    \_l_siunitx_unit_forbid_literal_bool,
+  parse-units          .bool_set:N = \_l_siunitx_unit_parse_bool
+}
+\keys_set:nn { siunitx } {
+  forbid-literal-units = false,
+  parse-units          = true
+}
+\cs_set_protected:Npn \_siunitx_unit_in:nn #1#2 {
+  \bool_if:NTF \_l_siunitx_unit_parse_bool
+    {
+      \tl_if_empty:nF {#1}
+        {
+          \_siunitx_unit_if_literal:nTF {#1}
+            {
+              \bool_if:NTF \_l_siunitx_unit_forbid_literal_bool
+                { \msg_error:nnx { siunitx } { literal-unit } {#1} }
+                { \_siunitx_unit_format_literal:n {#1} }
+            }
+            {
+              \bool_if:NT \_l_siunitx_per_auto_bool
+                {
+                  \tl_set:Nn \_l_siunitx_per_mode_tl { symbol }
+                  \mode_if_inner:F
+                    {
+                      \mode_if_math:T
+                        {
+                          \tl_set:Nn \_l_siunitx_per_mode_tl
+                            { fraction }
+                        }
+                    }
+                }
+              \_siunitx_unit_parse:nn {#1} {#2}
+              \_siunitx_unit_format:
+            }
+      }
+  }
+  { \_siunitx_unit_format_literal:n {#1} }
+}
+\cs_generate_variant:Nn \_siunitx_unit_in:nn { Vn }
+\cs_set_protected:Npn \_siunitx_unit_if_literal:nTF #1#2#3 {
+  \group_begin:
+    \tl_map_function:NN \_l_siunitx_declare_list_tl
+      \_siunitx_unit_if_literal_aux:N
+    \cs_set_eq:NN \of \use_none:n
+    \cs_set_eq:NN \raiseto \use_none:n
+    \cs_set_eq:NN \tothe \use_none:n
+    \protected@edef \_l_siunitx_tmpa_tl {#1}
+  \exp_args:NNNV \group_end:
+  \tl_set:Nn \_l_siunitx_tmpa_tl \_l_siunitx_tmpa_tl
+  \tl_if_empty:NTF \_l_siunitx_tmpa_tl {#3} {#2}
+}
+\cs_set_protected:Npn \_siunitx_unit_if_literal_aux:N #1 {
+  \cs_set_eq:NN #1 \prg_do_nothing:
+}
+\int_new:N \_l_siunitx_unit_int
+\prop_new:N \_l_siunitx_unit_prop
+\bool_new:N \_l_siunitx_per_bool
+\keys_define:nn { siunitx } {
+  prefixes-as-symbols .bool_set:N    = \_l_siunitx_prefix_symbols_bool,
+  sticky-per          .bool_set:N    = \_l_siunitx_sticky_per_bool,
+}
+\keys_set:nn { siunitx } {
+  prefixes-as-symbols = true
+}
+\cs_set_protected:Npn \_siunitx_unit_parse:nn #1#2 {
+  \_siunitx_unit_parse_init:
+  \_siunitx_unit_parse_options:nn {#1} {#2}
+  #1
+  \cs_set_eq:NN \pm \_siunitx_pm:
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_init: {
+  \prop_clear:N \_l_siunitx_unit_prop
+  \int_zero:N \_l_siunitx_unit_int
+  \bool_set_false:N \_l_siunitx_per_bool
+  \cs_set_eq:NN \_siunitx_pm: \pm
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_parse_init_aux:N
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_init_aux:N #1 {
+  \cs_set_eq:Nc #1 { _siunitx_ \token_to_str:N #1 _function:w }
+}
+\cs_set_protected_nopar:Npn \_siunitx_pm: { }
+\cs_set_protected:Npn \_siunitx_unit_parse_options:nn #1#2 {
+  \cs_if_free:cF
+    { _l_siunitx_ \_siunitx_unit_first_token:n {#1} _options_tl }
+    {
+      \keys_set:nv { siunitx }
+        { _l_siunitx_ \_siunitx_unit_first_token:n {#1} _options_tl }
+      \keys_set:nn { siunitx } {#2}
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_power_before:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { power- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_power_after:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_prefix:n #1 {
+  \int_incr:N \_l_siunitx_unit_int
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_prefix:nn #1#2 {
+  \_siunitx_unit_parse_prefix:n {#2}
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { prefix-base- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_per: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {  per- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl { true }
+  \bool_if:NT \_l_siunitx_sticky_per_bool
+    { \cs_set_eq:NN \per \_siunitx_unit_parse_per_error: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_per_error: {
+  \msg_error:nn { siunitx } { duplicate-sticky-per }
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_qualifier:n #1 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    { \msg_error:nn { siunitx } { qualifier-before-unit } }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { qualifier- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_unit_parse_unit:Nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl
+        { symbol- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+        { \int_incr:N \_l_siunitx_unit_int }
+    }
+    { \int_incr:N \_l_siunitx_unit_int }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { unit- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#1}
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl {#2}
+  \_siunitx_unit_parse_unit_per:
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_parse_unit_per: {
+  \bool_if:NT \_l_siunitx_sticky_per_bool
+    {
+      \bool_if:NT \_l_siunitx_per_bool
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl
+            { per- \int_use:N \_l_siunitx_unit_int }
+          \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+            { true }
+        }
+    }
+}
+\tl_new:N \_l_siunitx_preunit_tl
+\tl_new:N \_l_siunitx_unit_tl
+\tl_new:N \_l_siunitx_unit_current_tl
+\tl_new:N \_l_siunitx_unit_denominator_tl
+\tl_new:N \_l_siunitx_unit_numerator_tl
+\tl_new:N \_l_siunitx_unit_saved_tl
+\int_new:N \_l_siunitx_unit_denominator_int
+\int_new:N \_l_siunitx_unit_numerator_int
+\int_new:N \_l_siunitx_unit_prefix_int
+\int_new:N \_l_siunitx_unit_prefix_base_int
+\tl_new:N \_l_siunitx_unit_prefix_current_tl
+\int_new:N \_l_siunitx_unit_prefix_gram_int
+\bool_new:N \_l_siunitx_per_auto_bool
+\bool_new:N \_l_siunitx_per_fraction_bool
+\tl_new:N \_l_siunitx_per_mode_tl
+\bool_new:N \_l_siunitx_two_parts_bool
+\tl_new:N \_l_siunitx_qualifier_mode_tl
+\keys_define:nn { siunitx } {
+  bracket-unit-denominator .bool_set:N
+    = \_l_siunitx_unit_denominator_bracket_bool,
+  inter-unit-separator .tl_set:N = \_l_siunitx_unit_separator_tl ,
+  per-mode             .choice:,
+  per-mode / fraction .code:n =
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { fraction }
+    },
+  per-mode / power      .meta:n = { per-mode = reciprocal } ,
+  per-mode / power-positive-first .meta:n =
+    { per-mode = reciprocal-positive-first } ,
+  per-mode / reciprocal .code:n =
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_false:N \_l_siunitx_per_two_parts_bool
+      \tl_clear:N \_l_siunitx_per_mode_tl
+    },
+  per-mode / reciprocal-positive-first .code:n =
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_clear:N \_l_siunitx_per_mode_tl
+    },
+  per-mode / repeated-symbol .code:n =
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_false:N \_l_siunitx_per_fraction_bool
+      \bool_set_false:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { repeat }
+    },
+  per-mode / symbol .code:n =
+    {
+      \bool_set_false:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+      \tl_set:Nn \_l_siunitx_per_mode_tl { symbol }
+    },
+  per-mode / symbol-or-fraction .code:n =
+    {
+      \bool_set_true:N \_l_siunitx_per_auto_bool
+      \bool_set_true:N \_l_siunitx_per_fraction_bool
+      \bool_set_true:N \_l_siunitx_per_two_parts_bool
+    },
+  per-symbol           .tl_set:N  = \_l_siunitx_per_symbol_tl,
+  qualifier-mode       .choice:,
+  qualifier-mode / brackets .code:n =
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { brackets } },
+  qualifier-mode / space .code:n =
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { space } },
+  qualifier-mode / subscript .code:n =
+    { \tl_set:Nn \_l_siunitx_qualifier_mode_tl { subscript } },
+}
+\keys_set:nn { siunitx } {
+  bracket-unit-denominator = true,
+  inter-unit-separator     = \,,
+  per-mode                 = reciprocal,
+  per-symbol               = /,
+  qualifier-mode           = subscript
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format: {
+  \_siunitx_unit_format_init:
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_unit_int } = { 1 }
+    {
+      \tl_if_eq:VnT \_l_siunitx_per_mode_tl { symbol }
+        {
+          \prop_if_in:NnT \_l_siunitx_unit_prop { per-1 }
+            { \tl_clear:N \_l_siunitx_number_unit_separator_tl }
+        }
+    }
+  \intexpr_while_do:nNnn
+    { \int_use:N \_l_siunitx_unit_int } > { 0 }
+    {
+      \_siunitx_unit_format_prefix:
+      \_siunitx_unit_format_symbol:
+      \_siunitx_unit_format_qualifier:
+      \_siunitx_unit_format_power:
+      \_siunitx_unit_format_add:
+      \int_decr:N \_l_siunitx_unit_int
+    }
+  \bool_if:NT \_l_siunitx_per_two_parts_bool
+    {
+      \bool_if:NTF \_l_siunitx_per_fraction_bool
+        { \_siunitx_unit_format_fraction: }
+        { \_siunitx_unit_format_sorted: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_add: {
+  \bool_if:NTF \_l_siunitx_per_two_parts_bool
+    {
+      \tl_set:Nx \_l_siunitx_tmpb_tl
+        { per- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+        {
+          \_siunitx_unit_format_add_aux:n { _denominator }
+          \int_incr:N \_l_siunitx_unit_denominator_int
+        }
+        {
+          \_siunitx_unit_format_add_aux:n { _numerator }
+          \int_incr:N \_l_siunitx_unit_numerator_int
+        }
+    }
+    { \_siunitx_unit_format_add_aux:n { } }
+  \tl_clear:N \_l_siunitx_unit_current_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_add_aux:n #1 {
+  \tl_if_empty:cF { _l_siunitx_unit #1 _tl }
+    {
+      \tl_if_eq:nVTF { repeat } \_l_siunitx_per_mode_tl
+        {
+          \tl_set:Nx \_l_siunitx_tmpa_tl
+            { per- \intexpr_eval:n { \_l_siunitx_unit_int + 1 } }
+          \prop_if_in:NVF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+            {
+              \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+                \_l_siunitx_unit_separator_tl
+            }
+        }
+        {
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+            \_l_siunitx_unit_separator_tl
+        }
+    }
+  \tl_put_left:cV { _l_siunitx_unit #1 _tl } \_l_siunitx_unit_current_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction: {
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_unit_denominator_int } > { 0 }
+    {
+      \use:c
+        { _siunitx_unit_format_fraction_ \_l_siunitx_per_mode_tl : }
+    }
+    { \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_fraction: {
+  \tl_if_empty:NT \_l_siunitx_unit_numerator_tl
+    { \tl_set:Nn \_l_siunitx_unit_numerator_tl { 1 } }
+  \tl_set:Nx \_l_siunitx_unit_numerator_tl
+    { { \exp_not:V \_l_siunitx_unit_numerator_tl } }
+  \tl_put_left:Nn \_l_siunitx_unit_numerator_tl
+    { \_siunitx_print:nn { unit } }
+  \tl_set:Nx \_l_siunitx_unit_numerator_tl
+    { { \exp_not:V \_l_siunitx_unit_numerator_tl } }
+  \tl_set:Nx \_l_siunitx_unit_denominator_tl
+    { { \exp_not:V \_l_siunitx_unit_denominator_tl } }
+  \tl_put_left:Nn \_l_siunitx_unit_denominator_tl
+    { \_siunitx_print:nn { unit } }
+  \tl_set:Nx \_l_siunitx_unit_denominator_tl
+    { { \exp_not:V \_l_siunitx_unit_denominator_tl } }
+  \tl_set:Nn \_l_siunitx_unit_tl { \_siunitx_fraction:nn }
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+  \tl_set:Nx \_l_siunitx_unit_tl
+    { \exp_not:N \ensuremath { \exp_not:V \_l_siunitx_unit_tl } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_symbol: {
+  \_siunitx_unit_format_fraction_symbol_aux:
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_unit_denominator_int } > { 1 }
+    {
+      \bool_if:NT \_l_siunitx_unit_denominator_bracket_bool
+        {
+          \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_denominator_tl
+            \_l_siunitx_bracket_open_tl
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_denominator_tl
+            \_l_siunitx_bracket_close_tl
+        }
+    }
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_tl
+    \_l_siunitx_per_symbol_tl
+  \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_fraction_symbol_aux: {
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_unit_format_fraction_symbol_aux_alt: {
+  \tl_if_empty:NT \_l_siunitx_unit_numerator_tl
+    { \tl_set:Nn \_l_siunitx_unit_numerator_tl { 1 } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_init: {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_unit_current_tl
+  \tl_clear:N \_l_siunitx_unit_denominator_tl
+  \int_zero:N \_l_siunitx_unit_prefix_gram_int
+  \tl_clear:N \_l_siunitx_unit_numerator_tl
+  \int_zero:N \_l_siunitx_unit_prefix_base_int
+  \int_zero:N \_l_siunitx_unit_prefix_int
+  \int_zero:N \_l_siunitx_unit_denominator_int
+  \int_zero:N \_l_siunitx_unit_numerator_int
+}
+\char_make_active:N \~
+\cs_set_protected:Npn \_siunitx_unit_format_literal:n #1 {
+  \int_zero:N \_l_siunitx_unit_prefix_int
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_print_literal_aux:N
+  \tl_set:Nn \_l_siunitx_unit_tl {#1}
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \exp_not:N \_siunitx_ensuremath:n
+        { \exp_not:V \_l_siunitx_unit_separator_tl }
+    }
+  \tl_replace_all_in:NnV \_l_siunitx_unit_tl { . }
+    \_l_siunitx_tmpa_tl
+  \tl_replace_all_in:NnV \_l_siunitx_unit_tl { ~ }
+    \_l_siunitx_tmpa_tl
+  \_siunitx_unit_format_literal_extras:
+}
+\cs_set_protected:Npn \_siunitx_unit_print_literal_aux:N #1 {
+  \cs_set_eq:Nc #1 { _siunitx_ \token_to_str:N #1 _literal:w }
+}
+\char_make_space:N \~
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_literal_extras: {
+  \_siunitx_unit_format_literal_extras_aux:nN { 176 }
+    \SIUnitSymbolDegree
+  \_siunitx_unit_format_literal_extras_aux:nN { 181 }
+    \SIUnitSymbolMicro
+  \_siunitx_unit_format_literal_extras_aux:nN { 197 }
+    \SIUnitSymbolAngstrom
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_unit_format_literal_extras_aux:nN #1#2 {
+  \char_set_lccode:nn { `\@ } {#1}
+  \tl_to_lowercase:n
+    {
+      \tl_replace_all_in:NnV \_l_siunitx_unit_tl { @ }
+        \_l_siunitx_unit_tl
+    }
+}
+\xetex_if_engine:F {
+    \AtBeginDocument
+      {
+        \@ifpackageloaded { inputenc }
+          {
+            \tl_set:Nn \_l_siunitx_tmpa_tl { latin1 , latin5 , latin9 }
+            \clist_if_in:NVF \_l_siunitx_tmpa_tl \inputencodingname
+              {
+                \cs_set_eq:NN \_siunitx_unit_format_literal_extras:
+                  \scan_stop:
+              }
+          }
+          {
+            \cs_set_eq:NN \_siunitx_unit_format_literal_extras:
+              \scan_stop:
+          }
+      }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl
+        { per- \int_use:N \_l_siunitx_unit_int }
+      \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+        {
+          \tl_set:Nn \_l_siunitx_tmpa_tl { 1 }
+          \_siunitx_unit_format_power_aux:
+        }
+    }
+    { \_siunitx_unit_format_power_aux: }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_aux: {
+  \tl_if_eq:nVTF { repeat } \_l_siunitx_per_mode_tl
+    { \_siunitx_unit_format_power_repeat: }
+    { \_siunitx_unit_format_power_per: }
+  \tl_if_eq:nVF { 1 } \_l_siunitx_tmpa_tl
+    {
+      \_siunitx_unit_format_power_brackets:
+      \tl_put_right:Nx \_l_siunitx_unit_current_tl
+        {
+          ^
+            {
+              \_siunitx_unit_format_power_aux:n
+                { \exp_not:V \_l_siunitx_tmpa_tl }
+            }
+        }
+    }
+}
+\cs_set_protected:Npn \_siunitx_unit_format_power_aux:n #1 {
+  \bool_if:NTF \_l_siunitx_number_math_mode_bool
+    { \_siunitx_print:nn { number } {#1} }
+    {
+      \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+      \tl_replace_all_in:Nnn \_l_siunitx_tmpa_tl { - }
+        { \text { \_c_siunitx_minus_tl } }
+    \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+   }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_brackets: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { bracket- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_current_tl
+        \_l_siunitx_bracket_open_tl
+      \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+        \_l_siunitx_bracket_close_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_per: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { per- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+    {
+      \bool_if:NF \_l_siunitx_per_fraction_bool
+        {
+          \tl_if_in:NnTF \_l_siunitx_tmpa_tl { - }
+            {
+              \cs_set:Npn \_siunitx_tmp:w ##1 - ##2 \q_stop
+                { \tl_set:Nn \_l_siunitx_tmpa_tl {##2} }
+              \exp_afer:wN \_siunitx_tmp:w \_l_siunitx_tmpa_tl \q_stop
+            }
+            { \tl_put_left:Nn \_l_siunitx_tmpa_tl { - } }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_power_repeat: {
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { per- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+    {
+      \_siunitx_tl_put_left_math:NV \_l_siunitx_unit_current_tl
+        \_l_siunitx_per_symbol_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { prefix- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVT \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    {
+      \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+        \_l_siunitx_unit_prefix_current_tl
+      \bool_if:NTF \_l_siunitx_prefix_symbols_bool
+        { \_siunitx_unit_format_prefix_symbol: }
+        { \_siunitx_unit_format_prefix_number: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_number: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { prefix-base- \int_use:N \_l_siunitx_unit_int }
+ \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+   \_l_siunitx_tmpa_tl
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_unit_prefix_base_int } = { 0 }
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_base_int
+        { \_l_siunitx_tmpa_tl }
+    }
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_unit_prefix_base_int }
+      = { \_l_siunitx_tmpa_tl }
+    { \_siunitx_unit_format_prefix_number_calc: }
+    { \msg_error:nn { siunitx } { prefix-base-mismatch } }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_number_calc: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { power- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_set:Nn \_l_siunitx_tmpa_tl { 1 } }
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { unit- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl
+    \_l_siunitx_tmpb_tl
+  \tl_if_eq:nVT { \gram } \_l_siunitx_tmpb_tl
+    {
+      \tl_set:Nx \_l_siunitx_unit_prefix_current_tl
+        { \intexpr_eval:n { \_l_siunitx_unit_prefix_current_tl  - 3 } }
+      \tl_set:Nx \_l_siunitx_tmpb_tl
+        { symbol- \int_use:N \_l_siunitx_unit_int }
+      \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpb_tl { kg }
+    }
+  \tl_set:Nx \_l_siunitx_unit_prefix_current_tl
+    {
+       \intexpr_eval:n
+         { \_l_siunitx_unit_prefix_current_tl * \_l_siunitx_tmpa_tl }
+    }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { per- \int_use:N \_l_siunitx_unit_int }
+  \prop_if_in:NVTF \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_int
+        {
+          \int_use:N \_l_siunitx_unit_prefix_int
+            - \_l_siunitx_unit_prefix_current_tl
+        }
+    }
+    {
+      \int_set:Nn \_l_siunitx_unit_prefix_int
+        {
+          \int_use:N \_l_siunitx_unit_prefix_int
+            + \_l_siunitx_unit_prefix_current_tl
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_prefix_symbol: {
+  \tl_set_eq:NN \_l_siunitx_unit_current_tl
+    \_l_siunitx_unit_prefix_current_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { qualifier- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NF \_l_siunitx_tmpa_tl
+    {
+      \use:c
+        {
+          _siunitx_unit_format_qualifier_
+          \_l_siunitx_qualifier_mode_tl :
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_brackets: {
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+    \_l_siunitx_bracket_open_tl
+  \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+  \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_current_tl
+    \_l_siunitx_bracket_close_tl
+}
+\char_make_active:N \~
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_space: {
+  \tl_put_right:Nn \_l_siunitx_unit_current_tl { \text { ~ } }
+  \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { bracket- \int_use:N \_l_siunitx_unit_int }
+  \prop_put:NVn \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl { true }
+}
+\char_make_space:N \~
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \cs_set_protected_nopar:Npn \_siunitx_unit_format_qualifier_subscript:
+    {
+      \tl_put_right:No \_l_siunitx_unit_current_tl
+        { \exp_after:wN @ \exp_after:wN { \_l_siunitx_tmpa_tl } }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_sorted: {
+  \tl_set_eq:NN \_l_siunitx_unit_tl \_l_siunitx_unit_numerator_tl
+  \tl_if_empty:NF \_l_siunitx_unit_tl
+    {
+      \tl_if_empty:NF \_l_siunitx_unit_denominator_tl
+        {
+          \_siunitx_tl_put_right_math:NV \_l_siunitx_unit_tl
+            \_l_siunitx_unit_separator_tl
+        }
+    }
+    \tl_put_right:NV \_l_siunitx_unit_tl \_l_siunitx_unit_denominator_tl
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol: {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { symbol- \int_use:N \_l_siunitx_unit_int }
+  \prop_get:NVN \_l_siunitx_unit_prop \_l_siunitx_tmpa_tl
+    \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl
+    { \_siunitx_unit_format_symbol_aux: }
+    {
+      \tl_put_right:NV \_l_siunitx_unit_current_tl \_l_siunitx_tmpa_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol_aux: {
+  \msg_error:nn { siunitx } { prefix-only }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_format_symbol_aux_alt: {
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_unit_int } = { 1 }
+    {
+      \prop_del:Nn \_l_siunitx_unit_prop { prefix-1 }
+      \prop_if_empty:NF \_l_siunitx_unit_prop
+        { \msg_error:nn { siunitx } { prefix-only } }
+    }
+    { \msg_error:nn { siunitx } { prefix-only } }
+}
+\bool_new:N \_l_siunitx_multi_brackets_bool
+\bool_new:N \_l_siunitx_multi_repeat_bool
+\bool_new:N \_l_siunitx_product_brackets_bool
+\bool_new:N \_l_siunitx_product_power_bool
+\bool_new:N \_l_siunitx_number_unit_repeat_bool
+\keys_define:nn { siunitx } {
+  allow-number-unit-breaks .bool_set:N =
+    \_l_siunitx_number_unit_breaks_bool,
+  multi-part-units          .choice:,
+  multi-part-units
+    / brackets       .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_multi_brackets_bool
+        \bool_set_false:N \_l_siunitx_multi_repeat_bool
+      },
+  multi-part-units
+    / repeat         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_multi_brackets_bool
+        \bool_set_true:N  \_l_siunitx_multi_repeat_bool
+      },
+  multi-part-units
+    / single         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_multi_brackets_bool
+        \bool_set_false:N \_l_siunitx_multi_repeat_bool
+      },
+  number-unit-separator    .tl_set:N   =
+    \_l_siunitx_number_unit_separator_tl,
+  product-units            .choice:,
+  product-units
+    / brackets       .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / brackets-power .code:n =
+      {
+        \bool_set_true:N  \_l_siunitx_product_brackets_bool
+        \bool_set_true:N  \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / power          .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_true:N  \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / repeat         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_true:N  \_l_siunitx_product_repeat_bool
+      },
+  product-units
+    / single         .code:n =
+      {
+        \bool_set_false:N \_l_siunitx_product_brackets_bool
+        \bool_set_false:N \_l_siunitx_product_power_bool
+        \bool_set_false:N \_l_siunitx_product_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  multi-part-units      = brackets,
+  number-unit-separator = \,,
+  product-units         = repeat,
+}
+\cs_set_protected:Npn \_siunitx_unit_output:nn #1#2 {
+  \cs_set_eq:NN \_siunitx_unit_format_symbol_aux:
+    \_siunitx_unit_format_symbol_aux_alt:
+  \cs_set_eq:NN \_siunitx_unit_format_fraction_symbol_aux:
+    \_siunitx_unit_format_fraction_symbol_aux_alt:
+  \_siunitx_unit_in:nn {#1} {#2}
+  \intexpr_compare:nNnF
+    { \int_use:N\_l_siunitx_unit_prefix_int } = { 0 }
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl
+        {
+          \int_use:N \_l_siunitx_unit_prefix_base_int
+          ^ { \int_use:N \_l_siunitx_unit_prefix_int }
+        }
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \_siunitx_unit_output_number_sep:
+    }
+  \_siunitx_print:nV { unit } \_l_siunitx_unit_tl
+}
+\cs_generate_variant:Nn \_siunitx_unit_output:nn { Vn }
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_number_sep: {
+  \bool_if:NTF \_l_siunitx_number_unit_breaks_bool
+    { \allowbreak } { \nobreak }
+  \_siunitx_ensuremath:n { \_l_siunitx_number_unit_separator_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_pre_print: {
+  \tl_if_empty:NF \_l_siunitx_pre_unit_tl
+    {
+      \nobreak
+      \_siunitx_print:nV { unit } \_l_siunitx_pre_unit_tl
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_unit_output_print: {
+  \intexpr_compare:nNnF
+    { \int_use:N \_l_siunitx_unit_prefix_int } = { 0 }
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl
+        {
+          \bool_if:NTF \_l_siunitx_tight_bool
+            { { \exp_not:V \_l_siunitx_exponent_product_tl } }
+            { { } \exp_not:V \_l_siunitx_exponent_product_tl { } }
+          \int_use:N \_l_siunitx_unit_prefix_base_int
+          ^ { \int_use:N \_l_siunitx_unit_prefix_int }
+        }
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+    }
+  \tl_if_empty:NF \_l_siunitx_unit_tl
+    {
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_print:nV { unit } \_l_siunitx_unit_tl
+    }
+}
+\tl_new:N \_l_siunitx_pre_unit_tl
+\int_new:N \_l_siunitx_number_product_int
+\cs_set_protected:Npn \_siunitx_combined:nnnn #1#2#3#4 {
+  \IfNoValueTF {#3}
+    { \tl_clear:N \_l_siunitx_pre_unit_tl }
+    {
+      \_siunitx_unit_in:nn {#3} {#1}
+      \cs_set_eq:NN \_l_siunitx_pre_unit_tl \_l_siunitx_unit_tl
+    }
+  \cs_set_eq:NN \_l_siunitx_brackets_bool
+    \_l_siunitx_multi_brackets_bool
+  \_siunitx_combined_unit:nnn {#2} {#4} {#1}
+  \_siunitx_combined_output:n {#2}
+}
+\cs_set_protected:Npn \_siunitx_combined_output:n #1 {
+  \bool_if:NTF \_l_siunitx_number_parse_bool
+    {
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \bool_set_false:N \_l_siunitx_number_compound_bool
+      \_siunitx_number_output_parse:n {#1}
+    }
+    {
+      \_siunitx_unit_output_pre_print:
+      \_siunitx_print:nn { number } { \_siunitx_ensuremath:n {#1} }
+      \_siunitx_unit_output_print:
+    }
+}
+\cs_set_protected:Npn \_siunitx_combined_unit:nnn #1#2#3 {
+  \bool_if:NTF \_l_siunitx_product_power_bool
+    {
+      \_siunitx_combined_product_count:n {#1}
+      \intexpr_compare:nNnTF
+        { \int_use:N \_l_siunitx_number_product_int } > { 0 }
+        {
+          \int_incr:N \_l_siunitx_number_product_int
+          \tl_set:Nn \_l_siunitx_tmpa_tl {#2}
+          \tl_set:Nx \_l_siunitx_tmpb_tl
+            { \tothe { \exp_not:V \_l_siunitx_number_product_int } }
+          \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+          \_siunitx_unit_in:Vn \_l_siunitx_tmpa_tl {#3}
+        }
+        { \_siunitx_unit_in:nn {#2} {#3} }
+    }
+    { \_siunitx_unit_in:nn {#2} {#3} }
+}
+\cs_set_protected:Npn \_siunitx_combined_product_count:n #1 {
+  \int_zero:N \_l_siunitx_number_product_int
+  \tl_set:Nn \_l_siunitx_tmpa_tl {#1}
+  \tl_map_function:NN \_l_siunitx_input_product_tl
+    \_siunitx_combined_product_count_aux:N
+}
+\cs_set_protected:Npn \_siunitx_combined_product_count_aux:N #1 {
+  \tl_if_in:NnT \_l_siunitx_tmpa_tl {#1}
+    {
+      \int_incr:N \_l_siunitx_number_product_int
+      \tl_remove_in:Nn \_l_siunitx_tmpa_tl {#1}
+      \_siunitx_combined_product_count_aux:N #1
+    }
+}
+\bool_new:N \_l_siunitx_list_brackets_bool
+\bool_new:N \_l_siunitx_list_repeat_bool
+\tl_new:N \_l_siunitx_list_current_tl
+\tl_new:N \_l_siunitx_list_tl
+\keys_define:nn { siunitx } {
+  list-final-separator .tl_set:N = \_l_siunitx_list_separator_final_tl,
+  list-separator       .tl_set:N = \_l_siunitx_list_separator_tl,
+  list-units           .choice:,
+  list-units
+    / brackets .code:n   =
+      {
+        \bool_set_true:N  \_l_siunitx_list_brackets_bool
+        \bool_set_false:N \_l_siunitx_list_repeat_bool
+      },
+  list-units
+    / repeat .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_list_brackets_bool
+        \bool_set_true:N  \_l_siunitx_list_repeat_bool
+      },
+  list-units
+    / single .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_list_brackets_bool
+        \bool_set_false:N \_l_siunitx_list_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  list-final-separator = { ~ and ~ },
+  list-separator       = { , ~ },
+  list-units           = repeat,
+}
+\cs_set_protected:Npn \_siunitx_list_numbers:n #1 {
+  \tl_clear:N \_l_siunitx_unit_tl
+  \tl_clear:N \_l_siunitx_preunit_tl
+  \_siunitx_list_numbers_aux_i:n {#1}
+}
+\cs_set_protected:Npn \_siunitx_list_numbers_aux_i:n #1 {
+  \tl_clear:N \_l_siunitx_list_tl
+  \tl_clear:N \_l_siunitx_list_current_tl
+  \tl_map_function:nN {#1} \_siunitx_list_numbers_aux_ii:n
+  \tl_put_right:NV \_l_siunitx_list_tl
+    \_l_siunitx_list_separator_final_tl
+  \tl_put_right:NV \_l_siunitx_list_tl \_l_siunitx_list_current_tl
+  \tl_use:N \_l_siunitx_list_tl
+}
+\cs_set_protected:Npn \_siunitx_list_numbers_aux_ii:n #1 {
+  \tl_if_empty:NTF \_l_siunitx_list_tl
+    { \tl_set_eq:NN \_l_siunitx_list_tl \_l_siunitx_list_current_tl }
+    {
+        \tl_put_right:NV \_l_siunitx_list_tl
+          \_l_siunitx_list_separator_tl
+        \tl_put_right:NV \_l_siunitx_list_tl \_l_siunitx_list_current_tl
+    }
+  \tl_set:Nn \_l_siunitx_list_current_tl
+    { \_siunitx_combined_output:n {#1} }
+}
+\cs_set_protected:Npn \_siunitx_list_units:nnn #1#2#3 {
+  \bool_if:NTF \_l_siunitx_list_repeat_bool
+    {
+      \_siunitx_unit_in:nn {#2} {#3}
+      \_siunitx_list_numbers_aux_i:n {#1}
+    }
+    {
+      \bool_if:NT \_l_siunitx_list_brackets_bool
+        {
+          \_siunitx_print:nn { number }
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+        }
+      \_siunitx_list_numbers:n {#1}
+      \bool_if:NT \_l_siunitx_list_brackets_bool
+        {
+          \_siunitx_print:nn { number }
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+        }
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_unit_output:nn {#2} {#3}
+    }
+}
+\bool_new:N \_l_siunitx_range_brackets_bool
+\bool_new:N \_l_siunitx_range_repeat_bool
+\keys_define:nn { siunitx } {
+  range-phrase .tl_set:N = \_l_siunitx_range_phrase_tl,
+  range-units  .choice:,
+  range-units
+    / brackets .code:n   =
+      {
+        \bool_set_true:N  \_l_siunitx_range_brackets_bool
+        \bool_set_false:N \_l_siunitx_range_repeat_bool
+      },
+  range-units
+    / repeat .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_range_brackets_bool
+        \bool_set_true:N  \_l_siunitx_range_repeat_bool
+      },
+  range-units
+    / single .code:n   =
+      {
+        \bool_set_false:N \_l_siunitx_range_brackets_bool
+        \bool_set_false:N \_l_siunitx_range_repeat_bool
+      },
+}
+\keys_set:nn { siunitx } {
+  range-phrase = { ~ to ~ },
+  range-units  = repeat,
+}
+\cs_set_protected:Npn \_siunitx_range_numbers:nn #1#2 {
+  \_siunitx_range_numbers_aux:n {#1}
+  \text { \_l_siunitx_range_phrase_tl }
+  \_siunitx_range_numbers_aux:n {#2}
+}
+\cs_set_protected:Npn \_siunitx_range_numbers_aux:n #1 {
+  \bool_if:NTF \_l_siunitx_number_parse_bool
+    {
+      \tl_clear:N \_l_siunitx_number_out_tl
+      \tl_clear:N \_l_siunitx_number_out_saved_tl
+      \bool_set_false:N \_l_siunitx_number_compound_bool
+      \_siunitx_number_output_parse:n {#1}
+      \bool_if:NT \_l_siunitx_number_compound_bool
+        { \msg_error:nnx { siunitx } { multi-part-range } {#1} }
+    }
+    {
+      \_siunitx_unit_output_pre_print:
+      \_siunitx_print:nn { number } {#1}
+      \_siunitx_unit_output_print:
+    }
+}
+\cs_set_protected:Npn \_siunitx_range_unit:nnnn #1#2#3#4 {
+  \bool_if:NTF \_l_siunitx_range_repeat_bool
+    {
+      \_siunitx_unit_in:nn {#1} {#2}
+      \_siunitx_range_numbers_aux:n {#3}
+      \text { \_l_siunitx_range_phrase_tl }
+      \_siunitx_range_numbers_aux:n {#4}
+    }
+    {
+      \bool_if:NT \_l_siunitx_range_brackets_bool
+        {
+          \_siunitx_print:nn { number }
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_open_tl } }
+        }
+      \_siunitx_range_numbers:nn {#3} {#4}
+      \bool_if:NT \_l_siunitx_range_brackets_bool
+        {
+          \_siunitx_print:nn { number }
+            { \_siunitx_ensuremath:n { \_l_siunitx_bracket_close_tl } }
+        }
+      \_siunitx_unit_output_number_sep:
+      \_siunitx_unit_output:nn {#1} {#2}
+    }
+}
+\AtBeginDocument {
+  \@ifpackageloaded { cellspace }
+      {
+        \newcolumntype { C } [1]
+          { > { \bcolumn #1 \@nil } #1 < { \ecolumn } }
+        \cs_set:Npn \_siunitx_tmp:w #1 \NC@do S #2 \q_stop
+          { \toks_set:Nn \NC@list { #1 #2 } }
+        \exp_last_unbraced:NV \_siunitx_tmp:w \NC@list \q_stop
+        \cs_gundefine:N \NC@find@S
+      }
+      { }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_rewrite_create:N #1 {
+  \tl_set:Nn \_l_siunitx_tmpa_tl { \NC@do #1 }
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \NC@list
+  \newcolumntype {#1} { }
+  \toks_set:NV \NC@list \_l_siunitx_tmpa_tl
+  \exp_args:NNc \renewcommand * { NC@rewrite@ #1 } [1] [ ]
+    {
+      \toks_put_right:Nn \@temptokena
+        {
+          > { \_siunitx_table_collect_begin:Nn #1 {##1} }
+          c
+          < { \_siunitx_table_print: }
+        }
+      \NC@find
+    }
+}
+\AtBeginDocument { \_siunitx_table_rewrite_create:N s }
+\AtBeginDocument { \_siunitx_table_rewrite_create:N S }
+\tl_new:N \_l_siunitx_table_collect_tl
+\tl_new:N \_l_siunitx_table_collect_pre_tl
+\tl_new:N \_l_siunitx_table_collect_post_tl
+\tl_new:N \_l_siunitx_number_valid_tl
+\bool_new:N \_l_siunitx_table_collect_pre_bool
+\bool_new:N \_l_siunitx_table_collect_post_bool
+\cs_set_protected:Npn \_siunitx_table_collect_begin:Nn #1#2 {
+  \keys_set:nn { siunitx } {#2}
+  \use:c { _siunitx_table_collect_begin_ #1 : }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_begin_s: {
+  \cs_set_eq:NN \_siunitx_table_collect_token:N
+    \_siunitx_table_collect_token_s:N
+  \cs_set_eq:NN \_siunitx_table_print: \_siunitx_table_print_s:
+  \_siunitx_table_collect_init_s:
+  \_siunitx_table_collect_get:
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_begin_S: {
+  \cs_set_eq:NN \_siunitx_table_collect_token:N
+    \_siunitx_table_collect_token_S:N
+  \cs_set_eq:NN \_siunitx_table_print: \_siunitx_table_print_S:
+  \_siunitx_table_collect_init_S:
+  \bool_if:NTF \_l_siunitx_number_parse_bool
+    { \_siunitx_table_collect_get: }
+    { \_siunitx_table_direct: }
+}
+\cs_set_protected:Npn \_siunitx_table_collect_braced:n #1 { }
+\cs_set_protected:Npn \_siunitx_table_collect_expand:N #1 {
+  \cs_if_eq:NNTF #1 \color
+    {
+      \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+        {
+          \tl_clear:N \_l_siunitx_number_color_tl
+          \tl_clear:N \_l_siunitx_unit_color_tl
+          \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl {#1}
+        }
+        {
+          \bool_set_true:N \_l_siunitx_table_collect_post_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1}
+        }
+    }
+    {
+      \_siunitx_cs_if_tl:NTF #1
+        {
+          \tl_use:N \_l_siunitx_table_collect_pre_tl
+          \tl_clear:N \_l_siunitx_table_collect_pre_tl
+          \cs_set_nopar:Npx \_siunitx_table_collect_next:
+            { \exp_not:N \_siunitx_table_collect_get: \exp_not:V #1 }
+        }
+        {
+          \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+            { \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl {#1} }
+            {
+              \bool_set_true:N \_l_siunitx_table_collect_post_bool
+              \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1}
+            }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_get: {
+  \cs_set_eq:NN \_siunitx_table_collect_next:
+    \_siunitx_table_collect_get:
+  \cs_set_nopar:Npn \peek_execute_branches:
+    {
+      \if_catcode:w \exp_not:N \l_peek_token \c_group_begin_token
+        \exp_after:wN \_siunitx_table_collect_braced:n
+      \else:
+        \exp_after:wN \_siunitx_table_collect_not_braced:N
+      \fi:
+    }
+  \peek_after:NN \peek_ignore_spaces_execute_branches:
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init: {
+  \tl_clear:N \_l_siunitx_table_collect_tl
+  \tl_clear:N \_l_siunitx_table_collect_pre_tl
+  \tl_clear:N \_l_siunitx_table_collect_post_tl
+  \bool_set_false:N \_l_siunitx_table_collect_post_bool
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init_s: {
+  \_siunitx_table_collect_init:
+  \bool_set_false:N \_l_siunitx_table_collect_pre_bool
+  \cs_set:Npn \_siunitx_table_collect_braced:n ##1
+    {
+      \tl_put_right:Nn \_l_siunitx_table_collect_tl { {##1} }
+      \_siunitx_table_collect_next:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_init_S: {
+  \_siunitx_number_in_init:
+  \tl_set:Nx \_l_siunitx_number_valid_tl
+    {
+      \exp_not:V \_l_siunitx_input_complex_tl
+      \exp_not:V \_l_siunitx_input_decimal_tl
+      \exp_not:V \_l_siunitx_input_digit_tl
+      \exp_not:V \_l_siunitx_input_exponent_tl
+      \exp_not:V \_l_siunitx_input_ignore_tl
+      \exp_not:V \_l_siunitx_input_uncert_close_tl
+      \exp_not:V \_l_siunitx_input_uncert_open_tl
+      \exp_not:V \_l_siunitx_input_sign_tl
+      \exp_not:V \_l_siunitx_input_symbol_tl
+    }
+  \bool_set_true:N \_l_siunitx_table_collect_pre_bool
+  \cs_set:Npn \_siunitx_table_collect_braced:n ##1
+    {
+      \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+        { \tl_put_right:Nn \_l_siunitx_table_collect_pre_tl { {##1} } }
+        {
+          \bool_set_true:N \_l_siunitx_table_collect_post_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_post_tl { {##1} }
+        }
+      \_siunitx_table_collect_next:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_next: { }
+\cs_set_protected_nopar:Npn \_siunitx_table_collect_newline: {
+  \_siunitx_table_print:
+  \cs_set_eq:NN \_siunitx_table_print: \prg_do_nothing:
+  \tabularnewline
+}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced:N #1 {
+  \token_if_eq_meaning:NNF #1 \tex_ignorespaces:D
+    {
+      \token_if_eq_meaning:NNF #1 \tex_unskip:D
+        { \_siunitx_table_collect_not_braced_aux_i:N #1 }
+    }
+  \_siunitx_table_collect_next:
+}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced_aux_i:N #1 {
+  \cs_set:Npn \_siunitx_table_collect_not_braced_aux_ii:N ##1
+    {
+      \token_if_eq_meaning:NNT #1 ##1
+        { \cs_set_eq:NN \_siunitx_table_collect_next: ##1 }
+    }
+  \tl_map_function:nN
+    { \cs:w \end \endtabular \scan_stop: \_siunitx_table_print: }
+    \_siunitx_table_collect_not_braced_aux_ii:N
+  \token_if_eq_meaning:NNT \_siunitx_table_collect_next:
+    \_siunitx_table_collect_get:
+    {
+      \token_if_eq_meaning:NNTF #1 \tabularnewline
+        {
+          \cs_set_eq:NN \_siunitx_table_collect_next:
+            \_siunitx_table_collect_newline:
+        }
+        { \_siunitx_table_collect_token:N #1 }
+    }
+}
+\cs_set_protected:Npn \_siunitx_table_collect_not_braced_aux_ii:N #1 { }
+\cs_set_protected:Npn \_siunitx_table_collect_token:N #1 { }
+\cs_set_protected:Npn \_siunitx_table_collect_token_s:N #1 {
+  \tl_put_right:Nn \_l_siunitx_table_collect_tl {#1}
+}
+\cs_set_protected:Npn \_siunitx_table_collect_token_S:N #1 {
+  \bool_if:NTF  \_l_siunitx_table_collect_post_bool
+    { \tl_put_right:Nn \_l_siunitx_table_collect_post_tl {#1} }
+    {
+      \tl_if_in:NnTF \_l_siunitx_number_valid_tl {#1}
+        {
+          \bool_set_false:N \_l_siunitx_table_collect_pre_bool
+          \tl_put_right:Nn \_l_siunitx_table_collect_tl {#1}
+        }
+        { \_siunitx_table_collect_expand:N #1 }
+    }
+}
+\skip_new:N \_c_siunitx_one_fill_skip
+\skip_set:Nn \_c_siunitx_one_fill_skip { \c_zero_skip plus 1 fill }
+\skip_new:N \_c_siunitx_table_correction_skip
+\AtBeginDocument {
+  \@ifpackageloaded { colortbl }
+    {
+      \skip_set:Nn \_c_siunitx_table_correction_skip
+        { \c_zero_skip plus -0.5 fill }
+    }
+    {
+      \skip_set:Nn \_c_siunitx_table_correction_skip
+        { \c_zero_skip }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_colortbl_correction: {
+  \skip_horizontal:n { \_c_siunitx_table_correction_skip }
+  \tex_kern:D \c_zero_skip
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_align_left:n #1 {
+  \_siunitx_table_colortbl_correction:
+  \skip_horizontal:n {#1}
+  \tex_kern:D \c_zero_skip
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_align_right:n #1 {
+  \skip_horizontal:n { \_c_siunitx_one_fill_skip - #1 }
+  \tex_kern:D \c_zero_skip
+  \_siunitx_table_colortbl_correction:
+}
+\skip_new:N \_l_siunitx_table_unit_align_skip
+\keys_define:nn { siunitx } {
+  table-unit-alignment .choice:,
+  table-unit-alignment / center .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip
+        { \c_zero_skip plus 0.5 fill }
+    },
+  table-unit-alignment / left   .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip
+        { \c_zero_skip }
+    },
+  table-unit-alignment / right  .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_unit_align_skip
+        { \c_zero_skip plus 1 fill }
+    },
+}
+\keys_set:nn { siunitx } {
+  table-unit-alignment = center
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_s: {
+  \_siunitx_table_align_left:n { \_l_siunitx_table_unit_align_skip }
+  \_siunitx_unit_output:Vn \_l_siunitx_table_collect_tl { }
+  \_siunitx_table_align_right:n { \_l_siunitx_table_unit_align_skip }
+}
+\bool_new:N \_l_siunitx_table_center_decimal_bool
+\box_new:N \_l_siunitx_table_fill_box
+\dim_new:N \_l_siunitx_table_fill_dim
+\box_new:N \_l_siunitx_table_pre_box
+\box_new:N \_l_siunitx_table_post_box
+\box_new:N \_l_siunitx_table_result_box
+\dim_new:N \_l_siunitx_table_decimal_dim
+\dim_new:N \_l_siunitx_table_exponent_dim
+\dim_new:N \_l_siunitx_table_integer_dim
+\dim_new:N \_l_siunitx_table_mantissa_dim
+\dim_new:N \_l_siunitx_table_marker_dim
+\dim_new:N \_l_siunitx_table_result_dim
+\dim_new:N \_l_siunitx_table_uncert_dim
+\dim_new:N \_l_siunitx_table_gap_dim
+\prop_new:N \_l_siunitx_table_model_prop
+\skip_new:N \_l_siunitx_table_number_align_skip
+\skip_new:N \_l_siunitx_table_text_align_skip
+\keys_define:nn { siunitx } {
+  table-align-text-post       .bool_set:N
+    = \_l_siunitx_table_align_post_bool,
+  table-number-alignment      .choice:,
+  table-number-alignment /
+    center                  .code:n     =
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip
+          { \c_zero_skip plus 0.5 fill }
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment /
+    center-decimal-marker   .code:n     =
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip
+          { \c_zero_skip plus 0.5 fill }
+        \bool_set_true:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment /
+    left                    .code:n     =
       {
-        mathsrm = mathtt,
-        textrm  = ttfamily
-      }%
-  \fi
-}
-\AtBeginDocument{\si@fam@detect@default}
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-  \if b\expandafter\@car\f@series\@nil
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-  \@ifpackageloaded{color}
-    {\let\si@fam@colourcmd\color}
-    {\let\si@fam@colourcmd\@gobble}}
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-      \expandafter\expandafter\expandafter\si@textmodetrue
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-      \let\si@mathstt\si@unitmathstt
-      \let\si@textrm\si@unittextrm
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-      \let\si@texttt\si@unittexttt
-      \ifsi@colourunits
-        \let\si@colourcmd\si@fam@colourcmd
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-      \let\si@colour\si@unitcolour
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-    \si@log@debug{Italic detection: checking italic}%
-    \si@fam@ifitext
-      {\let\si@fam@italic\relax
-       \si@log@debug{Italic detection: italic}}%
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-  \si@log@debug{Weight detection: bold weight}%
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-       {#1}}}}
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-  \protected\def\mp{\si@num@mp}}
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-  \ifx\si@num@mantsign\si@tempa
-    \ifsi@colourneg
-      \expandafter\expandafter\expandafter\si@fam@colourcmd
-    \else
-      \expandafter\expandafter\expandafter\@gobble
-    \fi
-  \else
-    \expandafter\@gobble
-  \fi
-  {\si@negcolour}%
-  \si@num@procnum{exp}%
-  \si@num@procnum{mant}%
-  \si@str@ifonlychrs{\si@num@exp}{0\si@numdecimal}
-    {\ifsi@allowzeroexp\else
-       \renewcommand*{\si@num@exp}{}%
-       \ifx\@empty\si@num@mant\@empty
-         \renewcommand*{\si@num@mant}{1}%
-       \fi
-     \fi}{}%
-  \ifx\@empty\si@num@exp\@empty\else
-    \ifsi@trapambigerr
-      \expandafter\expandafter\expandafter\si@num@ambigerrtrue
-    \fi
-  \fi
-  \protected@edef\si@num@out{%
-    \ensuremath{{\si@num@mantsign}}\si@num@mant}%
-  \renewcommand*{\si@tempa}{num}%
-  \ifsi@num@intab
-    \protected@edef\si@tab@out{%
-      \ensuremath{{\si@num@mantsign}}\si@num@predec}%
-    \protected@edef\si@num@out{\si@num@postdec}%
-    \renewcommand*{\si@tempa}{tab}%
-  \fi
-  \ifx\@empty\si@num@postdec\@empty\else
-    \renewcommand*{\si@tempa}{num}%
-  \fi
-  \ifx\@empty\si@num@err\@empty\else
-    \ifsi@seperr
-      \ifsi@num@ambigerr
-        \protected@edef\si@num@out{%
-          \ensuremath{\si@openerr}\si@num@out}%
-        \si@repeatunitsfalse
-        \expandafter\si@num@erropentrue
-      \else
-        \ifsi@trapambigerr\else
-          \ifx\@empty\si@num@exp\@empty\else
-            \protected@edef\si@num@err{%
-              \si@num@err\expandafter\@car\si@numexp\@nil
-              \si@num@expsign\si@num@exp}%
-            \ifsi@repeatunits\else
-              \renewcommand*{\si@num@exp}{}%
-              \renewcommand*{\si@num@expsign}{}%
-            \fi
-          \fi
-        \fi
-      \fi
-    \else
-      \expandafter\protected@edef\csname
-        si@\si@tempa @out\endcsname{%
-          \si@num@out\ensuremath{\si@errspace}\ensuremath
-          {\si@openerr}\si@num@err\ensuremath{\si@closeerr}}%
-      \renewcommand*{\si@num@err}{}%
-    \fi
-  \fi
-  \renewcommand*{\si@tempa}{num@out}%
-  \ifsi@num@erropen
-    \renewcommand*{\si@tempa}{num@ambig}%
-  \fi
-  \ifsi@num@intab
-    \renewcommand*{\si@tempa}{tab@expout}%
-  \fi
-  \ifx\@empty\si@num@exp\@empty
-    \ifx\@empty\si@num@mant\@empty
-      \si@log@err{Invalid number format `\si@num@arg'}
-        {Something is wrong with the number format; does it
-         contain \MessageBreak any numbers (from the list
-         `\si@numdigits')?}%
-      \renewcommand*\si@num@out{}%
-    \fi
-  \else
-    \ifx\@empty\si@num@mant\@empty\else
-      \expandafter\protected@edef\csname
-        si@\si@tempa\endcsname{%
-          \csname si@\si@tempa\endcsname\ensuremath{{}%
-          \si@expproduct{}}}%
-    \fi
-    \expandafter\protected@edef\csname
-      si@\si@tempa\endcsname{%
-        \csname si@\si@tempa\endcsname\si@expbase
-        \textsuperscript{\ensuremath{\si@num@expsign}%
-        \si@num@exp}}%
-  \fi
-  \ifsi@num@intab\else
-    \expandafter\si@num@out
-  \fi
-  \ifx\@empty\si@num@err\@empty\else
-    \expandafter\si@num@procerr
-  \fi
-  \ifsi@num@erropen
-    \expandafter\si@out@num\expandafter{%
-      \ensuremath{\si@closeerr}}%
-      \ifx\@empty\si@num@ambig\@empty\else
-        \si@out@num{\si@num@ambig}%
-        \renewcommand*{\si@num@ambig}{}%
-    \fi
-  \fi
-  \si@num@erropenfalse
-  \ifx\@empty\si@num@xpart\@empty\else
-    \expandafter\si@num@sepxpart
-  \fi}
-\def\si@num@findxpart#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numprod}
-    {\si@switchtrue\si@seperrfalse}{}%
-  \ifsi@switch
-    \protected@edef\si@num@xpart{\si@num@xpart#1}%
-  \else
-    \protected@edef\si@num@in{\si@num@in#1}%
-  \fi
-  \ifx\@empty#2\@empty\else
-    \si@num@findxpart#2\@empty
-  \fi}
-\newcommand*{\si@num@sepmantexp}[1]{%
-  \expandafter\si@num@mantexp#1\@empty\@empty}
-\def\si@num@mantexp#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numgobble}
-    {\si@log@debug{Gobbling `#1' in \si@num@arg}}
-    {\si@str@ifchrstr{#1}{\si@numexp}
-       {\ifsi@switch
-          \si@log@err{Duplicate exponent marker found}
-            {Only a single exponent character \MessageBreak
-            (from the list `\si@numexp')\MessageBreak may
-            occur in a numerical argument}%
-        \else
-          \si@log@debug{Exponent marker `#1' found in
-            `\si@num@arg'}%
-        \fi
-        \si@switchtrue}%
-       {\ifsi@switch
-          \expandafter\si@num@addexp
-        \else
-          \expandafter\si@num@addmnt
-        \fi
-        {#1}}}%
-  \ifx\@empty#2\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@sepmantexp
-  \fi
-  {#2}}
-\newcommand*{\si@num@addmnt}[1]{%
-  \si@num@addmntexp{#1}{mant}{mantissa}}
-\newcommand*{\si@num@addexp}[1]{%
-  \si@num@addmntexp{#1}{exp}{exponent}}
-\newcommand*{\si@num@addmntexp}[3]{%
-  \si@log@debug{Adding `#1' to #3 for `\si@num@arg'}%
-  \expandafter\protected@edef\csname si@num@#2\endcsname{%
-    \csname si@num@#2\endcsname#1}}
-\newcommand*{\si@num@sepsign}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@gensign
-  \fi
-  {#1}}
-\newcommand*{\si@num@gensign}[1]{%
-  \expandafter\expandafter\expandafter\si@num@findsign
-    \csname si@num@#1\endcsname\@empty\@empty
-  \ifx\@empty\si@num@sign\@empty
-    \ifx\@empty\si@num@value\@empty
-      \expandafter\expandafter\expandafter\@gobble
-    \else
-      \expandafter\expandafter\expandafter\si@num@addsign
-    \fi
-  \else
-    \expandafter\@gobble
-  \fi
-  {#1}%
-  \expandafter\let\csname si@num@#1sign\endcsname\si@num@sign
-  \expandafter\let\csname si@num@#1\endcsname\si@num@value}
-\newcommand*{\si@num@sign}{}
-\def\si@num@findsign#1#2#3\@empty{%
-  \si@num@delplusfalse
-  \si@str@ifchrstr{#1}{\si@numsign}{%
-    \si@str@ifchrstr{#2}{\si@numsign}{%
-      \if +#1%
-        \if -#2%
-          \si@log@debug{Found sign combination +- for
-            `\si@num@arg'}%
-          \renewcommand*{\si@num@sign}{{\si@pm}}%
-        \else
-          \si@log@inf{Unknown sign combination `#1#2'}%
-          \renewcommand*{\si@num@sign}{{#1#2}}%
-        \fi
-      \else
-        \if -#1%
-          \if +#2%
-            \si@log@debug{Found sign combination -+ for
-              `\si@num@arg'}%
-            \renewcommand*{\si@num@sign}{{\mp}}%
-          \else
-            \si@log@inf{Unknown sign combination `#1#2'}%
-            \renewcommand*{\si@num@sign}{{#1#2}}%
-          \fi
-        \else
-          \si@log@inf{Unknown sign combination `#1#2'}%
-          \renewcommand*{\si@num@sign}{{#1#2}}%
-        \fi
-      \fi
-      \protected@edef\si@num@value{#3}}%
-      {\si@log@debug{Found single sign character `#1' for
-         `\si@num@arg'}%
-       \renewcommand*{\si@num@sign}{{#1}}%
-       \if +#1%
-         \ifsi@retainplus\else
-           \expandafter\expandafter\expandafter\si@num@killsign
-         \fi
-       \fi
-       \protected@edef\si@num@value{#2#3}}}%
-    {\si@log@debug{No sign found for `\si@num@arg'}%
-     \renewcommand*{\si@num@sign}{}%
-     \protected@edef\si@num@value{#1#2#3}}}
-\newif\ifsi@num@delplus
-\newcommand*{\si@num@killsign}{%
-  \si@num@delplustrue
-  \renewcommand*{\si@num@sign}{}}
-\newcommand*{\si@num@addsign}[1]{%
-  \begingroup
-    \renewcommand*{\si@tempa}{#1}%
-    \renewcommand*{\si@tempb}{mant}%
-    \ifx\si@tempa\si@tempb
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup
-  {\ifsi@num@signmant
-     \expandafter\si@num@asign
-   \else
-     \expandafter\@gobble
-   \fi
-   {mantissa}}
-  {\ifsi@num@signexp
-     \expandafter\si@num@asign
-   \else
-     \expandafter\@gobble
-   \fi
-   {exponent}}}
-\newcommand*{\si@num@asign}[1]{%
-  \let\si@num@sign\si@sign
-  \si@log@debug{Adding sign \si@sign\space to #1 for
-    `\si@num@arg'}}
-\newcommand*{\si@num@procnum}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@finddigits
-  \fi
-  {#1}}
-\newcommand*{\si@num@predec}{}
-\newcommand*{\si@num@postdec}{}
-\newcommand*{\si@num@finddigits}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \expandafter\expandafter\expandafter\si@num@digits
-    \csname si@num@#1\endcsname\@empty\@empty
-  \ifx\@empty\si@num@predec\@empty
-    \ifsi@num@padlead
-      \expandafter\expandafter\expandafter\si@num@addprezero
-    \fi
-  \fi
-  \ifx\@empty\si@num@postdec\@empty
-    \ifsi@num@padtrail
-      \ifsi@switch
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter
-          \si@num@addpostzero
-      \fi
-    \fi
-  \fi
-  \si@num@unsign{#1}%
-  \ifx\@empty\si@num@predec\@empty
-  \else
-    \expandafter\si@num@nozero
-  \fi
-  \ifx\@empty\si@num@predec\@empty
-    \ifx\@empty\si@num@postdec\@empty
-      \expandafter\expandafter\expandafter\@gobble
-    \else
-      \expandafter\expandafter\expandafter\si@num@sepdigits
-    \fi
-  \else
-    \expandafter\si@num@sepdigits
-  \fi
-  {#1}}
-\def\si@num@digits#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numdecimal}
-    {\ifsi@switch
-       \si@log@err{Duplicate decimal marker in `\si@num@arg'}
-         {Only a single decimal marker (from the list
-            `\si@numdecimal')\MessageBreak may occur in a
-            numerical argument}%
-     \else
-       \si@log@debug{Found decimal marker `#1' in
-         `\si@num@arg'}%
-       \expandafter\si@switchtrue
-     \fi}
-    {\si@str@ifchrstr{#1}{\si@numsign}
-       {\si@log@err{Misplaced sign character
-          `#1' in `\si@num@arg'}
-          {Sign characters `\si@numsign' can only
-            occur\MessageBreak at the start of a number}}
-       {\ifsi@switch
-          \expandafter\si@num@post
-        \else
-          \expandafter\si@num@pre
-        \fi
-        {#1}}}%
-  \ifx\@empty#2\@empty\else
-    \si@num@digits#2\@empty\@empty
-  \fi}
-\newcommand*{\si@num@pre}[1]{%
-  \si@num@prepost{#1}{pre}{integer}}
-\newcommand*{\si@num@post}[1]{%
-  \si@num@prepost{#1}{post}{decimal}}
-\newcommand*{\si@num@prepost}[3]{%
-  \expandafter\protected@edef\csname si@num@#2dec\endcsname{%
-    \csname si@num@#2dec\endcsname#1}%
-  \si@log@debug{Adding `#1' to #3 part for `\si@num@arg'}}
-\newcommand*{\si@num@addprezero}{%
-  \si@num@addpzero{pre}{leading}}
-\newcommand*{\si@num@addpostzero}{%
-  \si@num@addpzero{post}{trailing}}
-\newcommand*{\si@num@addpzero}[2]{%
-  \si@log@debug{Adding #2 zero for `\si@num@arg'}%
-  \@namedef{si@num@#1dec}{0}}
-\newcommand*{\si@num@unsign}[1]{%
-  \expandafter\ifx\expandafter\@empty
-    \csname si@num@#1sign\endcsname\@empty
-    \expandafter\@gobble
-  \else
-    \expandafter\si@num@nosign
-  \fi
-  {#1}}
-\newcommand*{\si@num@nosign}[1]{%
-  \begingroup
-    \si@switchtrue
-    \si@str@ifonlychrs{\si@num@predec\si@num@postdec}{0}
-      {\si@switchfalse}{}%
-    \ifsi@switch
-      \aftergroup\@gobble
-    \else
-      \aftergroup\@firstofone
-    \fi
-  \endgroup
-  {\si@log@debug{Zero value: removing any sign}%
-   \ifsi@ang@sign\else
-     \@namedef{si@num@#1sign}{}%
-   \fi}}
-\newcommand*{\si@num@nozero}{%
-  \si@str@ifonlychrs{\si@num@predec}{0}
-    {\renewcommand*{\si@num@predec}{0}}{}}
-\newcommand*{\si@num@decimalhook}{}
-\newcommand*{\si@num@sepdigits}[1]{%
-  \begingroup
-    \let\si@numextra\si@numaddn
-    \protected@edef\si@tempa{\si@num@predec\si@num@postdec}%
-    \si@num@ifextra{\si@tempa}
-      {\aftergroup\@gobble}
-      {\aftergroup\@firstofone}%
-  \endgroup
-  {\renewcommand*{\si@tempb}{mant}%
-   \renewcommand*{\si@tempc}{#1}%
-   \ifx\si@tempb\si@tempc
-     \expandafter\si@num@checkerr
-   \fi}%
-  \protected@edef\si@tempa{\si@num@predec\si@num@postdec}%
-  \expandafter\si@str@ifonlychrs\expandafter{\si@tempa}
-    {0123456789}
-    {\ifx\@empty\si@num@err\@empty
-       \renewcommand*{\si@tempb}{mant}%
-       \renewcommand*{\si@tempc}{#1}%
-       \ifx\si@tempb\si@tempc
-         \expandafter\expandafter\expandafter\si@num@fixlength
-       \fi
-     \fi}{}%
-  \si@num@ifextra{\si@num@predec}{}
-    {\expandafter\si@num@int\expandafter{\si@num@predec}}%
-  \renewcommand*{\si@tempc}{}%
-  \ifx\@empty\si@num@postdec\@empty\else
-    \si@num@decimalhook
-    \renewcommand*{\si@tempc}{%
-      \ensuremath{{\si@decimalsymbol}}}%
-    \si@num@ifextra{\si@num@postdec}{}
-      {\expandafter\si@num@dec\expandafter{\si@num@postdec}}%
-  \fi
-  \expandafter\protected@edef\csname si@num@#1\endcsname
-    {\si@num@predec\si@tempc\si@num@postdec}}
-\newcommand*{\si@num@ifextra}[1]{%
-  \begingroup
-    \si@switchfalse
-    \expandafter\si@num@extra#1\@empty\@empty
-    \ifsi@switch
-      \si@log@debug{Found `extra' characters in `#1'}%
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\def\si@num@extra#1#2\@empty{%
-  \ifx\@empty#1\@empty\else
-    \si@str@ifchrstr{#1}{\si@numextra}{\si@switchtrue}{}%
-    \ifx\@empty#2\@empty\else
-      \si@num@extra#2\@empty\@empty
-    \fi
-  \fi}
-\newif\ifsi@num@ambigerr
-\newcommand*{\si@num@checkerr}{%
-  \ifx\@empty\si@num@postdec\@empty
-    \expandafter\si@num@preerr
-  \else
-    \expandafter\si@num@posterr
-  \fi}
-\newcommand*{\si@num@preerr}{%
-  \si@num@seperr{pre}%
-  \ifx\@empty\si@tempb\@empty\else
-    \expandafter\renewcommand\expandafter*\expandafter
-      \si@num@err\expandafter{\si@tempb}%
-  \fi}
-\newcommand*{\si@num@posterr}{%
-  \si@num@seperr{post}%
-  \ifx\@empty\si@tempb\@empty\else
-    \ifsi@seperr
-      \expandafter\expandafter\expandafter\si@num@psterr
-    \else
-      \let\si@num@err\si@tempb
-    \fi
-  \fi}
-\newcommand*{\si@num@psterr}{%
-    \si@num@cntdigits{\si@tempb}%
-    \si@tempcntb\si@tempcnta\relax
-    \si@num@cntdigits{\si@num@postdec}%
-    \ifnum\si@tempcnta<\si@tempcntb\relax
-      \expandafter\si@num@largeerr
-    \else
-      \expandafter\si@num@smallerr
-    \fi}
-\newcommand*{\si@num@seperr}[1]{%
-  \si@switchfalse
-  \renewcommand*{\si@tempa}{}%
-  \renewcommand*{\si@tempb}{}%
-  \expandafter\expandafter\expandafter\si@num@finderr
-    \csname si@num@#1dec\endcsname\@empty\@empty
-  \ifx\@empty\si@tempb\@empty\else
-    \expandafter\let\csname si@num@#1dec\endcsname\si@tempa
-  \fi}
-\def\si@num@finderr#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numopenerr}
-    {\ifsi@switch
-       \si@log@err{Invalid error in number}
-         {The numerical argument \si@num@arg\space has two (or
-           more)\MessageBreak error-opening characters}%
-     \else
-       \expandafter\si@switchtrue
-     \fi}
-    {\si@str@ifchrstr{#1}{\si@numcloseerr}
-       {\ifsi@switch
-          \ifx\@empty#2\@empty\else
-            \si@log@err{Invalid error in number}
-              {The numerical argument \si@num@arg\space has an
-              error-closing before the last character}%
-          \fi
-        \else
-          \si@log@err{Invalid error in number}
-           {The numerical argument \si@num@arg\space has an
-              error-closing character\MessageBreak but no
-              error-opening one}%
-        \fi}
-       {\ifsi@switch
-          \expandafter\si@num@addtmpb
-        \else
-          \expandafter\si@num@addtmpa
-        \fi
-        {#1}}}%
-  \ifx\@empty#2\@empty\else
-    \si@num@finderr#2\@empty
-  \fi}
-\newcommand*{\si@num@addtmpa}[1]{\si@num@addtmp{a}{#1}}
-\newcommand*{\si@num@addtmpb}[1]{\si@num@addtmp{b}{#1}}
-\newcommand*{\si@num@addtmp}[2]{%
-  \expandafter\protected@edef\csname si@temp#1\endcsname{%
-    \csname si@temp#1\endcsname#2}}
-\newcommand*{\si@num@cntdigits}[1]{%
-  \si@tempcnta\z@\relax
-  \expandafter\si@num@cntdgt#1\@empty\@empty}
-\def\si@num@cntdgt#1#2\@empty{%
-  \ifx\@empty#1\@empty\else
-    \advance\si@tempcnta\@ne\relax
-  \fi
-  \ifx\@empty#2\@empty\else
-    \expandafter\si@num@cntdgt#2\@empty
-  \fi}
-\newcommand*{\si@num@smallerr}{%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@serr
-  \protected@edef\si@num@err{%
-    \ifsi@num@padlead0\fi\expandafter\@car\si@numdecimal\@nil
-    \si@tempb}}
-\newcommand*{\si@num@serr}{%
-  \si@num@cntdigits{\si@tempb}%
-  \ifnum\si@tempcnta=\si@tempcntb\relax\else
-    \protected@edef\si@tempb{0\si@tempb}%
-    \expandafter\si@num@serr
-  \fi}
-\newcommand*{\si@num@largeerr}{%
-  \renewcommand*{\si@tempa}{}%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@lerr
-  \protected@edef\si@num@err{%
-    \si@tempa\expandafter\@car\si@numdecimal\@nil\si@tempb}}
-\newcommand*{\si@num@lerr}{%
-  \si@num@cntdigits{\si@tempb}%
-  \ifnum\si@tempcnta=\si@tempcntb\relax\else
-    \expandafter\si@num@movedigit\si@tempb\@empty\@empty
-    \si@num@lerr
-  \fi}
-\def\si@num@movedigit#1#2\@empty{%
-  \protected@edef\si@tempa{\si@tempa#1}%
-  \protected@edef\si@tempb{#2}}
-\newcommand*{\si@num@fixlength}{%
-  \ifsi@fixdp
-    \expandafter\si@num@fixdp
-  \else
-    \ifsi@fixsf
-      \expandafter\expandafter\expandafter\si@num@fixsf
-    \fi
-  \fi}
-\newcommand*{\si@num@fixdp}{%
-  \si@num@cntdigits{\si@num@postdec}%
-  \ifx\@empty\si@num@postdec\@empty
-    \si@tempcnta\z@\relax
-  \fi
-  \ifnum\si@tempcnta>\si@num@dp\relax
-    \expandafter\si@num@round
-  \else
-    \ifnum\si@tempcnta<\si@num@dp\relax
-      \expandafter\expandafter\expandafter\si@num@pad
-    \fi
-  \fi}
-\newcommand*{\si@num@pad}{%
-  \si@log@debug{Padding to \the\si@num@dp\space digits}%
-  \loop\ifnum\si@tempcnta<\si@num@dp\si@num@pd\repeat}
-\newcommand*{\si@num@pd}{%
-  \advance\si@tempcnta\@ne\relax
-  \protected@edef\si@num@postdec{\si@num@postdec0}}
-\newcount\si@num@rndtarget
-\newcommand*{\si@num@prernd}{}
-\newcommand*{\si@num@postrnd}{}
-\newcommand*{\si@num@round}{%
-  \si@log@debug{Rounding to \the\si@num@dp\space digits}%
-  \si@num@rndtarget\si@num@dp\relax
-  \si@num@rndstart}
-\newcommand*{\si@num@rndstart}{%
-  \si@num@reverse{\si@num@postdec}%
-  \si@num@reverse{\si@num@predec}%
-  \let\si@num@prernd\si@num@predec
-  \let\si@num@postrnd\si@num@postdec
-  \renewcommand*{\si@num@predec}{}%
-  \renewcommand*{\si@num@postdec}{}%
-  \si@switchfalse
-  \si@num@rnd}
-\newcommand*{\si@num@reverse}[1]{%
-  \renewcommand*{\si@tempa}{}%
-  \expandafter\si@num@rev#1\@empty\@empty
-  \let#1\si@tempa}
-\def\si@num@rev#1#2\@empty{%
-  \edef\si@tempa{#1\si@tempa}%
-  \ifx\@empty#2\@empty\else
-    \si@num@rev#2\@empty\@empty
-  \fi}
-\newcommand*{\si@num@rnd}{%
-  \ifx\@empty\si@num@postrnd\@empty
-    \expandafter\si@num@rndpre
-  \else
-    \expandafter\si@num@rndpost
-  \fi}
-\newcommand*{\si@num@rndpre}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@prernd\@nil}%
-  \expandafter\edef\expandafter\si@num@prernd\expandafter{%
-    \expandafter\@cdr\si@num@prernd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \ifnum\si@tempcntb=10\relax
-    \si@tempcntb\z@\relax
-    \expandafter\expandafter\expandafter\si@switchtrue
-  \fi
-  \edef\si@num@predec{\the\si@tempcntb\si@num@predec}%
-  \ifx\@empty\si@num@prernd\@empty
-    \ifsi@switch
-      \edef\si@num@predec{1\si@num@predec}%
-    \fi
-  \else
-    \expandafter\si@num@rnd
-  \fi}
-\newcommand*{\si@num@rndpost}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@postrnd\@nil}%
-  \expandafter\edef\expandafter\si@num@postrnd\expandafter{%
-    \expandafter\@cdr\si@num@postrnd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \advance\si@num@rndtarget\@ne\relax
-  \ifnum\si@tempcnta>\si@num@rndtarget\relax
-    \advance\si@num@rndtarget\m@ne\relax
-  \else
-    \advance\si@num@rndtarget\m@ne\relax
-    \ifnum\si@tempcnta>\si@num@rndtarget\relax
-      \ifnum\si@tempcntb>4\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-    \else
-      \ifnum\si@tempcntb=10\relax
-        \si@tempcntb\z@\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@postdec{\the\si@tempcntb\si@num@postdec}%
-    \fi
-  \fi
-  \advance\si@tempcnta\m@ne\relax
-  \ifnum\si@tempcnta=\m@ne\relax
-    \si@num@throw
-  \fi
-  \si@num@rnd}
-\newcommand*{\si@num@throw}{%
-  \si@num@reverse{\si@num@postdec}%
-  \edef\si@num@postdec{\expandafter\@cdr\si@num@postdec\@nil}%
-  \si@num@reverse{\si@num@postdec}}
-\newcommand*{\si@num@fixsf}{%
-  \si@num@cntdigits{\si@num@predec}%
-  \ifx\@empty\si@num@predec\@empty
-    \si@tempcnta\z@\relax
-  \fi
-  \ifnum\si@tempcnta=\@ne\relax
-    \renewcommand*{\si@tempa}{0}%
-    \ifx\si@num@predec\si@tempa
-      \ifx\@empty\si@num@postdec\@empty\else
-        \si@tempcnta\z@\relax
-        \si@switchfalse
-        \expandafter\si@num@cntpostsf\si@num@postdec
-          \@empty\@empty
-        \ifnum\si@tempcnta>\si@num@sf\relax
-          \si@log@debug{Rounding to \the\si@num@sf\space
-            figures}%
-          \si@num@rndtarget\si@num@sf\relax
-          \si@num@rndstart
-        \fi
-      \fi
-    \else
-      \si@num@cntprepost
-    \fi
-  \else
-    \ifnum\si@tempcnta<\si@num@sf\relax
-      \si@num@cntprepost
-    \else
-      \advance\si@tempcnta\m@ne\relax
-      \si@switchfalse
-      \ifnum\si@tempcnta>\si@num@sf\relax\else
-        \ifx\@empty\si@num@postdec\@empty\else
-          \edef\si@num@postdec{\expandafter\@car
-            \si@num@postdec\@nil}%
-          \ifnum\si@num@postdec>4\relax
-            \expandafter\si@switchtrue
-          \fi
-        \fi
-      \fi
-      \advance\si@tempcnta\@ne\relax
-      \renewcommand*{\si@num@postdec}{}%
-      \si@num@reverse{\si@num@predec}%
-      \let\si@num@prernd\si@num@predec
-      \renewcommand*{\si@num@predec}{}%
-      \si@num@sfpre
-      \ifsi@switch
-        \edef\si@num@predec{1\si@num@predec}%
-      \fi
-    \fi
-  \fi}
-\def\si@num@cntpostsf#1#2\@empty{%
-  \ifsi@switch
-    \advance\si@tempcnta\@ne\relax
-  \else
-    \if 0#1\relax\else
-      \si@tempcnta\@ne\relax
-      \expandafter\expandafter\expandafter\si@switchtrue
-    \fi
-  \fi
-  \ifx\@empty#2\@empty\else
-    \si@num@cntpostsf#2\@empty\@empty
-  \fi}
-\newcommand*{\si@num@cntprepost}{%
-  \si@tempcntb\si@tempcnta\relax
-  \si@num@cntdigits{\si@num@postdec}%
-  \advance\si@tempcnta\si@tempcntb\relax
-  \ifnum\si@tempcnta>\si@num@sf
-    \si@log@debug{Rounding to \the\si@num@sf\space figures}%
-    \si@num@rndtarget\si@num@sf\relax
-    \si@num@rndstart
-    \ifsi@switch
-      \si@num@throw
-    \fi
-  \fi}
-\newcommand*{\si@num@sfpre}{%
-  \expandafter\edef\expandafter\si@tempa\expandafter{%
-    \expandafter\@car\si@num@prernd\@nil}%
-  \expandafter\edef\expandafter\si@num@prernd\expandafter{%
-    \expandafter\@cdr\si@num@prernd\@nil}%
-  \si@tempcntb\si@tempa\relax
-  \ifsi@switch
-    \advance\si@tempcntb\@ne\relax
-  \fi
-  \si@switchfalse
-  \advance\si@num@sf\@ne\relax
-  \ifnum\si@tempcnta>\si@num@sf\relax
-    \advance\si@num@sf\m@ne\relax
-    \edef\si@num@predec{0\si@num@predec}%
-  \else
-    \advance\si@num@sf\m@ne\relax
-    \ifnum\si@tempcnta>\si@num@sf\relax
-      \ifnum\si@tempcntb>4\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@predec{0\si@num@predec}%
-    \else
-      \ifnum\si@tempcntb=10\relax
-        \si@tempcntb\z@\relax
-        \expandafter\expandafter\expandafter\si@switchtrue
-      \fi
-      \edef\si@num@predec{\the\si@tempcntb\si@num@predec}%
-    \fi
-  \fi
-  \advance\si@tempcnta\m@ne\relax
-  \ifx\@empty\si@num@prernd\@empty\else
-    \expandafter\si@num@sfpre
-  \fi}
-\newcommand*{\si@num@int}[1]{%
-  \renewcommand*{\si@num@predec}{}%
-  \ifsi@sepfour
-    \si@num@intfmt{}#1\@empty\@empty\@empty
-  \else
-    \si@num@iffive{#1}
-      {\si@num@intfmt{}#1\@empty\@empty\@empty}
-      {\renewcommand*{\si@num@predec}{#1}}%
-  \fi}
-\newcommand*{\si@num@iffive}[1]{%
-  \si@num@five#1\@empty\@empty\@empty\@empty\@empty\end}
-\def\si@num@five#1#2#3#4#5\end{%
-   \ifx\@empty#5\@empty
-      \expandafter\@secondoftwo
-   \else
-      \expandafter\@firstoftwo
-   \fi}
-\newcommand*{\si@num@intfmt}[4]{%
-  \ifx\@empty#2\@empty
-    \si@num@intsep#1\relax
-  \else
-    \ifx\@empty#3\@empty
-      \si@num@intsep\@empty\@empty#1#2\relax
-    \else
-      \ifx\@empty#4\@empty
-        \si@num@intsep\@empty#1#2#3\relax
-      \else
-        \si@num@fiint{#1#2#3#4}%
-      \fi
-    \fi
-  \fi}
-\def\si@num@fiint#1\fi\fi\fi{\fi\fi\fi\si@num@intfmt{#1}}
-\newcommand*{\si@num@intsep}[4]{%
-  \protected@edef\si@num@predec{\si@num@predec#1#2#3}%
-  \if\relax#4\relax\else
-    \protected@edef\si@num@predec{%
-      \si@num@predec\ensuremath{\noexpand\si@digitsep}}%
-    \expandafter\si@num@intsep\expandafter#4%
-  \fi}
-\newcommand*{\si@num@dec}[1]{%
-  \renewcommand*{\si@num@postdec}{}%
-  \ifsi@sepfour
-    \si@num@decfmt#1\@empty\@empty\@empty\@empty
-  \else
-    \si@num@iffive{#1}
-      {\si@num@decfmt#1\@empty\@empty\@empty\@empty}
-      {\protected@edef\si@num@postdec{\si@num@postdec#1}}%
-  \fi}
-\newcommand*{\si@num@decfmt}[4]{%
-  \protected@edef\si@num@postdec{\si@num@postdec#1#2#3}%
-  \ifx\@empty#4\@empty%
-  \else
-    \protected@edef\si@num@postdec{%
-      \si@num@postdec\ensuremath{\noexpand\si@digitsep}}%
-    \expandafter\si@num@decfmt\expandafter#4%
-  \fi}
-\newcommand*{\si@num@procerr}{%
-  \si@num@addunit
-  \ensuremath{\si@pm}%
-  \expandafter\si@num\expandafter{\si@num@err}}
-\newcommand*{\si@num@sepxpart}{%
-  \si@num@addunit
-  \ensuremath{{}\times{}}%
-  \expandafter\expandafter\expandafter\si@num\expandafter
-    \expandafter\expandafter{%
-      \expandafter\@cdr\si@num@xpart\@nil}}
-\newcommand*{\si@num@addunit}{%
-  \si@unt@numtrue
-  \ifx\@empty\si@unt@unitarg\@empty\else
-    \ifsi@repeatunits
-      \begingroup
-        \si@out@numfalse
-        \si@fam@setfalse
-        \si@fam@set
-        \si@unt@printunit{\si@unt@unitarg}%
-      \endgroup
-    \fi
-  \fi}
-\si@newrobustcmd*{\ang}[2][]{%
-  \begingroup
-    \sisetup{#1}%
-    \si@fam@mode
-    \si@log@debug{Processing \string\ang\space input `#2'}%
-    \@makeother{\;}%
-    \makeatletter
-    \scantokens{\si@ang@parse#2;;;\@nil}}
-\def\si@ang@parse#1;#2;#3;#4\@nil{%
-  \let\ifsi@ang@fixdp\ifsi@fixdp
-  \si@fixdpfalse
-  \si@ifmtarg{#4}
-    {\si@log@debug{Angle argument contains no
-       semi-colons:\MessageBreak decimal angle}%
-     \si@ang@dec{#1}{}{}}
-    {\si@log@debug{Angle argument contains
-       semi-colons:\MessageBreak degree-minute-second angle}%
-     \renewcommand*{\si@tempa}{#4}%
-     \renewcommand*{\si@tempb}{;;}%
-     \ifx\si@tempa\si@tempb\else
-       \ifsi@strictarc
-         \renewcommand*{\si@tempb}{;}%
-         \ifx\si@tempa\si@tempb
-           \si@log@err{Insufficient semi-colons in argument
-             of \string\ang}{The argument of
-             \string\ang\space  must contain either no
-             semi-colons or exactly two}%
-         \else
-           \si@log@err{Excess semi-colons in argument of
-             \string\ang}{The argument of \string\ang\space
-             must contain either no semi-colons or exactly
-             two}%
-         \fi
-       \fi
-     \fi
-     \si@ang@arc{#1}{#2}{#3}}}
-\newcommand*{\si@ang@dec}{%
-  \let\si@ang@fix\@gobble
-  \ifsi@ang@toarc
-    \expandafter\si@ang@dectoarc
-  \else
-    \sisetup{padangle=none,anglesep=none}\expandafter\si@ang@typeset
-  \fi}
-\newcommand*{\si@ang@arc}{%
-  \let\si@ang@fix\si@ang@arcfix
-  \ifsi@ang@todec
-    \expandafter\si@ang@arctodec
-  \else
-    \expandafter\si@ang@typeset
-  \fi}
-\newif\ifsi@ang@fixdp
-\newcommand*{\si@ang@fix}[1]{}
-\newcommand*{\si@ang@arcfix}[1]{%
-  \renewcommand*{\si@tempa}{second}%
-  \renewcommand*{\si@tempb}{#1}%
-  \ifx\si@tempa\si@tempb
-    \ifsi@ang@fixdp
-      \expandafter\expandafter\expandafter\si@fixdptrue
-    \else
-      \expandafter\expandafter\expandafter\si@fixdpfalse
-    \fi
-  \else
-    \expandafter\si@fixdpfalse
-  \fi}
-\newcommand*{\si@ang@ifnum}[1]{%
-  \begingroup
-    \renewcommand*{\si@numvalid}{0123456789,.+-}%
-    \ifx\@empty#1\@empty
-      \aftergroup\@firstoftwo
-    \else
-      \si@num@ifvalid{#1}
-        {\aftergroup\@firstoftwo}
-        {\aftergroup\@secondoftwo}%
-    \fi
-  \endgroup}
-\newcommand*{\si@ang@arctodec}[3]{%
-  \let\si@ang@fix\@gobble
-  \ifnum\si@num@dp>\thr@@\relax
-    \si@num@dp\thr@@\relax
-  \fi
-  \si@fixdptrue
-  \si@ang@ifnum{#1}
-    {\si@ang@ifnum{#2}
-      {\si@ang@ifnum{#3}
-        {\si@tempdima\z@\relax
-         \renewcommand*{\si@tempa}{+}%
-         \ifx\@empty#1\@empty\else
-           \si@tempdima #1pt\relax
-         \fi
-         \ifdim\si@tempdima<\z@\relax
-           \renewcommand*{\si@tempa}{-}%
-         \fi
-         \ifx\@empty#2\@empty\else
-           \si@tempdima\dimexpr\si@tempdima\si@tempa
-             #2pt/60\relax
-         \fi
-         \ifdim\si@tempdima<\z@\relax
-           \renewcommand*{\si@tempa}{-}%
-         \else
-         \fi
-         \ifx\@empty#3\@empty\else
-           \si@tempdima\dimexpr\si@tempdima\si@tempa
-             #3pt/3600\relax
-         \fi
-         \sisetup{numdecimal=.}%
-         \expandafter\si@ang@typeset\expandafter{%
-           \strip@pt\si@tempdima}{}{}}
-        {\si@ang@notnum{#1}{#2}{#3}}}
-      {\si@ang@notnum{#1}{#2}{#3}}}
-    {\si@ang@notnum{#1}{#2}{#3}}}
-\newcommand*{\si@ang@dectoarc}[1]{%
-  \let\si@ang@fix\si@ang@arcfix
-  \si@ang@fixdptrue
-  \ifnum\si@num@dp>\@ne\relax
-    \si@num@dp\@ne\relax
-  \fi
-  \si@ang@ifnum{#1}
-    {\si@tempdima\z@\relax
-     \ifx\@empty#1\@empty\else
-       \si@tempdima #1pt\relax
-     \fi
-     \si@ang@sepint{deg}%
-     \si@tempdima\dimexpr\si@tempdima *60\relax
-     \si@ang@sepint{min}%
-     \edef\si@tempa{\the\dimexpr\si@tempdima *60\relax}%
-     \expandafter\newcommand\expandafter*\expandafter{%
-       \expandafter\si@ang@arcsec\expandafter}\expandafter{%
-       \expandafter\si@ang@strippt\si@tempa}%
-     \si@tempdima\z@\relax
-     \edef\si@tempa{\the\si@tempdima}%
-     \expandafter\renewcommand\expandafter*\expandafter{%
-       \expandafter\si@tempa\expandafter}\expandafter{%
-       \expandafter\si@ang@strippt\si@tempa}%
-     \ifx\si@tempa\si@ang@arcsec
-       \renewcommand*{\si@ang@arcsec}{0}%
-     \fi
-     \renewcommand*{\si@tempa}{0}%
-     \ifx\si@ang@arcdeg\si@tempa
-       \si@temptoks{{}}%
-     \else
-       \si@temptoks{{\si@ang@arcdeg}}%
-     \fi
-     \ifx\si@ang@arcmin\si@tempa
-       \si@temptoks\expandafter{\the\si@temptoks{}}%
-     \else
-       \si@temptoks\expandafter{\the\si@temptoks{%
-         \si@ang@arcmin}}%
-     \fi
-     \ifx\si@ang@arcsec\si@tempa
-       \si@temptoks\expandafter{\the\si@temptoks{}}%
-     \else
-       \si@temptoks\expandafter{\the\si@temptoks{%
-         \si@ang@arcsec}}%
-     \fi
-     \expandafter\si@ang@typeset\the\si@temptoks}
-    {\si@ang@notnum{#1}{}{}}}
-\newcommand*{\si@ang@sepint}[1]{%
-  \expandafter\si@ang@sint\the\si@tempdima\@empty
-  \expandafter\let\csname si@ang@arc#1\endcsname\si@tempa}
-\def\si@ang@sint#1.#2\@empty{%
-  \renewcommand*{\si@tempa}{#1}%
-  \si@tempdima 0.#2\relax}
-\begingroup
-  \catcode`P=12
-  \catcode`T=12
-  \lowercase{
-    \renewcommand*{\si@tempa}{%
-      \def\si@ang@strippt##1PT{##1}}}
-  \expandafter\endgroup
-\si@tempa
-\newcommand*{\si@ang@notnum}[3]{%
-  \si@log@warn{Angle `#1;#2;#3' is not a pure
-    number:\MessageBreak output will be as given}%
-  \si@ang@typeset{#1}{#2}{#3}}
-\newif\ifsi@ang@sign
-\newcommand*{\si@ang@typeset}[3]{%
-  \ifsi@ang@padlarge
-    \newcommand*{\si@ang@degs}{0\si@sym@degree}%
-    \newcommand*{\si@ang@mins}{0\si@sym@minute}%
-    \newcommand*{\si@ang@secs}{0\si@sym@second}%
-  \else
-    \newcommand*{\si@ang@degs}{}%
-    \newcommand*{\si@ang@mins}{}%
-    \newcommand*{\si@ang@secs}{}%
-  \fi
-  \protected@edef\si@ang@decimalsymbol{\si@decimalsymbol}%
-  \ifsi@astroang
-    \let\si@ang@movesign\si@ang@astrosign
-  \else
-    \let\si@ang@movesign\@gobble
-  \fi
-  \newcommand*{\si@ang@secnum}{\si@ang@num{second}}%
-  \newcommand*{\si@ang@minnum}{\si@ang@num{minute}}%
-   \si@ifnotmtarg{#3}
-     {\si@log@debug{Found seconds `#3'}%
-      \si@ang@ifnum{#3}
-        {\ifdim #3 pt=\z@\relax\else
-           \si@ang@signtrue
-         \fi}{}%
-      \renewcommand*{\si@ang@secs}
-       {\si@ang@secnum{#3}\si@sym@second}%
-      \renewcommand*{\si@ang@mins}
-        {\si@ang@pad{0\si@sym@minute}}%
-      \renewcommand*{\si@ang@degs}
-        {\si@ang@pad{0\si@sym@degree}}}%
-   \si@ifnotmtarg{#2}
-     {\si@log@debug{Found minutes `#2'}%
-      \si@ang@ifnum{#2}
-        {\ifdim #2 pt=\z@\relax\else
-           \si@ang@signtrue
-         \fi}{}%
-      \renewcommand*{\si@ang@secnum}{%
-        \si@ang@signlessnum{second}}%
-      \renewcommand*{\si@ang@mins}
-       {\si@ang@minnum{#2}\si@sym@minute}%
-      \renewcommand*{\si@ang@degs}
-        {\si@ang@pad{0\si@sym@degree}}}%
-   \si@ifnotmtarg{#1}
-     {\si@log@debug{Found degrees `#1'}%
-      \renewcommand*{\si@ang@secnum}{%
-        \si@ang@signlessnum{second}}%
-      \renewcommand*{\si@ang@minnum}{%
-        \si@ang@signlessnum{minute}}%
-      \renewcommand*{\si@ang@degs}
-       {\si@ang@num{degree}{#1}%
-        \si@sym@degree}}%
-   \si@out@num
-     {\si@ang@degs\si@anglesep\si@ang@mins\si@anglesep
-        \si@ang@secs}%
-   \endgroup}
-\newcommand*{\si@ang@pad}[1]{\ifsi@ang@padsmall #1\fi}
-\newcommand*{\si@ang@num}[2]{%
-  \begingroup
-    \si@ang@fix{#1}%
-    \si@ang@movesign{#1}%
-    \si@num{#2}%
-  \endgroup}
-\newcommand*{\si@ang@signlessnum}[2]{%
-  \begingroup
-    \si@ang@fix{#1}%
-    \si@ang@movesign{#1}%
-    \sisetup{addsign=none}%
-    \si@num{#2}%
-  \endgroup}
-\newcommand*{\si@ang@killdegree}{\let\si@sym@degree\relax}
-\newcommand*{\si@ang@killminute}{\let\si@sym@minute\relax}
-\newcommand*{\si@ang@killsecond}{\let\si@sym@second\relax}
-\newcommand*{\si@ang@astrosign}[1]{%
-  \renewcommand*{\si@decimalsymbol}{%
-    \setbox\si@tempboxa=\hbox{%
-      \ensuremath{{\si@ang@decimalsymbol}}}%
-    \si@tempdima\wd\si@tempboxa\relax
-    \setbox\si@tempboxb=\hbox to\z@{%
-      \hss\unhbox\si@tempboxa\hss}%
-    \setbox\si@tempboxa=\hbox{%
-      \csname si@sym@#1\endcsname\hskip-\scriptspace}%
-    \si@tempdimb\wd\si@tempboxa\relax
-    \setbox\si@tempboxc=\hbox to\z@{%
-      \hss\unhbox\si@tempboxa\hss}%
-    \setbox\si@tempboxd=\hbox{%
-      \usebox\si@tempboxb\usebox\si@tempboxc}%
-    \ifdim\si@tempdima>\si@tempdimb\relax
-      \setbox\si@tempboxa=\hbox to\si@tempdima{%
-        \hss\unhbox\si@tempboxd\hss}%
-    \else
-      \setbox\si@tempboxa=\hbox to\si@tempdimb{%
-        \hss\unhbox\si@tempboxd\hss}%
-    \fi
-    \usebox\si@tempboxa%
-    \ifdim\si@tempdima>\si@tempdimb\relax\else
-      \hskip\scriptspace
-    \fi}%
-  \renewcommand*{\si@num@decimalhook}{\expandafter\aftergroup
-    \csname si@ang@kill#1\endcsname}}%
-\@ifpackageloaded{cellspace}
-  {\newcolumntype{C}[1]{>{\bcolumn #1\@nil}#1<{\ecolumn}}}
-  {\AtBeginDocument{
-    \@ifpackageloaded{cellspace}
-     {\newcolumntype{C}[1]{>{\bcolumn #1\@nil}#1<{\ecolumn}}%
-      \renewcommand*{\NC@rewrite@S}[1][]{%
-        \edef\si@tempa{\the\@temptokena
-        >{\noexpand\si@tab@begin@S[#1]}c%
-        <{\noexpand\si@tab@end@S}}%
-        \@temptokena\expandafter{\si@tempa}%
-        \NC@find}}
-     {}}}
-\edef\si@tempa{%
-  \noexpand\NC@do S\noexpand\NC@do s\the\NC@list}
-\newcolumntype{S}{}
-\newcolumntype{s}{}
-\NC@list\expandafter{\si@tempa}
-\newcommand*{\si@tab@corr@colortbl}{\relax}
-\AtBeginDocument{
-  \@ifpackageloaded{colortbl}{%
-    \renewcommand*{\si@tab@corr@colortbl}{%
-      \hskip\stretch{-0.5}\kern\z@
-    }
-  }{}
-}
-\renewcommand*{\NC@rewrite@S}[1][]{%
-  \edef\si@tempa{\the\@temptokena
-    >{\noexpand\si@tab@begin@S[#1]}c%
-    <{\noexpand\si@tab@end@S}}%
-  \@temptokena\expandafter{\si@tempa}%
-  \NC@find}
-\renewcommand*{\NC@rewrite@s}[1][]{%
-  \edef\si@tempa{\the\@temptokena
-    >{\noexpand\si@tab@begin@s[#1]}c%
-    <{\noexpand\si@tab@end@s}}%
-  \@temptokena\expandafter{\si@tempa}%
-  \NC@find}
-\newcommand*{\si@tab@begin@S}[1][]{%
-  \si@log@debug{Processing S column cell contents}%
-  \let\si@tab@gettok\si@tab@gettok@S
-  \si@seperrfalse
-  \renewcommand*{\si@num@sepxpart}{%
-    \si@log@err{Multiple numbers not allowed in
-       tables\MessageBreak Only the first number used}
-       \@ehb}%
-  \si@tab@begin[#1]}
-\newcommand*{\si@tab@begin@s}[1][]{%
-  \si@log@debug{Processing s column cell contents}%
-  \let\si@tab@gettok\si@tab@gettok@s
-  \si@tab@begin[#1]}
-\newtoks\si@tab@toks
-\newtoks\si@tab@pretoks
-\newtoks\si@tab@posttoks
-\newcommand*{\si@tab@begin}[1][]{%
-  \begingroup
-    \sisetup{#1}%
-    \si@tab@toks{}%
-    \si@tab@pretoks{}%
-    \si@tab@posttoks{}%
-    \si@switchfalse
-    \si@tab@gettok}
-\newcommand*{\si@tab@next}{}
-\newcommand*{\si@tab@gettok@S}[1]{%
-  \ifx\tabularnewline#1\relax
-    \let\si@tab@next\si@tab@newline@S
-  \else
-    \ifx\end#1\relax
-      \let\si@tab@next\end
-    \else
-      \ifx\si@tab@end@S#1\relax
-        \let\si@tab@next\si@tab@end@S
-      \else
-        \ifx\endtabular#1\relax
-          \let\si@tab@next\endtabular
-        \else
-          \ifx\csname#1\relax
-            \let\si@tab@next\csname
-          \else
-            \ifx\relax#1\relax
-              \let\si@tab@next\relax
-            \else
-              \let\si@tab@next\si@tab@gettok@S
-              \ifx\ignorespaces#1\relax
-                \si@tab@othertok{#1}%
-              \else
-                \ifx\unskip#1\relax
-                  \si@tab@othertok{#1}%
-                \else
-                  \si@str@ifchrstr{#1}{\si@numvalid}
-                     {\si@switchtrue
-                      \si@log@debug{Found numerical cell
-                        contents `#1'}%
-                      \si@tab@toks=\expandafter{%
-                        \the\si@tab@toks#1}}
-                     {\si@tab@ifonechar{#1}
-                       {\futurelet\si@tempa\si@tab@bracetest#1}%
-                       {\si@tab@othertok{#1}}}%
-                \fi
-              \fi
-            \fi
-          \fi
-        \fi
-      \fi
-    \fi
-  \fi
-  \si@tab@next}
-\newcommand*{\si@tab@othertok}[1]{%
-  \si@log@debug{Found other cell contents `\unexpanded{#1}'}%
-  \ifsi@switch
-    \si@log@debug{Adding to post-numeral part}%
-    \si@tab@posttoks=\expandafter{\the\si@tab@posttoks#1}%
-  \else
-    \si@log@debug{Adding to pre-numeral part}%
-    \si@tab@pretoks=\expandafter{\the\si@tab@pretoks#1}%
-  \fi}
-\newcommand*{\si@tab@ifonechar}[1]{\si@tab@onechar#1\@empty}
-\def\si@tab@onechar#1#2\@empty{%
-  \ifx\@empty#2\@empty
-    \expandafter\@firstoftwo
-  \else
-    \expandafter\@secondoftwo
-  \fi}
-\newcommand*{\si@tab@bracetest}{%
-  \ifx\si@tempa\bgroup
-    \expandafter\si@tab@othertok
-  \else
-    \expandafter\si@tab@exptest
-  \fi}
-\newcommand*{\si@tab@exptest}[1]{%
-  \edef\si@tempa{\si@tab@meaning{#1}}%
-  \ifx\si@tempa\si@tab@macro
-    \expandafter\si@tab@exptest@aux
-  \else
-    \expandafter\si@tab@othertok
-  \fi
-  {#1}%
-}
-\newcommand*{\si@tab@exptest@aux}[1]{%
-  \ifcsname\expandafter\@gobble\string#1 \endcsname
-    \si@tab@othertok{#1}%
-  \else
-    \si@log@debug{Expanding cell contents `\unexpanded{#1}'}%
-    \the\si@tab@pretoks
-    \si@tab@pretoks{}%
-    \protected@edef\si@tab@next{\noexpand\si@tab@gettok@S#1}%
-  \fi
-}
-\newcommand*{\si@tab@meaning}[1]{%
-  \expandafter\si@tab@strip\meaning#1:->:->\@empty}
-\def\si@tab@strip#1:->#2:->#3\@empty{#1}
-\newcommand*{\si@tab@macro}{}
-\edef\si@tab@macro{\si@tab@meaning{\si@tab@macro}}
-\newcommand*{\si@tab@gettok@s}[1]{%
-  \ifx\tabularnewline#1\relax
-    \let\si@tab@next\si@tab@newline@s
-  \else
-    \ifx\end#1\relax
-      \let\si@tab@next\end
-    \else
-      \ifx\si@tab@end@s#1\relax
-        \let\si@tab@next\si@tab@end@s
-      \else
-        \ifx\endtabular#1\relax
-          \let\si@tab@next\endtabular
-        \else
-          \ifx\csname#1\relax
-            \let\si@tab@next\csname
-          \else
-            \ifx\relax#1\relax
-              \let\si@tab@next\relax
-            \else
-              \let\si@tab@next\si@tab@gettok@s
-              \ifx\ignorespaces#1\relax\else
-                \ifx\unskip#1\relax\else
-                  \si@tab@toks=\expandafter{%
-                    \the\si@tab@toks#1}%
-                  \si@log@debug{Found cell contents `#1'}%
-                \fi
-              \fi
-            \fi
-          \fi
-        \fi
-      \fi
-    \fi
-  \fi
-  \si@tab@next}
-\newcommand*{\si@tab@end@S}{%
-    \ifsi@switch
-      \let\si@tab@lfill\si@tab@lfill@S
-      \let\si@tab@rfill\si@tab@rfill@S
-    \else
-      \let\si@tab@rfill\si@tab@rfill@t
-      \let\si@tab@lfill\si@tab@lfill@t
-    \fi
-    \si@tab@corr@colortbl
-    \hskip\stretch{\si@tab@lfill}\kern\z@
-    \ifsi@switch
-      \the\si@tab@pretoks
-      \si@tab@numout
-      \the\si@tab@posttoks
-    \else
-      \the\si@tab@pretoks
-    \fi
-    \hskip\stretch{\si@tab@rfill}\kern\z@
-    \si@tab@corr@colortbl
-  \endgroup}
-\newcommand*{\si@tab@end@s}{%
-    \si@tab@corr@colortbl
-    \hskip\stretch{\si@tab@lfill@s}\kern\z@
-    \ignorespaces
-    \expandafter\si\expandafter{\the\si@tab@toks}%
-    \unskip
-    \hskip\stretch{\si@tab@rfill@s}\kern\z@
-    \si@tab@corr@colortbl
-  \endgroup}
-\newcommand*{\si@tab@newline@S}{%
-  \si@tab@end@S
-  \hfil\relax
-  \let\si@tab@end\si@tab@end@S
-  \renewcommand*{\si@tab@end@S}{\let\si@tab@end@S\si@tab@end}%
-  \tabularnewline}
-\newcommand*{\si@tab@newline@s}{%
-  \si@tab@end@s
-  \hfil\relax
-  \let\si@tab@end\si@tab@end@s
-  \renewcommand*{\si@tab@end@s}{\let\si@tab@end@s\si@tab@end}%
-  \tabularnewline}
-\newcount\si@tempcnta
-\newcount\si@tempcntb
-\newcommand*{\si@tab@numout}{%
-  \si@num@intabtrue
-  \ifsi@tabparseonly\else
-    \ifsi@tab@fixed
-      \ifsi@tabautofit
-        \si@num@dp\si@tab@mantpostcnt\relax
-        \expandafter\expandafter\expandafter\expandafter
-          \expandafter\expandafter\expandafter\si@fixdptrue
-      \fi
-    \fi
-  \fi
-  \expandafter\si@num\expandafter{\the\si@tab@toks}%
-  \si@tab@format}
-\newbox\si@tab@prebox
-\newbox\si@tab@midbox
-\newbox\si@tab@postbox
-\newbox\si@tab@expbox
-\newcommand*{\si@tab@format}{%
-  \ifsi@tabparseonly
-    \expandafter\si@tab@outonly
-  \else
-    \ifsi@tab@fixed
-      \expandafter\expandafter\expandafter\si@tab@fixed
-    \else
-      \expandafter\expandafter\expandafter\si@tab@unfixed
-    \fi
-  \fi
-  \ifsi@colourvalues
-    \si@fam@colourcmd{\si@valuecolour}%
-  \fi
-  \box\si@tab@prebox\box\si@tab@midbox\box\si@tab@postbox
-    \box\si@tab@expbox}
-\newcommand*{\si@tab@outonly}{%
-  \si@log@debug{Using non-aligned S column}%
-  \setbox\si@tab@prebox=\hbox{}%
-  \setbox\si@tab@midbox=\hbox{}%
-  \setbox\si@tab@postbox=\hbox{}%
-  \setbox\si@tab@expbox=\hbox{}%
-    \protected@edef\si@tempa{%
-      \si@tab@out
-    \ifx\@empty\si@num@out\@empty\else
-      \ensuremath{{\si@decimalsymbol}}%
-    \fi
-    \si@num@out
-    \si@tab@expout}%
-  \expandafter\si@out@num\expandafter{\si@tempa}}
-\newcommand*{\si@tab@unfixed}{%
-  \si@log@debug{Using variable width S column}%
-  \ifx\@empty\si@num@out\@empty
-    \setbox\si@tab@midbox=\hbox
-      {\phantom{\ensuremath{{\si@decimalsymbol}}}}%
-  \else
-    \setbox\si@tab@midbox=\hbox
-      {\ensuremath{{\si@decimalsymbol}}}%
-  \fi
-  \protected@edef\si@num@out{\si@num@out\si@tab@expout}%
-  \setbox\si@tab@prebox=\hbox{\si@out@num{\si@tab@out}}%
-  \setbox\si@tab@postbox=\hbox{\si@out@num{\si@num@out}}%
-  \ifdim\wd\si@tab@prebox>\wd\si@tab@postbox\relax
-    \setbox\si@tab@postbox=\hbox to\wd\si@tab@prebox%
-      {\unhbox\si@tab@postbox\hfill}%
-  \else
-    \setbox\si@tab@prebox=\hbox to\wd\si@tab@postbox%
-      {\hfill\unhbox\si@tab@prebox}%
-  \fi
-  \setbox\si@tab@expbox=\hbox{}}
-\newdimen\si@tab@predim
-\newdimen\si@tab@postdim
-\newdimen\si@tab@expdim
-\newdimen\si@tempdima
-\newdimen\si@tempdimb
-\newcommand*{\si@tab@sp}{}
-\newcommand*{\si@tab@fixed}{%
-  \si@log@debug{Using fixed-width S column}%
-  \let\si@tab@sp\relax
-  \setbox\si@tab@midbox=\hbox{}%
-  \setbox\si@tab@expbox=\hbox{}%
-  \setbox\si@tempboxa=\hbox{\si@out@num{1}}%
-  \si@tempdima\wd\si@tempboxa\relax
-  \si@tab@predim\the\si@tab@mantprecnt\si@tempdima\relax
-  \si@tab@sepcorr{mantpre}{pre}%
-  \si@tab@postdim\si@tab@mantpostcnt\si@tempdima\relax
-  \setbox\si@tempboxa=\hbox{\ensuremath{{\si@decimalsymbol}}}%
-  \ifnum\si@tab@mantpostcnt=\z@\relax\else
-    \advance\si@tab@postdim\wd\si@tempboxa\relax
-  \fi
-  \si@tab@sepcorr{mantpost}{post}%
-  \setbox\si@tempboxa=\hbox{\si@out@num{^{1}}}%
-  \si@tempdima\wd\si@tempboxa\relax
-  \ifnum\si@tab@expprecnt>\z@\relax
-    \si@tab@expdim\si@tab@expprecnt\si@tempdima\relax
-    \si@tab@sepcorr{exppre}{exp}%
-  \fi
-  \let\si@tab@sp\sp
-  \ifnum\si@tab@exppostcnt>\z@\relax
-    \advance\si@tab@expdim\si@tab@exppostcnt\si@tempdima\relax
-    \setbox\si@tempboxa=\hbox{%
-      \ensuremath{^{\si@decimalsymbol}}}%
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-    \si@tab@sepcorr{exppost}{exp}%
-  \fi
-  \setbox\si@tempboxa=\hbox{\ensuremath{-}}%
-  \ifsi@tab@mantsign
-    \advance\si@tab@predim\wd\si@tempboxa\relax
-  \fi
-  \setbox\si@tempboxa=\hbox{\ensuremath{^{-}}}%
-  \ifsi@tab@expsign
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-  \fi
-  \si@tempcnta\si@tab@expprecnt\relax
-  \advance\si@tempcnta\si@tab@exppostcnt\relax
-  \ifnum\si@tempcnta>\z@\relax
-    \setbox\si@tempboxa=\hbox{\ensuremath{%
-      {}\si@expproduct{}\si@expbase}}%
-    \advance\si@tab@expdim\wd\si@tempboxa\relax
-  \fi
-  \ifsi@tabalignexp\else
-    \advance\si@tab@postdim\si@tab@expdim\relax
-  \fi
-  \setbox\si@tab@prebox=\hbox to\si@tab@predim{\hss\hfill
-    \si@out@num{\si@tab@out}}%
-  \ifx\@empty\si@num@out\@empty
-    \setbox\si@tab@postbox=\hbox to\si@tab@postdim{\hfil}%
-  \else
-    \ifsi@tabalignexp\else
-      \protected@edef\si@num@out{\si@num@out\si@tab@expout}%
-    \fi
-    \setbox\si@tab@postbox=\hbox to\si@tab@postdim
-      {\ensuremath{{\si@decimalsymbol}}\si@out@num
-        {\si@num@out}\hfil}%
-  \fi
-  \ifx\@empty\si@tab@expout\@empty
-    \ifsi@tabalignexp
-      \setbox\si@tab@expbox=\hbox to\si@tab@expdim{\hfil}%
-    \fi
-  \else
-    \ifsi@tabalignexp
-      \setbox\si@tab@expbox=\hbox to\si@tab@expdim
-        {\si@out@num{\si@tab@expout}\hfil}%
-    \fi
-  \fi}
-\newcommand*{\si@tab@sepcorr}[2]{%
-  \expandafter\si@tempcnta\expandafter\the
-    \csname si@tab@#1cnt\endcsname\relax
-  \divide\si@tempcnta\thr@@\relax
-  \ifsi@sepfour\else
-    \expandafter\ifnum\expandafter\the
-      \csname si@tab@#1cnt\endcsname=4\relax
-      \si@tempcnta\z@\relax
-    \fi
-  \fi
-  \setbox\si@tempboxa=\hbox{%
-    \ensuremath{\si@tab@sp{\si@digitsep}}}%
-  \expandafter\advance\csname si@tab@#2dim\endcsname
-    \si@tempcnta\wd\si@tempboxa}
-\si@newrobustcmd*{\SI}[2][]{%
-  \@ifnextchar[%]
-    {\si@SI[#1]{#2}}
-    {\si@SI[#1]{#2}[]}}
-\si@newrobustcmd*{\si}[2][]{\si@SI[#1]{}[]{#2}}
+        \skip_set:Nn \_l_siunitx_table_number_align_skip
+          { \c_zero_skip }
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-number-alignment /
+    right                   .code:n     =
+      {
+        \skip_set:Nn \_l_siunitx_table_number_align_skip
+          { \c_zero_skip plus 1 fill }
+        \bool_set_false:N \_l_siunitx_table_center_decimal_bool
+      },
+  table-text-alignment .choice:,
+  table-text-alignment /
+    center                  .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_text_align_skip
+        { \c_zero_skip plus 0.5 fill }
+    },
+  table-text-alignment /
+    left                    .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_text_align_skip
+        { \c_zero_skip }
+    },
+  table-text-alignment /
+    right                   .code:n =
+    {
+      \skip_set:Nn \_l_siunitx_table_text_align_skip
+        { \c_zero_skip plus 1 fill }
+    },
+  table-auto-round          .bool_set:N = \_l_siunitx_table_auto_bool,
+  table-figures-decimal     .int_set:N  = \_l_siunitx_table_decimal_int,
+  table-figures-exponent    .int_set:N  =
+    \_l_siunitx_table_exponent_int,
+  table-figures-integer     .int_set:N  = \_l_siunitx_table_integer_int,
+  table-figures-uncertainty .int_set:N  = \_l_siunitx_table_uncert_int ,
+  table-parse-only          .bool_set:N =
+    \_l_siunitx_table_parse_only_bool,
+  table-space-text-pre      .tl_set:N =
+    \_l_siunitx_table_pre_tl,
+  table-space-text-post     .tl_set:N =
+    \_l_siunitx_table_post_tl,
+  table-sign-exponent       .bool_set:N =
+    \_l_siunitx_table_sign_exponent_bool,
+  table-sign-mantissa       .bool_set:N =
+    \_l_siunitx_table_sign_mantissa_bool
+}
+\keys_set:nn { siunitx } {
+  table-align-text-post  = true,
+  table-number-alignment = center-decimal-marker,
+  table-text-alignment   = center,
+  table-figures-decimal  = 2,
+  table-figures-integer  = 3
+}
+\keys_define:nn { siunitx } {
+  table-alignment .meta:n =
+    {
+      table-number-alignment = #1,
+      table-text-alignment   = #1,
+      table-unit-alignment   = #1
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_format_convert:nn #1#2 {
+  \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NTF \_l_siunitx_tmpa_tl
+    { \int_set:cn { _l_siunitx_table_ #2 _int } { 0 } }
+    {
+      \prop_get:NnN \_l_siunitx_number_in_prop {#1} \_l_siunitx_tmpa_tl
+      \int_set:cn  { _l_siunitx_table_ #2 _int } { \_l_siunitx_tmpa_tl }
+    }
+}
+\keys_define:nn { siunitx } {
+  table-format .code:n    =
+    {
+      \_siunitx_number_in_parse:n {#1}
+      \_siunitx_table_format_convert:nn { mantissa-integer } { integer }
+      \_siunitx_table_format_convert:nn { mantissa-decimal } { decimal }
+      \_siunitx_table_format_convert:nn { mantissa-uncertainty }
+        { uncert }
+      \_siunitx_table_format_convert:nn { exponent-integer }
+        { exponent }
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { mantissa-sign }
+        { \bool_set_true:N \_l_siunitx_table_sign_mantissa_bool }
+        { \bool_set_false:N \_l_siunitx_table_sign_mantissa_bool }
+      \prop_if_in:NnTF \_l_siunitx_number_in_prop { exponent-sign }
+        { \bool_set_true:N \_l_siunitx_table_sign_mantissa_bool }
+        { \bool_set_false:N \_l_siunitx_table_sign_mantissa_bool }
+      \keys_set:nn { siunitx } { table-number-alignment = center }
+    },
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S: {
+  \bool_if:NTF \_l_siunitx_table_collect_pre_bool
+    {
+      \_siunitx_table_align_left:n { \_l_siunitx_table_text_align_skip }
+      \tl_use:N \_l_siunitx_table_collect_pre_tl
+      \_siunitx_table_align_right:n
+        { \_l_siunitx_table_text_align_skip }
+    }
+    {
+      \_siunitx_table_align_left:n
+        { \_l_siunitx_table_number_align_skip }
+      \_siunitx_table_print_S_aux:
+      \_siunitx_table_align_right:n
+        { \_l_siunitx_table_number_align_skip }
+    }
+}
 
-\newcommand*{\newunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defunit[#1]{#2}{#3}}
-    {\si@log@err{Unit \string#2 already defined!}\@eha}}
-\newcommand*{\renewunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Unit \string#2 undefined}\@ehc
-     \si@unt@defunit[#1]{#2}{#3}}
-    {\si@log@inf{Redefining unit \string#2}%
-     \si@unt@defunit[#1]{#2}{#3}}}
-\newcommand*{\provideunit}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defunit[#1]{#2}{#3}}
-    {}}
-\newcommand*{\newprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {\si@log@err{Prefix \string#2 already defined!}\@eha}}
-\newcommand*{\renewprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Prefix \string#2 undefined}\@ehc
-     \si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {\si@log@inf{Redefining prefix \string#2}%
-     \si@unt@defprefix[#1]{#2}{#3}{#4}}}
-\newcommand*{\provideprefix}[4][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defprefix[#1]{#2}{#3}{#4}}
-    {}}
-\newcommand*{\newpower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defpower[#1]{#2}{#3}}
-    {\si@log@err{Power \string#2 already defined!}\@eha}}
-\newcommand*{\renewpower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@log@err{Power \string#2 undefined}\@ehc
-     \si@unt@defpower[#1]{#2}{#3}}
-    {\si@log@inf{Redefining power \string#2}%
-     \si@unt@defpower[#1]{#2}{#3}}}
-\newcommand*{\providepower}[3][]{%
-  \si@ifdefinable{#2}
-    {\si@unt@defpower[#1]{#2}{#3}}
-    {}}
-\newcommand*{\newqualifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@unt@defqual{#1}{#2}}
-    {\si@log@err{Qualifier \string#1 already defined!}\@eha}}
-\newcommand*{\renewqualifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@log@err{Qualifier \string#1 undefined}\@ehc
-     \si@unt@defqual{#1}{#2}}
-    {\si@unt@defqual{#1}{#2}}}
-\newcommand*{\providequalifier}[2]{%
-  \si@ifdefinable{#1}
-    {\si@unt@defqual{#1}{#2}}
-    {}}
-\newif\ifsi@unt@num
-\newcommand*{\si@unt@unitarg}{}
-\newcommand*{\si@unt@SIopts}{}
-\def\si@SI[#1]#2[#3]#4{%
-  \begingroup
-    \let\fg\SIfg
-    \sisetup{#1}%
-    \renewcommand*{\si@unt@SIopts}{#1}%
-    \si@fam@mode
-    \si@unt@numfalse
-    \si@xspacefalse
-    \si@ifnotmtarg{#3}
-      {\si@log@debug{Prefix unit found}%
-       \si@unt@printunit{#3}}%
-    \si@ifnotmtarg{#4}
-      {\renewcommand*{\si@unt@unitarg}{#4}}%
-    \si@ifnotmtarg{#2}
-      {\si@log@debug{Number found in \string\SI\space
-         argument}%
-       \ifsi@repeatunits\else
-         \ifsi@trapambigerr
-           \expandafter\expandafter\expandafter
-             \si@num@ambigerrtrue
-         \fi
-       \fi
-       \num{#2}%
-       \si@unt@numtrue}%
-    \si@ifnotmtarg{#4}
-      {\si@ifmtarg{#2}
-         {\si@unt@printunit{#4}}
-         {\si@tempcnta\z@\relax
-         \ifsi@addunitpower
-           \si@unt@countx{#2}%
-         \fi
-          \ifnum\si@tempcnta>\z@\relax
-            \advance\si@tempcnta\@ne\relax
-            \edef\si@tempa{\noexpand\tothe{\si@tempcnta}}%
-            \renewcommand*{\si@tempb}{#4}%
-            \expandafter\expandafter\expandafter
-            \si@unt@printunit\expandafter\expandafter
-            \expandafter{%
-              \expandafter\si@tempb\si@tempa}%
-          \else
-            \si@unt@printunit{#4}%
-          \fi}}%
-  \endgroup}
-\newcommand*{\si@unt@countx}[1]{%
-  \si@tempcnta\z@\relax
-  \expandafter\si@unt@cntx#1\@empty\@empty}
-\def\si@unt@cntx#1#2\@empty{%
-  \si@str@ifchrstr{#1}{\si@numprod}
-    {\advance\si@tempcnta\@ne\relax}
-    {}%
-  \ifx\@empty#2\@empty\else
-    \si@unt@cntx#2\@empty\@empty
-  \fi}
-\newif\ifsi@unt@littest
-\newcommand*{\si@unt@ifliteral}[1]{%
-  \begingroup
-    \si@unt@littesttrue
-    \setbox\si@tempboxa=\hbox{\si@unt@out{#1}}%
-    \ifdim\wd\si@tempboxa>\z@\relax
-      \aftergroup\@firstoftwo
-    \else
-      \aftergroup\@secondoftwo
-    \fi
-  \endgroup}
-\newif\ifsi@unt@litout
-\newcommand*{\si@unt@printunit}[1]{%
-  \si@unt@ifliteral{#1}
-    {\ifsi@allowlitunits
-        \expandafter\si@unt@litprint
-     \else
-        \expandafter\si@unt@nolitprint
-     \fi
-     {#1}}
-    {\si@log@debug{Macro unit found:\MessageBreak
-       processing to format output}%
-     \si@unt@init
-     \advance\si@unt@depthcnt\@ne\relax
-     #1%
-     \si@unt@final}}
-\newcommand*{\si@unt@litprint}[1]{%
-  \si@log@debug{%
-    Literal items found in unit argument:\MessageBreak outputting
-    without further processing}%
-  \si@unt@litouttrue
-  \si@unt@addvaluesep
-  \si@unt@out{#1}%
-}
-\newcommand*{\si@unt@nolitprint}[1]{%
-  \si@log@err{Literal units disabled}{%
-    You can the literal input `#1' for a unit\MessageBreak
-    but the allowliteralunits option is off.
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_aux: {
+  \bool_if:NTF \_l_siunitx_table_parse_only_bool
+    {
+      \tl_use:N \_l_siunitx_table_collect_pre_tl
+      \_siunitx_number_output:V \_l_siunitx_table_collect_tl
+      \tl_use:N \_l_siunitx_table_collect_post_tl
+    }
+    {
+      \bool_if:NTF \_l_siunitx_table_center_decimal_bool
+        { \_siunitx_table_print_S_centered: }
+        { \_siunitx_table_print_S_reserved: }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_parse: {
+  \bool_set_false:N \_l_siunitx_error_bool
+  \_siunitx_number_in_parse:V \_l_siunitx_table_collect_tl
+  \bool_if:NF \_l_siunitx_error_bool
+    {
+      \_siunitx_number_process:
+      \_siunitx_number_format:
+      \_siunitx_number_output_color:
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered: {
+  \_siunitx_table_print_S_centered_ends:
+  \dim_compare:nNnTF
+    { \box_wd:N \_l_siunitx_table_pre_box } = { \c_zero_skip }
+    { \tl_use:N \_l_siunitx_table_collect_pre_tl }
+    { \box_use:N \_l_siunitx_table_pre_box }
+  \_siunitx_table_print_S_parse:
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop
+    { integer } { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop
+    { marker }  { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_number_out_prop
+    { result } { }
+  \box_set_eq:NN \_l_siunitx_table_result_box \_l_siunitx_tmp_box
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_result_dim - \_l_siunitx_table_integer_dim }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop
+    { mantissa-decimal-marker }
+    {
+      \dim_set:Nn \_l_siunitx_table_fill_dim
+        { \_l_siunitx_table_fill_dim - \_l_siunitx_table_marker_dim }
+    }
+  \dim_compare:nNnTF
+    { \_l_siunitx_table_integer_dim } > { \_l_siunitx_table_fill_dim }
+    { \_siunitx_table_print_S_centered_integer: }
+    { \_siunitx_table_print_S_centered_decimal: }
+  \bool_if:NTF \_l_siunitx_table_align_post_bool
+    { \box_use:N \_l_siunitx_table_post_box }
+    {
+      \dim_set:Nn \_l_siunitx_table_fill_dim
+        { - \dim_use:N \_l_siunitx_table_fill_dim }
+      \skip_horizontal:N \_l_siunitx_table_fill_dim
+      \box_use:N \_l_siunitx_table_post_box
+      \box_use:N \_l_siunitx_table_fill_box
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_ends: {
+  \hbox_set:Nn \_l_siunitx_table_pre_box
+    { { \tl_use:N \_l_siunitx_table_collect_pre_tl } }
+  \hbox_set:Nn \_l_siunitx_table_post_box
+    { \tl_use:N \_l_siunitx_table_collect_post_tl }
+  \dim_compare:nNnTF
+    { \box_wd:N \_l_siunitx_table_pre_box  } >
+    { \box_wd:N \_l_siunitx_table_post_box }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_table_pre_box }
+        {
+          \hbox_unpack_clear:N \_l_siunitx_table_post_box
+          \tex_hfil:D
+        }
+    }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+        { \box_wd:N \_l_siunitx_table_post_box }
+        {
+          \tex_hfil:D
+          \hbox_unpack_clear:N \_l_siunitx_table_pre_box
+        }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_integer: {
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_integer_dim - \_l_siunitx_table_fill_dim }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+    { \_l_siunitx_table_fill_dim } { \tex_hfil:D }
+  \box_use:N \_l_siunitx_table_result_box
+  \box_use:N \_l_siunitx_table_fill_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_centered_decimal: {
+  \dim_set:Nn \_l_siunitx_table_fill_dim
+    { \_l_siunitx_table_fill_dim - \_l_siunitx_table_integer_dim }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+    { \_l_siunitx_table_fill_dim } { \tex_hfil:D }
+  \box_use:N \_l_siunitx_table_fill_box
+  \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved: {
+  \dim_zero:N \_l_siunitx_table_gap_dim
+  \_siunitx_table_print_S_reserved_ends:
+  \dim_compare:nNnTF
+    { \box_wd:N \_l_siunitx_table_pre_box } = { \c_zero_skip }
+    { \tl_use:N \_l_siunitx_table_collect_pre_tl }
+    { \box_use:N \_l_siunitx_table_pre_box }
+  \_siunitx_table_print_S_model_create:
+  \bool_if:NT \_l_siunitx_table_auto_bool
+    {
+      \int_set:Nn \_l_siunitx_process_precision_int
+        { \_l_siunitx_table_decimal_int }
+      \tl_set:Nn \_l_siunitx_round_tl { places }
+    }
+  \_siunitx_table_print_S_parse:
+  \intexpr_compare:nNnTF
+    {
+      \int_use:N \_l_siunitx_table_integer_int
+        + \int_use:N \_l_siunitx_table_decimal_int
+    }
+      > { 0 }
+    { \_siunitx_table_print_S_reserved_mantissa: }
+    {
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { mantissa-result }
+        {
+          \msg_error:nnx { siunitx } { table-partial-number }
+            { a~mantissa }
+        }
+    }
+  \prop_if_in:NnT \_l_siunitx_number_out_prop { complex-result }
+    {
+      \msg_error:nnx { siunitx } { table-partial-number }
+        { a~complex }
+    }
+  \intexpr_compare:nNnTF
+    { \int_use:N \_l_siunitx_table_exponent_int } > { 0 }
+    { \_siunitx_table_print_S_reserved_exponent: }
+    {
+      \prop_if_in:NnT \_l_siunitx_number_out_prop { exponent-result }
+        {
+          \msg_error:nnx { siunitx } { table-partial-number }
+            { an~exponent }
+        }
+    }
+  \bool_if:NTF \_l_siunitx_table_align_post_bool
+    { \box_use:N \_l_siunitx_table_post_box }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+        { \dim_use:N \_l_siunitx_table_gap_dim }
+        { \tex_hfil:D }
+      \dim_set:Nn \_l_siunitx_table_gap_dim
+        { - \dim_use:N \_l_siunitx_table_gap_dim }
+      \skip_horizontal:N \_l_siunitx_table_gap_dim
+      \box_use:N \_l_siunitx_table_post_box
+      \box_use:N \_l_siunitx_table_fill_box
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_ends: {
+  \hbox_set:Nn \_l_siunitx_tmp_box { \_l_siunitx_table_pre_tl }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    {
+      \tex_hfil:D
+      { \tl_use:N \_l_siunitx_table_collect_pre_tl }
+    }
+  \hbox_set:Nn \_l_siunitx_tmp_box { \_l_siunitx_table_post_tl }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    {
+      \tl_use:N \_l_siunitx_table_collect_post_tl
+      \tex_hfil:D
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_model_create: {
+  \prop_clear:N \_l_siunitx_number_in_prop
+  \_siunitx_table_print_S_model_aux:nn { integer } { mantissa-integer }
+  \_siunitx_table_print_S_model_aux:nn { decimal } { mantissa-decimal }
+  \_siunitx_table_print_S_model_aux:nn { uncert }
+    { mantissa-uncertainty }
+  \_siunitx_table_print_S_model_aux:nn { exponent } { exponent-integer }
+  \intexpr_compare:nNnF
+    {
+      \int_use:N \_l_siunitx_table_integer_int
+        + \int_use:N \_l_siunitx_table_decimal_int
+    }
+      = { 0 }
+    {
+      \prop_put:Nnn \_l_siunitx_number_in_prop { mantissa }
+        { true }
+    }
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_table_decimal_int } > { 0 }
+    {
+      \prop_put:NnV \_l_siunitx_number_in_prop
+        { mantissa-decimal-marker }
+        \_l_siunitx_output_decimal_tl
+    }
+  \bool_if:NT \_l_siunitx_table_sign_mantissa_bool
+    { \prop_put:Nnn \_l_siunitx_number_in_prop { mantissa-sign } { - } }
+  \intexpr_compare:nNnT
+    { \int_use:N \_l_siunitx_table_exponent_int } > { 0 }
+    {
+      \bool_if:NT \_l_siunitx_table_sign_exponent_bool
+        {
+          \prop_put:Nnn \_l_siunitx_number_in_prop { exponent-sign }
+            { - }
+        }
+    }
+  \_siunitx_number_process:
+  \_siunitx_number_format:
+  \prop_set_eq:NN \_l_siunitx_table_model_prop
+    \_l_siunitx_number_out_prop
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_model_aux:nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \prg_replicate:nn { \int_use:c { _l_siunitx_table_ #1 _int } }
+        { 8 }
+    }
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \prop_put:NnV \_l_siunitx_number_in_prop {#2} \_l_siunitx_tmpa_tl
+      \prop_put:Nnn  \_l_siunitx_number_in_prop {#1} { true }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_mantissa: {
+  \_siunitx_table_print_S_reserved_mantissa_aux:n { mantissa }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { mantissa } { }
+  \_siunitx_table_print_S_get_mantissa:Nn
+    \_l_siunitx_number_out_prop { }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \_l_siunitx_table_mantissa_dim }
+    {
+      \box_use:N \_l_siunitx_table_fill_box
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box
+  \_siunitx_table_print_S_reserved_uncert:n { mantissa }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_mantissa_aux:n #1 {
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { integer } {#1}
+  \_siunitx_table_print_S_get_integer:Nn
+    \_l_siunitx_number_out_prop {#1}
+  \box_clear:N \_l_siunitx_tmp_box
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+    }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_fill_box
+    { \_l_siunitx_table_integer_dim - \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { decimal } {#1}
+  \box_clear:N \_l_siunitx_tmp_box
+  \_siunitx_table_print_S_get_decimal:Nn
+    \_l_siunitx_number_out_prop {#1}
+  \tl_if_empty:NF \_l_siunitx_tmpa_tl
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+    }
+  \dim_set:Nn \_l_siunitx_table_gap_dim
+    {
+      \dim_use:N \_l_siunitx_table_decimal_dim -
+      \box_wd:N \_l_siunitx_tmp_box
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_uncert:n #1 {
+  \bool_if:NT \_l_siunitx_uncert_sep_bool
+    {
+      \intexpr_compare:nNnTF
+        { \int_use:N \_l_siunitx_table_uncert_int } > { 0 }
+        { \_siunitx_table_print_S_reserved_uncert_aux:n {#1} }
+        {
+          \prop_if_in:NnT \_l_siunitx_number_out_prop
+            { #1 -uncertainty }
+            {
+              \msg_error:nn { siunitx } { table-partial-number }
+                { an~uncertainty }
+            }
+        }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_uncert_aux:n #1 {
+  \_siunitx_table_print_S_reserved_uncert_pm:n {#1}
+  \_siunitx_table_print_S_reserved_mantissa_aux:n { #1 -uncertainty }
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { uncert } {#1}
+  \_siunitx_table_print_S_get_uncert:Nn \_l_siunitx_number_out_prop {#1}
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \_l_siunitx_table_uncert_dim }
+    {
+      \box_use:N \_l_siunitx_table_fill_box
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_uncert_pm:n #1 {
+  \tl_clear:N \_l_siunitx_tmpb_tl
+  \_siunitx_number_format_join_uncert_pm:
+  \tl_set:Nx \_l_siunitx_tmpb_tl
+    { { } \exp_not:V \_l_siunitx_tmpb_tl { } }
+  \hbox_set:Nn \_l_siunitx_table_result_box
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpb_tl }
+  \prop_if_in:NnF \_l_siunitx_number_out_prop { #1 -uncertainty }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+        { \box_wd:N \_l_siunitx_table_result_box } { \tex_hfil:D }
+    }
+ \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_reserved_exponent: {
+  \dim_zero:N \_l_siunitx_table_gap_dim
+  \_siunitx_table_print_S_reserved_exponent_product:
+  \_siunitx_table_print_S_measure:Nnn \_l_siunitx_table_model_prop
+    { exponent } { }
+  \_siunitx_table_print_S_get_exponent:Nn
+    \_l_siunitx_number_out_prop { }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \_l_siunitx_table_exponent_dim }
+    {
+      \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl
+      \tex_hfil:D
+    }
+  \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_exponent_product: {
+  \tl_clear:N \_l_siunitx_tmpa_tl
+  \box_clear:N \_l_siunitx_table_result_box
+  \prop_if_in:NnTF \_l_siunitx_table_model_prop { mantissa-result }
+    { \_siunitx_table_print_S_reserved_exponent_product_aux_i: }
+    {
+      \prop_if_in:NnT \_l_siunitx_table_model_prop { complex-result }
+        { \_siunitx_table_print_S_reserved_exponent_product_aux_i: }
+    }
+ \box_use:N \_l_siunitx_table_result_box
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_exponent_product_aux_i: {
+  \tl_set_eq:NN \_l_siunitx_tmpa_tl \_l_siunitx_exponent_product_tl
+  \bool_if:NT \_l_siunitx_tight_bool
+    {
+      \tl_set:Nx \_l_siunitx_tmpa_tl
+        { { \exp_not:V \_l_siunitx_tmpa_tl } }
+    }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \exp_not:N \_siunitx_ensuremath:n
+        { { } \exp_not:V \_l_siunitx_tmpa_tl { } }
+    }
+  \hbox_set:Nn \_l_siunitx_table_result_box
+    { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+  \prop_if_in:NnTF \_l_siunitx_number_out_prop { exponent-result }
+    {
+      \prop_if_in:NnF \_l_siunitx_number_out_prop { mantissa-result }
+        {
+          \prop_if_in:NnF \_l_siunitx_number_out_prop { complex-result }
+            {
+              \_siunitx_table_print_S_reserved_exponent_product_aux_ii:
+            }
+        }
+    }
+    { \_siunitx_table_print_S_reserved_exponent_product_aux_ii: }
+
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_reserved_exponent_product_aux_ii: {
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_result_box
+    { \box_wd:N \_l_siunitx_table_result_box } { \tex_hfil:D }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_measure:Nnn #1#2#3 {
+  \use:c { _siunitx_table_print_S_get_ #2 :Nn } #1 {#3}
+  \tl_if_empty:NTF \_l_siunitx_tmpa_tl
+    { \dim_set:cn { _l_siunitx_table_ #2 _dim } { \c_zero_skip } }
+    {
+      \hbox_set:Nn \_l_siunitx_tmp_box
+        { \_siunitx_print:nV { number } \_l_siunitx_tmpa_tl }
+      \dim_set:cn { _l_siunitx_table_ #2 _dim }
+        { \box_wd:N \_l_siunitx_tmp_box }
+    }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_get_decimal:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -decimal } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_get_exponent:Nn #1#2 {
+  \prop_get:NnN #1 { exponent-result } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_get_integer:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -sign } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+  \prop_get:NnN #1 { #2 -integer } \_l_siunitx_tmpb_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpb_tl
+    { \tl_clear:N \_l_siunitx_tmpb_tl }
+  \tl_put_right:NV \_l_siunitx_tmpa_tl \_l_siunitx_tmpb_tl
+}
+\cs_set_protected_nopar:Npn
+  \_siunitx_table_print_S_get_mantissa:Nn #1#2 {
+  \prop_get:NnN #1 { mantissa } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_marker:Nn #1#2 {
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    {
+      \exp_not:N \_siunitx_ensuremath:n
+        { \exp_not:V \_l_siunitx_output_decimal_tl }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_result:Nn #1#2 {
+  \prop_get:NnN #1 { result } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_print_S_get_uncert:Nn #1#2 {
+  \prop_get:NnN #1 { #2 -uncertainty } \_l_siunitx_tmpa_tl
+  \quark_if_no_value:NT \_l_siunitx_tmpa_tl
+    { \tl_clear:N \_l_siunitx_tmpa_tl }
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct: {
+  \m@th
+  \bool_if:NTF \_l_siunitx_table_center_decimal_bool
+    { \_siunitx_table_direct_centered: }
+    { \_siunitx_table_direct_reserved: }
+}
+\char_make_active:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered: {
+  \cs_set_eq:NN \_siunitx_table_print:
+    \_siunitx_table_direct_centered_end:
+  \hbox_set:Nn \_l_siunitx_tmp_box
+    { \_siunitx_ensuremath:n { \_l_siunitx_output_decimal_tl } }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }
+  \hbox_set:Nn \_l_siunitx_table_pre_box
+    \c_group_begin_token
+      \c_math_shift_token
+      \tl_map_function:NN \_l_siunitx_input_decimal_tl
+        \_siunitx_table_direct_centered_aux:N
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered_aux:N #1 {
+  \char_set_lccode:nn { `\@ } { `#1 }
+  \char_set_mathcode:nn { `#1 } { 32768 }
+  \tl_to_lowercase:n { \cs_set_nopar:Npn @ }
+    {
+      \c_math_shift_token
+      \c_group_end_token
+      \hbox_set:Nn \_l_siunitx_table_post_box
+        \c_group_begin_token
+          \c_math_shift_token
+          \_l_siunitx_output_decimal_tl
+    }
+}
+\char_make_letter:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_centered_end: {
+    \c_math_shift_token
+  \c_group_end_token
+  \dim_compare:nNnTF
+    { \box_wd:N \_l_siunitx_table_pre_box } >
+    { \box_wd:N \_l_siunitx_table_post_box }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_table_pre_box }
+        {
+          \hbox_unpack:N \_l_siunitx_table_post_box
+          \tex_hfil:D
+        }
+    }
+    {
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+        { \box_wd:N \_l_siunitx_table_post_box }
+        {
+          \tex_hfil:D
+          \hbox_unpack:N \_l_siunitx_table_pre_box
+        }
+    }
+  \box_use:N \_l_siunitx_table_pre_box
+  \box_use:N \_l_siunitx_table_post_box
+}
+\char_make_active:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved: {
+  \cs_set_eq:NN \_siunitx_table_print:
+    \_siunitx_table_direct_reserved_end:
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { \prg_replicate:nn { \_l_siunitx_table_integer_int } { 8 } }
+  \hbox_set:Nn \_l_siunitx_tmp_box
+    {
+      \_siunitx_ensuremath:n
+        {
+          \bool_if:NT \_l_siunitx_table_sign_mantissa_bool { - }
+          \_l_siunitx_tmpa_tl
+        }
+    }
+  \dim_set:Nn \_l_siunitx_table_integer_dim
+    { \box_wd:N \_l_siunitx_tmp_box }
+  \tl_set:Nx \_l_siunitx_tmpa_tl
+    { \prg_replicate:nn { \_l_siunitx_table_decimal_int } { 8 } }
+  \hbox_set:Nn \_l_siunitx_tmp_box
+    {
+      \_siunitx_ensuremath:n
+        {
+          \_l_siunitx_output_decimal_tl
+          \_l_siunitx_tmpa_tl
+        }
+    }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+    { \box_wd:N \_l_siunitx_tmp_box }
+    { \tex_hfil:D }
+  \hbox_set_to_wd:Nnn \_l_siunitx_table_pre_box
+    { \_l_siunitx_table_integer_dim }
+    \c_group_begin_token
+      \c_math_shift_token
+      \tl_map_function:NN \_l_siunitx_input_decimal_tl
+        \_siunitx_table_direct_reserved_aux:N
+      \tex_hfill:D
+}
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved_aux:N #1 {
+  \char_set_lccode:nn { `\@ } { `#1 }
+  \char_set_mathcode:nn { `#1 } { 32768 }
+  \tl_to_lowercase:n { \cs_set_nopar:Npn @ }
+    {
+        \c_math_shift_token
+      \c_group_end_token
+      \hbox_set_to_wd:Nnn \_l_siunitx_table_post_box
+        { \box_wd:N \_l_siunitx_tmp_box }
+        \c_group_begin_token
+          \c_math_shift_token
+          \_l_siunitx_output_decimal_tl
+    }
+}
+\char_make_letter:N \@
+\cs_set_protected_nopar:Npn \_siunitx_table_direct_reserved_end: {
+    \c_math_shift_token
+    \tex_hfil:D
+  \c_group_end_token
+  \_siunitx_table_align_left:n { \_l_siunitx_table_number_align_skip }
+  \box_use:N \_l_siunitx_table_pre_box
+  \box_use:N \_l_siunitx_table_post_box
+  \_siunitx_table_align_right:n { \_l_siunitx_table_number_align_skip }
+}
+\keys_define:nn { siunitx } {
+  redefine-symbols .bool_set:N = \_l_siunitx_redefine_symbols_bool,
+}
+\keys_set:nn { siunitx } {
+  redefine-symbols = true
+}
+\AtBeginDocument {
+  \bool_if:NT \_l_siunitx_redefine_symbols_bool
+    {
+      \@ifpackageloaded { textcomp }
+        {
+          \keys_set:nn { siunitx }
+            {
+              math-degree = \text { \textdegree },
+              text-degree  = \textdegree,
+            }
+          \@ifpackageloaded { mathptmx } { }
+            {
+              \keys_set:nn { siunitx } { text-micro = \textmu }
+              \@ifpackageloaded { fourier } { }
+                { \keys_set:nn { siunitx } { text-ohm = \textohm } }
+            }
+          \tl_if_eq:nVT { OT1 } \encodingdefault
+            {
+              \keys_set:nn { siunitx }
+                {
+                  math-angstrom = \text { \capitalring { A } },
+                  text-angstrom = \capitalring { A }
+                }
+            }
+        } { }
+      \@ifpackageloaded { upgreek }
+        {
+          \keys_set:nn { siunitx }
+            { math-ohm = \Upomega }
+        } { }
+    }
+}
+\keys_define:nn { siunitx } {
+  math-angstrom   .tl_set:N = \_l_siunitx_angstrom_math_tl,
+  math-arcminute  .tl_set:N = \_l_siunitx_arcminute_math_tl,
+  math-arcsecond  .tl_set:N = \_l_siunitx_arcsecond_math_tl,
+  math-celsius    .tl_set:N = \_l_siunitx_celsius_math_tl,
+  math-degree     .tl_set:N = \_l_siunitx_degree_math_tl,
+  math-micro      .tl_set:N = \_l_siunitx_micro_math_tl,
+  math-ohm        .tl_set:N = \_l_siunitx_ohm_math_tl
+}
+\keys_set:nn { siunitx } {
+  math-angstrom  = \text { \AA },
+  math-arcminute = { } ^ { \prime },
+  math-arcsecond = { } ^ { \prime \prime },
+  math-celsius   = { } ^ { \circ } \kern - \scriptspace \mathrm { C },
+  math-degree    = { } ^ { \circ },
+  math-micro     = \text { \_c_siunitx_mu_tl },
+  math-ohm       = \text { \ensuremath { \_c_siunitx_omega_tl } },
+}
+\keys_define:nn { siunitx } {
+  text-angstrom  .tl_set:N = \_l_siunitx_angstrom_text_tl,
+  text-arcminute .tl_set:N = \_l_siunitx_arcminute_text_tl,
+  text-arcsecond .tl_set:N = \_l_siunitx_arcsecond_text_tl,
+  text-celsius   .tl_set:N = \_l_siunitx_celsius_text_tl,
+  text-degree    .tl_set:N = \_l_siunitx_degree_text_tl,
+  text-micro     .tl_set:N = \_l_siunitx_micro_text_tl,
+  text-ohm       .tl_set:N = \_l_siunitx_ohm_text_tl,
+}
+\keys_set:nn { siunitx } {
+  text-angstrom  = \AA,
+  text-arcminute = \ensuremath { { } ^ { \prime } },
+  text-arcsecond = \ensuremath { { } ^ { \prime \prime } },
+  text-celsius   =
+    \ensuremath { { } ^ { \circ } \kern - \scriptspace \text { C } },
+  text-degree    = \ensuremath { { } ^ { \circ } },
+  text-micro     = \_c_siunitx_mu_tl ,
+  text-ohm       = \ensuremath { \_c_siunitx_omega_tl },
+}
+\cs_set_protected:Npn \_siunitx_symbol_new:n #1 {
+  \cs_set_protected_nopar:cpn { SIUnitSymbol #1 }
+    {
+      \mode_if_math:TF
+        { \tl_to_lowercase:n { \use:c { _l_siunitx_ #1 _math_tl } } }
+        { \tl_to_lowercase:n { \use:c { _l_siunitx_ #1 _text_tl } } }
+    }
+}
+\_siunitx_symbol_new:n { Angstrom }
+\_siunitx_symbol_new:n { Arcminute }
+\_siunitx_symbol_new:n { Arcsecond }
+\_siunitx_symbol_new:n { Celsius }
+\_siunitx_symbol_new:n { Degree }
+\_siunitx_symbol_new:n { Micro }
+\_siunitx_symbol_new:n { Ohm }
+\clist_new:N \_l_siunitx_pgf_link_clist
+\cs_set_protected_nopar:Npn \_siunitx_pgf_link: {
+  \clist_clear:N \_l_siunitx_pgf_link_clist
+  \tl_if_eq:VnT \_l_siunitx_round_tl { figure }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist { fixed }
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { fixed~zerofill = true }
+    }
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    { precision = \int_use:N \_l_siunitx_process_precision_int }
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    {
+      set~decimal~separator =
+        { { \exp_not:V \_l_siunitx_output_decimal_tl } }
+    }
+  \clist_put_right:Nx \_l_siunitx_pgf_link_clist
+    {
+      set~thousands~separator =
+        { \exp_not:V \_l_siunitx_group_sep_tl }
+    }
+  \bool_if:NTF \_l_siunitx_group_four_bool
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { min~exponent~for~1000~sep = 3 }
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { min~exponent~for~1000~sep = 4 }
+    }
+  \bool_if:nF
+    {
+      \_l_siunitx_group_decimal_bool ||
+      \_l_siunitx_group_integer_bool
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { min~exponent~for~1000~sep = 999 }
+    }
+  \bool_if:NTF \_l_siunitx_process_integer_zero_bool
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { skip~0. = false }
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { skip~0. = true }
+    }
+  \tl_if_eq:VnTF \_l_siunitx_process_sign_tl { + }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { showpos = true }
+    }
+    {
+      \clist_put_right:Nn \_l_siunitx_pgf_link_clist
+        { showpos = false }
+    }
+  \group_begin:
+  \cs_set_nopar:Npx \_siunitx_tmp:w
+    {
+      \group_end:
+      \exp_not:N \pgfqkeys
+        { /pgf/number~format }
+        { \exp_not:V \_l_siunitx_pgf_link_clist }
+    }
+  \_siunitx_tmp:w
+}
+\msg_set:nnnn { siunitx } { bad-arc-sign }
+  { Incorrect~use~of~sign~in~degree-minute-second~angle. }
+  { Only~the~highest~value~part~of~an~angle~can~have~a~sign. }
+\msg_set:nnnn { siunitx } { duplicate-complex-root-token }
+  { Duplicate~complex~root~token~'#1'~in~input. }
+  { Only~one~complex~root~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-decimal-token }
+  { Duplicate~decimal~marker~token~'#1'~in~input. }
+  { Only one decimal marker token can appear in a single number. }
+\msg_set:nnnn { siunitx } { duplicate-exponent-token }
+  { Duplicate~exponent~marker~token~'#1'~in~input. }
+  { Only~one~exponent~marker~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-quotient-token }
+  { Duplicate~quotient~token. }
+  { Only~one~quotient~token~can~appear~in~a~single~number. }
+\msg_set:nnnn { siunitx } { duplicate-sticky-per }
+  { Duplicate~\token_to_str:N \per. }
+  {
+    When~the~'sticky-per'~option~is~active,~only~one
+    \token_to_str:N \per \\
+    may~appear~in~a~unit.
+  }
+\msg_set:nnnn { siunitx } { empty-arc }
+  { Empty~degree-minute-second~angle. }
+  { The~angle~given~does~not~contain~any~numbers. }
+\msg_set:nnnn { siunitx } { empty-uncertainty }
+  { Empty~uncertainty~given~in~'#1'. }
+  { The~number~given~contains~an~empty~uncertainty. }
+\msg_set:nnnn { siunitx } { ending-product-token }
+  { Misplaced~product~token. }
+  { A~number~cannot~end~with~a~product~token. }
+\msg_set:nnnn { siunitx } { ending-quotient-token }
+  { Misplaced~quotient~token. }
+  { A~number~cannot~end~with~a~quotient~token. }
+\msg_set:nnnn { siunitx } { invalid-arc-format }
+  { Invalid~degree-minute-second angle~'#1'. }
+  {
+    Angles~given~in~degree-minute-second~format~should~contain~two~';'\\
+    symbols~to~divide~up~the~parts~of~the~input.\\
+  }
+\msg_set:nnnn { siunitx } { invalid-number }
+  { Invalid~numerical~input~'#1'. }
+  {
+    The~input given~as~a~number~does~not~make~logical~sense.\\
+    This~happens,~for example,~if~a~number~only~contains~a~sign.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-exponent }
+  { Invalid~exponent~in~numerical~input~'#1'. }
+  {
+    The~exponent`part~of~a~number~cannot~contain~an~uncertainty~or~
+    complex~part.\\
+    The~input~given~appears~to~contain~one~of~these~in~the~exponent.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-number }
+  { Invalid~token~'#1'~in~numerical~input. }
+  {
+    Numbers~can~only~contain~tokens~defined~using~the~
+    'input-...'~options:\\
+    the~token~'#1'~is~not~set~up~as~a~valid~part~of~a~number.
+  }
+\msg_set:nnnn { siunitx } { invalid-token-in-uncertainty }
+  { Invalid~uncertainty~in~numerical~input~'#1'. }
+  {
+    The~uncertainty~part~of~a~number~may~only~contain~digits~or~
+    symbols.
   }
+\msg_set:nnnn { siunitx } { literal-unit }
+  { Literal~units~disabled. }
+  {
+    You~gave~the~literal~input~'#1'\\
+    but~literal~unit~output~is~disabled.
+  }
+\msg_set:nnnn { siunitx } { misplaced-sign-token }
+  { Misplaced~sign~token~'#1'. }
+  { Sign~tokens~can~only~come~at~the~beginning~of~a~number. }
+\msg_set:nnnn { siunitx } { misplaced-complex-root-token }
+  { Misplaced~complex~token~in~numerical~input~'#1'. }
+  {
+    The~root~token~must~come~either~before~or~after~the~real~digits\\
+    of~the~complex~part.
+  }
+\msg_set:nnnn { siunitx } { misplaced-uncertainty-token }
+  { Misplaced~uncertainty~token~'#1'. }
+  {
+    The~uncertainty~in~a~number~must~be~given~between~a~set~of~
+    delimiters~as~defined~by~the\\
+    \c_space_tl \c_space_tl
+    'input-open-uncertainty'~and~'input-close-uncertainty'\\
+    options.
+  }
+\msg_set:nnnn { siunitx } { multi-part-range }
+  { Numerical~range~with~multiple~parts. }
+  {
+    The~input~'#1'~is~a~number~which~has~more~than~one~part.\\
+    Ranges~can~only~contain~one~number~in~each~part.
+  }
+\msg_set:nnn { siunitx } { option-not-available }
+  { Option~'#1'~not~available~in~strict~mode. }
+\msg_set:nnn { siunitx } { option-preamble-only }
+  { Option~'#1'~only~available~in~the~preamble. }
+\msg_set:nnnn { siunitx } { prefix-base-mismatch }
+  { Prefix~bases~do~not~match. }
+  {
+    You~have~asked~for~prefixes~to~be~converted~into~a~power,\\
+    but~the~bases~do~not~match.
+  }
+\msg_set:nnn { siunitx } { prefix-only }
+  { Prefix~with~no~unit. }
+\msg_set:nnnn { siunitx } { qualifier-before-unit }
+  { Qualifier~before~unit. }
+  { Unit~qualifiers~have~to~follow~after~units,~not~before~them. }
+\msg_set:nnnn { siunitx } { restricted-number }
+  { Token~'#1'~forbidden~in~restricted~numerical~input. }
+  {
+    The~current~input~must~be~a~real~number~and~cannot~contain: \\
+    \c_space_tl -~an~exponent; \\
+    \c_space_tl -~an~uncertainty; \\
+    \c_space_tl -~a~complex~part.
+  }
+\msg_set:nnnn { siunitx } { starting-product-token }
+  { Misplaced~product~token. }
+  { A~number~cannot~begin~with~a~product~token. }
+\msg_set:nnnn { siunitx } { starting-quotient-token }
+  { Misplaced~quotient~token. }
+  { A~number~cannot~begin~with~a~quotient~token. }
+\msg_set:nnnn { siunitx } { table-partial-number }
+  { No~space~reserved~for~#1~\msg_line_context:. }
+  {
+    The~number~in~the~current~table~cell~contains~#1~part, \\
+    but~you~did~not~reserve~any~space~to~print~it: \\
+    it~will~be~missing~in~the~output.
+  }
+\msg_set:nnnn { siunitx } { unknown-configuration-file }
+  { Unknown~configuration~'#1'. }
+  { The~configuration~file~'siunitx-#1.cfg'~was~not~found. }
+\msg_set:nnnn { siunitx } { unknown-option }
+  { Unknown~option~'#1'. }
+  {
+    The~option~file~'#1'~is~not~known~by~siunitx: \\
+    perhaps~it~is~spelled~incorrectly.
+  }
+\cs_set_protected_nopar:Npn \DeclareBinaryPrefix #1#2#3 {
+  \_siunitx_declare_prefix:Nnnn #1 {#2} { 2 } {#3}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPostPower #1#2 {
+  \_siunitx_declare_power_after:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPrefix #1#2#3 {
+  \_siunitx_declare_prefix:Nnnn #1 {#2} { 10 } {#3}
+}
+\cs_set_protected_nopar:Npn \DeclareSIPrePower #1#2 {
+  \_siunitx_declare_power_before:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIQualifier #1#2 {
+  \_siunitx_declare_qualifier:Nn #1 {#2}
+}
+\cs_set_protected_nopar:Npn \DeclareSIUnit #1#2 {
+  \_siunitx_declare_unit:Nnn #1 {#2} { }
+}
+\cs_set_protected_nopar:Npn \DeclareSIUnitWithOptions #1#2#3 {
+  \_siunitx_declare_unit:Nnn #1 {#2} {#3}
+}
+\@onlypreamble \DeclareBinaryPrefix
+\@onlypreamble \DeclareSIPostPower
+\@onlypreamble \DeclareSIPrefix
+\@onlypreamble \DeclareSIPrePower
+\@onlypreamble \DeclareSIQualifier
+\@onlypreamble \DeclareSIUnit
+\@onlypreamble \DeclareSIUnitWithOptions
+\cs_set_protected_nopar:Npn \SendSettingsToPgf { \_siunitx_pgf_link: }
+\@onlypreamble \SendSettingsToPgf
+\NewDocumentCommand \ang { o > { \SplitArgument { 2 } { ; } } m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_angle_output:nnn #2
+  \group_end:
+}
+\NewDocumentCommand \num { o m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_number_output:n {#2}
+  \group_end:
+}
+\NewDocumentCommand \numlist { o > { \SplitList { ; } } m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_list_numbers:n {#2}
+  \group_end:
+}
+\NewDocumentCommand \numrange { o m m } {
+  \group_begin:
+    \IfNoValueF {#1}
+      { \keys_set:nn { siunitx } {#1} }
+    \_siunitx_range_numbers:nn {#2} {#3}
+  \group_end:
+}
+\NewDocumentCommand \si { o m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_unit_output:nn {#2} { } }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_unit_output:nn {#2} {#1}
+      }
+  \group_end:
+}
+\NewDocumentCommand \SIlist { o > { \SplitList { ; } } m m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_list_units:nnn {#2} {#3} { }  }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_list_units:nnn {#2} {#3} {#1}
+      }
+  \group_end:
+}
+\NewDocumentCommand \SIrange { o m m m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_range_unit:nnnn {#4} { } {#2} {#3} }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_range_unit:nnnn {#4} {#1} {#2} {#3}
+      }
+  \group_end:
+}
+\NewDocumentCommand \SI { o m o m } {
+  \group_begin:
+    \IfNoValueTF {#1}
+      { \_siunitx_combined:nnnn { } {#2} {#3} {#4} }
+      {
+        \keys_set:nn { siunitx } {#1}
+        \_siunitx_combined:nnnn {#1} {#2} {#3} {#4}
+      }
+  \group_end:
+}
+\NewDocumentCommand \sisetup { m } {
+  \keys_set:nn { siunitx } {#1}
+}
+\AtBeginDocument {
+  \cs_set:Npn \addtocontents #1#2
+    {
+      \protected@write \@auxout
+        {
+          \cs_set_eq:NN \label \use_none:n
+          \cs_set_eq:NN \index \use_none:n
+          \cs_set_eq:NN \glossary\use_none:n
+          \tl_map_function:NN \_l_siunitx_declare_list_tl
+            \_siunitx_contents_add:N
+        }
+        { \token_to_str:N \@writefile {#1} {#2} }
+    }
+}
+\cs_set_protected_nopar:Npn \_siunitx_contents_add:N #1 {
+  \cs_set_nopar:Npn #1 { \token_to_str:N #1 }
+}
+\cs_set_protected_nopar:Npn \_siunitx_contents_bookmarks: {
+  \tl_map_function:NN \_l_siunitx_declare_list_tl
+    \_siunitx_unit_print_literal_aux:N
+  \msg_redirect_name:nnn { LaTeX / xparse } { redefine-command }
+    { none }
+  \cs_set_eq:NN \num      \_siunitx_bookmark_num:w
+  \cs_set_eq:NN \numrange \_siunitx_bookmark_numrange:w
+  \cs_set_eq:NN \si       \_siunitx_bookmark_si:w
+  \cs_set_eq:NN \SI       \_siunitx_bookmark_SI:w
+  \cs_set_eq:NN \SIrange  \_siunitx_bookmark_SIrange:w
+  \cs_set_nopar:Npn \SIUnitSymbolAngstrom  { \AA }
+  \cs_set_nopar:Npn \SIUnitSymbolArcminute { ' }
+  \cs_set_nopar:Npn \SIUnitSymbolArcsecond { '' }
+  \cs_set_nopar:Npn \SIUnitSymbolCelsius   { \textcelsius }
+  \cs_set_nopar:Npn \SIUnitSymbolDegree    { \textdegree }
+  \cs_set_nopar:Npn \SIUnitSymbolMicro     { \textmu }
+  \cs_set_nopar:Npn \SIUnitSymbolOhm       { [ohm] }
+}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_num:w { o m } {#2}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_numrange:w { o m m }
+  { #2 \_l_siunitx_range_phrase_tl #3 }
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_si:w { o m } {#2}
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_SI:w { o m o m }
+  { \IfNoValueF {#3} {#3} #2 ~ #4 }
+\DeclareExpandableDocumentCommand \_siunitx_bookmark_SIrange:w
+  { o m m m } { #2 ~ #4 \_l_siunitx_range_phrase_tl #3 ~ #4 }
+\AtBeginDocument {
+  \@ifpackageloaded { hyperref }
+    { \pdfstringdefDisableCommands { \_siunitx_contents_bookmarks: } }
+    { }
+}
+\DeclareSIUnit \kilogram { \kilo \gram }
+\DeclareSIUnit \metre    { m }
+\DeclareSIUnit \meter    { \metre }
+\DeclareSIUnit \mole     { mol }
+\DeclareSIUnit \second   { s }
+\DeclareSIUnit \ampere   { A }
+\DeclareSIUnit \kelvin   { K }
+\DeclareSIUnit \candela  { cd }
+\DeclareSIUnit \gram { g }
+\DeclareSIPrefix \yocto { y } { -24 }
+\DeclareSIPrefix \zepto { z } { -21 }
+\DeclareSIPrefix \atto  { a } { -18 }
+\DeclareSIPrefix \femto { f } { -15 }
+\DeclareSIPrefix \pico  { p } { -12 }
+\DeclareSIPrefix \nano  { n } { -9 }
+\DeclareSIPrefix \micro { \SIUnitSymbolMicro } { -6 }
+\DeclareSIPrefix \milli { m } { -3 }
+\DeclareSIPrefix \centi { c } { -2 }
+\DeclareSIPrefix \deci  { d } { -1 }
+\DeclareSIPrefix \deca  { da } { 1 }
+\DeclareSIPrefix \deka  { da } { 1 }
+\DeclareSIPrefix \hecto { h }  { 2 }
+\DeclareSIPrefix \kilo  { k }  { 3 }
+\DeclareSIPrefix \mega  { M }  { 6 }
+\DeclareSIPrefix \giga  { G }  { 9 }
+\DeclareSIPrefix \tera  { T }  { 12 }
+\DeclareSIPrefix \peta  { P }  { 15 }
+\DeclareSIPrefix \exa   { E }  { 18 }
+\DeclareSIPrefix \zetta { Z }  { 21 }
+\DeclareSIPrefix \yotta { Y }  { 24 }
+\DeclareSIUnit \becquerel     { Bq }
+\DeclareSIUnit \celsius       { \SIUnitSymbolCelsius }
+\DeclareSIUnit \degreeCelsius { \SIUnitSymbolCelsius }
+\DeclareSIUnit \coulomb       { C }
+\DeclareSIUnit \farad         { F }
+\DeclareSIUnit \gray          { Gy }
+\DeclareSIUnit \hertz         { Hz }
+\DeclareSIUnit \henry         { H }
+\DeclareSIUnit \joule         { J }
+\DeclareSIUnit \katal         { kat }
+\DeclareSIUnit \lumen         { lm }
+\DeclareSIUnit \lux           { lx }
+\DeclareSIUnit \newton    { N }
+\DeclareSIUnit \ohm       { \SIUnitSymbolOhm }
+\DeclareSIUnit \pascal    { Pa }
+\DeclareSIUnit \radian    { rad }
+\DeclareSIUnit \siemens   { S }
+\DeclareSIUnit \sievert   { Sv }
+\DeclareSIUnit \steradian { sr }
+\DeclareSIUnit \tesla     { T }
+\DeclareSIUnit \volt      { V }
+\DeclareSIUnit \watt      { W }
+\DeclareSIUnit \weber     { Wb }
+\DeclareSIUnitWithOptions \arcmin { \arcminute }
+  { number-unit-separator = }
+\DeclareSIUnitWithOptions \arcminute { \SIUnitSymbolArcminute }
+  { number-unit-separator = }
+\DeclareSIUnitWithOptions \arcsecond { \SIUnitSymbolArcsecond }
+  { number-unit-separator = }
+\DeclareSIUnit \day { d }
+\DeclareSIUnitWithOptions \degree { \SIUnitSymbolDegree }
+  { number-unit-separator = }
+\DeclareSIUnit \hectare { ha }
+\DeclareSIUnit \hour    { h }
+\DeclareSIUnit \litre   { l }
+\DeclareSIUnit \liter   { L }
+\DeclareSIUnit \minute  { min }
+\DeclareSIUnit \percent { \char 37 }
+\DeclareSIUnit \tonne   { t }
+\DeclareSIUnit \astronomicalunit { ua }
+\DeclareSIUnit \atomicmassunit   { u }
+\DeclareSIUnit \electronvolt     { eV }
+\DeclareSIUnit \dalton           { Da }
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \DeclareSIUnit \clight { \text { \ensuremath { c @ { 0 } } } }
+  \DeclareSIUnit \electronmass
+    { \text { \ensuremath { m @ { \text { e } } } } }
+}
+\DeclareSIUnit \planckbar { \text { \ensuremath { \hbar } } }
+\DeclareSIUnit \elementarycharge { \text { \ensuremath { e } } }
+\group_begin:
+  \char_set_lccode:nn { `\@ } { `\_ }
+  \char_make_math_subscript:N \@
+\tl_to_lowercase:n {
+  \group_end:
+  \DeclareSIUnit \bohr { \text { \ensuremath { a @ { 0 } } } }
+  \DeclareSIUnit \hartree
+    { \text { \ensuremath { E @ { \textup { h } } } } }
+}
+\DeclareSIUnit \angstrom     { \SIUnitSymbolAngstrom }
+\DeclareSIUnit \bar          { bar }
+\DeclareSIUnit \barn         { b }
+\DeclareSIUnit \bel          { B }
+\DeclareSIUnit \decibel      { \deci \bel }
+\DeclareSIUnit \knot         { kn }
+\DeclareSIUnit \mmHg         { mmHg }
+\DeclareSIUnit \nauticalmile { M }
+\DeclareSIUnit \neper        { Np }
+\DeclareSIPrePower  \square  { 2 }
+\DeclareSIPostPower \squared { 2 }
+\DeclareSIPrePower  \cubic   { 3 }
+\DeclareSIPostPower \cubed   { 3 }
+\NewDocumentCommand \requiresiconfigs { m } {
+  \keys_set:nn { siunitx } { load-configurations = version-1 }
+  \clist_map_function:nN {#1} \_siunitx_requireconfig:n
 }
-\newcommand*{\si@unt@addvaluesep}{%
-  \ifsi@unt@num
-    \expandafter\si@unt@addvalsep
-  \fi}
-\newcommand*{\si@unt@addvalsep}{%
-  \ifsi@unt@litout
-    \expandafter\si@unt@litvalsep
-  \else
-    \expandafter\si@unt@stackvalsep
-  \fi}
-\newcommand*{\si@unt@stackvalsep}{%
-  \protected@edef\si@unt@spstack{\si@valuesep}}
-\newcommand*{\si@unt@litvalsep}{%
-  \nobreak\ensuremath{\si@valuesep}\nobreak}
-\newcommand*{\si@unt@spstack}{}
-\newcommand*{\si@unt@stacka}{}
-\newcommand*{\si@unt@stackb}{}
-\newcount\si@unt@unitcnta
-\newcount\si@unt@unitcntb
-\newcount\si@unt@depthcnt
-\newif\ifsi@unt@first
-\si@unt@depthcnt\m@ne\relax
-\newcommand*{\si@unt@init}{%
-  \begingroup
-    \si@unt@litoutfalse
-    \si@unt@litprefixfalse
-    \si@unt@firsttrue
-    \si@unt@perfalse
-    \si@unt@perseenfalse
-    \si@unt@prepowerfalse
-    \si@unt@depthcnt\z@\relax
-    \si@unt@powerdim\z@\relax
-    \si@unt@unitcnta\z@\relax
-    \si@unt@unitcntb\z@\relax
-    \si@unt@prefixcnt\z@\relax
-    \renewcommand*{\si@unt@spstack}{}%
-    \renewcommand*{\si@unt@stacka}{}%
-    \renewcommand*{\si@unt@stackb}{}%
-    \renewcommand*{\si@unt@spacestacka}{}%
-    \renewcommand*{\si@unt@spacestackb}{}%
-    \renewcommand*{\si@unt@lastadda}{space}%
-    \renewcommand*{\si@unt@lastaddb}{space}}
-\newcommand*{\si@unt@final}{%
-    \si@unt@third
-    \si@unt@stackout
-  \endgroup
-  \ifsi@xspace
-    \expandafter\expandafter\expandafter\xspace
-  \fi}
-\newcommand*{\si@unt@defunit}[3][]{%
-  \si@log@debug{Declaring unit \string#2 with \MessageBreak
-    meaning \string#3}%
-  \si@ifnotmtarg{#1}
-    {\expandafter\@namedef\expandafter{%
-      \expandafter\@gobble\string#2@opt@unt@si}{#1}}%
-  \protected\def#2{%
-    \ifsi@allowoptarg
-      \expandafter\si@unt@withopt
-    \else
-      \expandafter\si@unt@noopt
-    \fi
-    {#2}{#3}}}
-\newcommand*{\si@unt@withopt}[2]{%
-  \@ifnextchar[%]
-    {\si@unt@opt{#1}{#2}}
-    {\si@unt@opt{#1}{#2}[]}}
-\newcommand*{\si@unt@noopt}[2]{\si@unt@opt{#1}{#2}[]}
-\def\si@unt@opt#1#2[#3]{%
-  \ifsi@unt@littest
-    \expandafter\si@gobblethree
-  \else
-    \ifsi@unt@litout
-      \expandafter\expandafter\expandafter\@gobbletwo
-    \else
-      \expandafter\expandafter\expandafter\si@unt@unit
-    \fi
-  \fi
-  {#3}{#1}{#2}}
-\long\def\si@gobblethree #1#2#3{}
-\newif\ifsi@unt@litprefix
-\si@unt@litprefixtrue
-\newcommand*{\si@unt@defprefix}[4][]{%
-  \si@log@debug{Declaring multiple \string#1 with\MessageBreak
-    meaning \string#4}%
-  \expandafter\expandafter\expandafter\def\expandafter
-    \csname\expandafter\@gobble\string#2@opt@si\endcsname{#1}%
-  \protected\def#2{%
-    \ifsi@unt@littest
-      \expandafter\si@gobblethree
-    \else
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\@gobbletwo
-      \else
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-          \expandafter\expandafter\expandafter\expandafter
-            \expandafter\expandafter\expandafter\@gobbletwo
-        \else
-          \expandafter\expandafter\expandafter\expandafter
-            \expandafter\expandafter\expandafter\si@unt@prefix
-        \fi
-      \fi
-    \fi
-    {#2}{#3}{#4}}}
-\newcommand*{\si@unt@defpower}[3][]{%
-  \si@log@debug{Declaring power \string#2 with\MessageBreak
-    meaning \string#3}%
-  \expandafter\expandafter\expandafter\def\expandafter
-    \csname\expandafter\@gobble\string#2@opt@si\endcsname{#1}%
-  \protected\def#2{%
-    \ifsi@unt@littest
-      \expandafter\@gobbletwo
-    \else
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\si@unt@litpower
-      \else
-        \expandafter\expandafter\expandafter\si@unt@power
-      \fi
-    \fi
-    {#2}{#3}}}
-\newcommand*{\si@unt@defqual}[2]{%
-  \si@log@debug{Declaring qualifier \string#1 with\MessageBreak
-    meaning \string#2}%
-  \protected\def#1{%
-    \ifsi@unt@littest
-      \expandafter\@gobble
-    \else
-      \ifsi@unt@litout
-        \expandafter\expandafter\expandafter\si@unt@litqual
-      \else
-        \expandafter\expandafter\expandafter\si@unt@qual
-      \fi
-    \fi
-    {#2}}}
-\newcommand*{\si@unt@unithook}{}
-\newcommand*{\si@unt@unit}[3]{%
-  \ifnum\si@unt@depthcnt=\m@ne\relax
-    \expandafter\si@unt@init
-  \fi
-  \advance\si@unt@depthcnt\@ne\relax
-  \si@log@debug{Unit processing: level \the\si@unt@depthcnt,
-    \MessageBreak unit \string#2}%
-  \si@unt@firstorsecond{#1}{#2}%
-  \si@unt@ifliteral{#3}
-    {\si@unt@addtostack{unit}{#3}%
-     \ifsi@unt@prepower
-       \expandafter\si@unt@stkpower
-     \fi}
-    {#3}%
-  \advance\si@unt@depthcnt\m@ne\relax
-  \ifnum\si@unt@depthcnt=\z@\relax
-    \expandafter\si@unt@final
-  \fi}
-\newcommand*{\si@unt@firstorsecond}[2]{%
-  \ifsi@unt@first
-    \expandafter\si@unt@first
-  \else
-    \expandafter\si@unt@second
-  \fi
-  {#1}{#2}}%
-\newcommand*{\si@unt@first}[2]{%
-  \si@ifnotmtarg{#1}
-    {\num{#1}%
-     \si@unt@numtrue}%
-  \si@unt@unithook
-  \ifcsname\expandafter\@gobble\string#2@opt@unt@si\endcsname
-    \expandafter\si@unt@setopts
-  \else
-    \expandafter\@gobble
-  \fi
-  {#2}%
-  \si@unt@addvaluesep
-  \si@unt@firstfalse}
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-  \expandafter\expandafter\expandafter\expandafter\expandafter
-    \expandafter\expandafter\si@temptoks\expandafter
-    \expandafter\expandafter\expandafter\expandafter
-    \expandafter\expandafter{\expandafter%
-      \csname\expandafter\@gobble\string#1@opt@unt@si%
-      \endcsname}%
-  \expandafter\sisetup\expandafter{\the\si@temptoks}%
-  \si@log@debug{Applying options `\the\si@temptoks'
-    for\MessageBreak unit \string#1}%
-  \@ifundefined{si@unt@SIopts}{}
-    {\ifx\@empty\si@unt@SIopts\@empty\else
-       \expandafter\expandafter\si@unt@setSIopts
-     \fi}}
-\newcommand*{\si@unt@setSIopts}{%
-  \expandafter\si@temptoks\expandafter{\si@unt@SIopts}%
-  \expandafter\sisetup\expandafter{\the\si@temptoks}}
-\newcommand*{\si@unt@second}[2]{%
-  \si@ifnotmtarg{#1}
-    {\si@log@warn{Optional argument to unit macro\MessageBreak
-       allowed only for outer unit}}%
-  \si@unt@third
-  \si@unt@addtostack{space}{\ensuremath{\si@unitsep}}}
-\newcommand*{\si@unt@third}{%
-  \ifsi@unt@prepower\else
-    \expandafter\si@unt@stkpower
-  \fi
-  \renewcommand*{\si@tempa}{prefix}%
-  \expandafter\ifx
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-  \ifsi@unt@per
-    \expandafter\si@unt@perseentrue
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-  \si@unt@firstorsecond{}{#1}%
-  \ifsi@prefixsymbolic
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-  \else
-    \expandafter\si@unt@countprefix
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-  {#1}{#2}{#3}}
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-  \si@unt@addtostack{prefix}{#3}}
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-  {prefixbase=two}%
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-  \si@tempcnta -\si@tempcntb\relax}
-\newcommand*{\si@unt@litpower}[2]{\textsuperscript{#2}}
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-  \fi}
-\newdimen\si@unt@powerdim
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-  \si@unt@stkpower
-  \ifsi@stickyper\else
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-  \si@ifloaded{#1}{}
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-      :\expandafter=\csname si@#1\endcsname\do{%
-      \ifx\si@tempa\si@tempb
-        \si@addtolist{\si@tempc}{#2}%
-      \else
-        \si@addtolist{\si@tempc}{\si@tempa}%
-      \fi}
-    \expandafter\edef\csname si@#1\endcsname{\si@tempc}%
-    \expandafter\si@addtolist\expandafter{%
-      \csname si@no#1\endcsname}%
-      {default}%
-    \renewcommand*{\si@tempc}{}%
-    \expandafter\@for\expandafter\si@tempa\expandafter
-      :\expandafter=\csname si@#1\endcsname\do{%
-      \si@switchfalse
-      \expandafter\@for\expandafter\si@tempb\expandafter
-        :\expandafter=\csname si@no#1\endcsname\do{%
-        \ifx\si@tempa\si@tempb
-          \si@switchtrue
-        \fi
-        \ifsi@switch\else
-          \si@addtolist{\si@tempc}{\si@tempa}%
-        \fi}}
-    \@for\si@tempa:=\si@tempc\do{%
-      \si@loadfile{\si@tempa}}%
-  \fi}
-\si@expanddefault{load}{prefix,named,addn,prefixed,accepted,%
-  physical,abbr}
-\IfFileExists{siunitx.cfg}
-  {\si@log@inf{Local configuration file found}%
-   \InputIfFileExists{siunitx.cfg}{}{}}
-  {}
-\si@catcodes
+\cs_set_protected_nopar:Npn \_siunitx_requireconfig:n #1 {
+  \tl_if_eq:nnT {#1} { synchem }
+    { \keys_set:nn { siunitx } { load-configurations = chemistry } }
+}
+\keys_define:nn { siunitx } {
+  strict .code:n =
+    {
+      \keys_set:nn { siunitx }
+        {
+          bracket-numbers       = true,
+          detect-italic         = false,
+          detect-mode           = false,
+          detect-weight         = false,
+          multi-part-units      = bracket,
+          parse-numbers         = true,
+          parse-units           = true,
+          product-units         = repeat,
+        }
+      \_siunitx_strict_option:n
+        {
+          bracket-numbers       ,
+          detect-italic         ,
+          detect-mode           ,
+          detect-weight         ,
+          multi-part-units      ,
+          parse-numbers         ,
+          parse-units           ,
+          product-units         ,
+        }
+      \keys_define:nn { siunitx }
+        {
+          per-mode / repeated-symbol .code:n =
+            {
+              \msg_warning:nnx { siunitx } { option-not-available }
+                {  per-mode~=~repeated-symbol }
+            }
+        }
+    }
+}
+\_siunitx_option_deactivate:n { strict }
+\cs_set_protected_nopar:Npn \_siunitx_strict_option:n #1 {
+  \clist_map_function:nN {#1} \_siunitx_strict_option_aux:n
+}
+\cs_set_protected_nopar:Npn \_siunitx_strict_option_aux:n #1 {
+  \keys_define:nn { siunitx }
+    { #1 .code:n =
+      { \msg_warning:nnx { _siunitx} { option-not-available } {#1} }
+    }
+}
+\keys_define:nn { siunitx } {
+  load-configurations .code:n =
+    { \_siunitx_load_configuration:n {#1} }
+}
+\cs_set_protected:Npn \_siunitx_load_configuration:n #1 {
+  \tl_set_rescan:Nnn \_l_siunitx_tmpa_tl
+    { \char_make_ignore:N \ } {#1}
+  \clist_map_function:NN \_l_siunitx_tmpa_tl
+    \_siunitx_load_configuration_aux:n
+}
+\cs_set_protected:Npn \_siunitx_load_configuration_aux:n #1 {
+  \tl_if_empty:nF {#1}
+    {
+      \file_if_exist:nTF
+        { siunitx- #1 . \_c_siunitx_configuration_ext_tl }
+        {
+          \@onefilewithoptions { siunitx- #1 } [ ] [ ]
+          \_c_siunitx_configuration_ext_tl
+        }
+        {
+          \msg_error:nnx { siunitx } { unknown-configuration-file } {#1}
+        }
+    }
+}
+\tl_new:N \_c_siunitx_configuration_ext_tl
+\tl_set:Nn \_c_siunitx_configuration_ext_tl { cfg }
+\file_if_exist:nT { siunitx . \_c_siunitx_configuration_ext_tl }
+  {
+    \@onefilewithoptions { siunitx } [ ] [ ]
+      \_c_siunitx_configuration_ext_tl
+  }
+\ProcessKeysOptions { siunitx }
 %% 
 %% Copyright (C) 2008-2010 by
 %%   Joseph Wright <joseph.wright@morningstar2.co.uk>
@@ -3984,11 +5766,8 @@
 %% 
 %% This work consists of the file  siunitx.dtx
 %%           and the derived files siunitx.pdf,
-%%                                 siunitx.sty
-%%                                 siunitx.bib,
-%%                                 siunitx.ins,
-%%                                 siunitx-bug.tex and
-%%                                 various .cfg files.
+%%                                 siunitx.sty and
+%%                                 siunitx.ins.
 %% 
 %%
 %% End of file `siunitx.sty'.