skeyval 0.6 (30apr10)

git-svn-id: svn://tug.org/texlive/trunk@18059 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 2199 insertions, 1040 deletions

diff --git a/Master/texmf-dist/tex/latex/skeyval/skeyval.sty b/Master/texmf-dist/tex/latex/skeyval/skeyval.sty
index 2f8ed0862be..203a412dbc4 100644
--- a/Master/texmf-dist/tex/latex/skeyval/skeyval.sty
+++ b/Master/texmf-dist/tex/latex/skeyval/skeyval.sty
@@ -1,24 +1,24 @@
-%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
-%                                                                                    %
-% This is file 'skeyval.sty', version 0.5.                                           %
-%                                                                                    %
-% Please see the package documentation for user guide.                               %
-%                                                                                    %
-% This package and accompanying files may be distributed and/or modified under       %
-% the conditions of the LaTeX Project Public License, either version 1.3 of          %
-% this license or any later version. The latest version of this license is in        %
-% http://www.latex-project.org/lppl.txt and version 1.3 or later is part of all      %
-% distributions of LaTeX version 2005/12/01 or later.                                %
-%                                                                                    %
-% The LPPL maintenance status of this software is 'author-maintained'.               %
-%                                                                                    %
-% This software is provided 'as it is', without warranty of any kind, either         %
-% expressed or implied, including, but not limited to, the implied warranties of     %
-% merchantability and fitness for a particular purpose.                              %
-%                                                                                    %
-% Copyright (c) 2010 Ahmed Musa (a.musa@rocketmail.com).                             %
-%                                                                                    %
-%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
+%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
+%                                                                          %
+% This is file 'skeyval.sty', version 0.6.                                 %
+%                                                                          %
+% This package and accompanying files may be distributed and/or            %
+% modified under the conditions of the LaTeX Project Public License,       %
+% either version 1.3 of this license or any later version. The latest      %
+% version of this license is in http://www.latex-project.org/lppl.txt      %
+% and version 1.3 or later is part of all distributions of LaTeX           %
+% version 2005/12/01 or later.                                             %
+%                                                                          %
+% The LPPL maintenance status of this software is 'author-maintained'.     %
+%                                                                          %
+% This software is provided 'as it is', without warranty of any kind,      %
+% either expressed or implied, including, but not limited to, the          %
+% implied warranties of merchantability and fitness for a particular       %
+% purpose.                                                                 %
+%                                                                          %
+% Copyright (c) 2010 Ahmed Musa (a.musa@rocketmail.com).                   %
+%                                                                          %
+%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
 
 \begingroup
 \catcode064 11% @
@@ -35,372 +35,1240 @@
 }
 \SKV@tempa
 \catcode035 06% #
+\catcode061 12% =
 \catcode064 11% @
 \catcode123 01% {
 \catcode125 02% }
-\def\SKV@ensurecode#1#2{%
+\def\SKV@setcode#1#2{%
   \edef\SKV@restorecodes{%
     \SKV@restorecodes
     \catcode#1 \the\catcode#1\relax
   }%
   \catcode#1 #2\relax
 }
-\AtEndOfPackage{\SKV@restorecodes}
-\SKV@ensurecode{061}{12}% =
-\SKV@ensurecode{044}{12}% ,
-\SKV@ensurecode{058}{12}% :
-\SKV@ensurecode{059}{12}% ;
-\SKV@ensurecode{010}{12}% ^^J
-\SKV@ensurecode{126}{13}% ~
+\AtEndOfPackage{%
+  \SKV@AfterPackageEnd{%
+    \SKV@restorecodes
+    \SKV@Undef?{\SKV@setcode\SKV@restorecodes}%
+  }%
+}
+\SKV@setcode{010}{12}% ^^J
+\SKV@setcode{036}{03}% $
+\SKV@setcode{038}{03}% &
+\SKV@setcode{040}{12}% (
+\SKV@setcode{041}{12}% )
+\SKV@setcode{042}{12}% *
+\SKV@setcode{043}{12}% +
+\SKV@setcode{044}{12}% ,
+\SKV@setcode{045}{12}% -
+\SKV@setcode{047}{12}% /
+\SKV@setcode{058}{12}% :
+\SKV@setcode{059}{12}% ;
+\SKV@setcode{063}{12}% ?
+\SKV@setcode{091}{12}% [
+\SKV@setcode{093}{12}% ]
+\SKV@setcode{096}{12}% `
+\SKV@setcode{126}{13}% ~
 \def\SKV@rcsid$#1: #2 #3 #4 #5${#4 v#3}
 \ProvidesPackage{skeyval}%
-  [\SKV@rcsid $Id: skeyval.sty,v 0.5 2010/02/26 09:00:00 Ahmed Musa $
+  [\SKV@rcsid $Id: skeyval.sty,v 0.6 2010/04/20 09:00:00 Ahmed Musa $
   Extensions to the xkeyval parser (AM)]
 \NeedsTeXFormat{LaTeX2e}[1996/12/01]
-\@ifpackageloaded{xkeyval}\relax{\RequirePackage{xkeyval}[2008/08/13]}
 \ifnum0=0%
-  \ifx\eTeXversion\SKV@undefined 1\else\ifnum\eTeXversion<\tw@ 1\fi\fi
+  \ifx\eTeXversion\SKV@undefined1\else\ifnum\eTeXversion<\tw@1\fi\fi
 \else
-  \@latex@error{eTeX not loaded or old version}{%
-    This package requires eTeX version 2 or later.}%
+  \PackageError{skeyval}{eTeX not loaded or old version}%
+    {This package requires eTeX version 2 or later.}%
+  \endinput
 \fi
-\@ifdefinable\SKV@ifdefinable\relax
+\newtoks\SKV@toks
+\newcount\SKV@depth
+\def\@nil{\@unexpandable@protect\@nil}
+\def\@nnil{\@nil}
+\long\def\SKV@car#1#2\@nil{#1}
+\long\def\SKV@cdr#1#2\@nil{#2}
+\long\def\SKV@carcube#1#2#3#4\@nil{#1#2#3}
+\long\def\@firstofthree#1#2#3{#1}
+\long\def\@secondofthree#1#2#3{#2}
+\long\def\@thirdofthree#1#2#3{#3}
+\newcommand*\@threeexpafter{\expandafter\expandafter\expandafter}
+\def\SKV@aftercs#1#2{\expandafter#1\csname#2\endcsname}
+\def\SKV@xaftercs#1#2{\@threeexpafter#1\csname#2\endcsname}
+\SKV@aftercs\let{SKV@1of1}\@firstofone
+\SKV@aftercs\let{SKV@1of2}\@firstoftwo
+\SKV@aftercs\let{SKV@2of2}\@secondoftwo
+\SKV@aftercs\let{SKV@1of3}\@firstofthree
+\SKV@aftercs\let{SKV@2of3}\@secondofthree
+\SKV@aftercs\let{SKV@3of3}\@thirdofthree
+\def\SKV@ifx#1#2{\@nameuse{SKV@\ifx#1#21\else2\fi of2}}
+\def\SKV@unifx#1#2{\@nameuse{SKV@\ifx#1#22\else1\fi of2}}
+\def\SKV@csifx#1#2{\begingroup\expandafter\endgroup\expandafter
+  \SKV@ifx\csname#1\endcsname#2}
+\def\SKV@uncsifx#1#2{\begingroup\expandafter\endgroup\expandafter
+  \SKV@unifx\csname#1\endcsname#2}
+\def\SKV@ifxcs#1#2{\begingroup\expandafter\endgroup\expandafter
+  \SKV@ifx\expandafter#1\csname#2\endcsname}
+\def\SKV@unifxcs#1#2{\begingroup\expandafter\endgroup\expandafter
+  \SKV@unifx\expandafter#1\csname#2\endcsname}
+\def\SKV@ifdefined#1{\@nameuse{SKV@\ifdefined#11\else2\fi of2}}
+\def\SKV@unifdefined#1{\@nameuse{SKV@\ifdefined#12\else1\fi of2}}
+\def\SKV@ifcsname#1{\@nameuse{SKV@\ifcsname#1\endcsname1\else2\fi of2}}
+\def\SKV@unifcsname#1{\@nameuse{SKV@\ifcsname#1\endcsname2\else1\fi of2}}
+\def\SKV@iftest#1#2{\@nameuse{SKV@\@nameuse{#1}#21\else2\fi of2}}
+\begingroup
+\def\SKV@tempa{%
+  \def\SKV@nodocerr{%
+    \PackageError{skeyval}{'skeyval' package loaded before
+      \string\documentclass}{Load skeyval package after
+      \string\documentclass.}%
+    \endinput
+  }%
+  \def\SKV@tempb##1\@nil,{}%
+  \def\SKV@tempa##1,{%
+    \def\@currname{##1}%
+    \SKV@ifx\SKV@documentclass\SKV@undefined{%
+      \SKV@ifx\@currname\@nnil{}{%
+        \filename@parse\@currname
+        \SKV@unifx\filename@ext\@clsextension{}{%
+          \SKV@unifcsname{opt@\filename@area\filename@base.%
+            \filename@ext}{}{%
+            \edef\SKV@documentclass{\filename@area%
+              \filename@base.\filename@ext}%
+          }%
+        }%
+        \SKV@tempa
+      }%
+    }{%
+      \let\SKV@tempa\SKV@tempb\SKV@tempa
+    }%
+  }%
+  \SKV@ifx\@filelist\relax\SKV@nodocerr{%
+    \SKV@ifx\@filelist\@gobble\SKV@nodocerr{%
+      \expandafter\SKV@tempa\@filelist,\@nil,%
+    }%
+  }%
+  \SKV@ifx\SKV@documentclass\SKV@undefined\SKV@nodocerr\relax
+}
+\SKV@tempa\endgroup
 \def\SKV@ifdefinable#1{%
-  \edef\reserved@a{\expandafter\@gobble\string#1}%
-  \ifdefined#1%
-    \ifx#1\relax
-      \expandafter\expandafter\expandafter\@firstofone
-    \else
-      \expandafter\expandafter\expandafter\@notdefinable
-    \fi
-  \else
-    \edef\reserved@b{\expandafter\@carcube\reserved@a xxx\@nil}%
-    \ifx\reserved@b\@qend
-      \expandafter\expandafter\expandafter\@notdefinable
-    \else
-      \ifx\reserved@a\@qrelax
-        \expandafter\expandafter\expandafter\expandafter
-        \expandafter\expandafter\expandafter\@notdefinable
-      \else
-        \expandafter\expandafter\expandafter\expandafter
-        \expandafter\expandafter\expandafter\@firstofone
-      \fi
+  \begingroup\escapechar92\afterassignment\endgroup
+  \xdef\reserved@a{\expandafter\@gobble\string#1}%
+  \SKV@ifdefined#1{%
+    \SKV@ifx{#1}\relax\@firstofone\@notdefinable
+  }{%
+    \edef\reserved@b{\expandafter\SKV@carcube\reserved@a xxx\@nil}%
+    \SKV@ifx\reserved@b\@qend\@notdefinable
+      {\SKV@ifx\reserved@a\@qrelax\@notdefinable\@firstofone}%
+  }%
+}
+\newcommand*\@ifpackagecurrent[2]{%
+  \@nameuse{SKV@\SKV@iftest{ifnum}{\@threeexpafter\@parse@version
+  \csname ver@#1.\@pkgextension\endcsname//00\@nil
+  <\expandafter\@parse@version#2//00\@nil}{2}{1}of2}}
+\newcommand*\@ifpackagenotcurrent[2]{%
+  \@nameuse{SKV@\@ifpackagecurrent{#1}{#2}{2}{1}of2}}
+\@ifpackageloaded{xkeyval}{%
+  \@ifpackagecurrent{xkeyval}{2008/08/13}{}{%
+    \PackageError{skeyval}{%
+      Your loaded version of xkeyval package is not current
+    }{%
+      You need version 2.6a (or higher) of xkeyval package.
+    }%
+    \endinput
+  }%
+}{\RequirePackage{xkeyval}[2008/08/13]}
+\SKV@ifdefinable\SKV@ifdefinable@n\relax
+\protected\def\SKV@ifdefinable@n#1{%
+  \XKV@sp@deflist\SKV@tempa{#1}%
+  \XKV@for@o\SKV@tempa\SKV@tempa{%
+    \edef\resvd@a{\@threeexpafter\SKV@car
+      \expandafter\string\SKV@tempa\@nil}%
+    \ifx\resvd@a\@backslashchar
+      \PackageError{skeyval}{Backslash not allowed}{Backslash not
+        allowed in argument of '\string\SKV@ifdefinable@n'.}%
     \fi
-  \fi
+    \@threeexpafter\SKV@ifdefinable
+      \expandafter\csname\SKV@tempa\endcsname\relax
+  }%
+}
+\SKV@ifdefinable@n{SKV@def,SKV@@def,SKV@pdef,SKV@@pdef,
+  SKV@gdef,SKV@@gdef,SKV@pgdef,SKV@@pgdef,SKV@edef,
+  SKV@@edef,SKV@pedef,SKV@@pedef,SKV@redef,SKV@@redef,
+  SKV@csredef,SKV@predef,SKV@@predef,SKV@cspredef,
+  SKV@providedef,SKV@@providedef,SKV@providerobustdef,
+  SKV@@providerobustdef
+}
+\protected\def\SKV@def{\@star@or@long\SKV@@def}
+\def\SKV@@def#1{\SKV@ifdefinable#1{\l@ngrel@x\def#1}}
+\protected\def\SKV@gdef{\@star@or@long\SKV@@gdef}
+\def\SKV@@gdef#1{\SKV@ifdefinable#1{\l@ngrel@x\gdef#1}}
+\protected\def\SKV@edef{\@star@or@long\SKV@@edef}
+\def\SKV@@edef#1{\SKV@ifdefinable#1{\l@ngrel@x\edef#1}}
+\protected\def\SKV@pdef{\@star@or@long\SKV@@pdef}
+\def\SKV@@pdef#1{\SKV@ifdefinable#1{\l@ngrel@x\protected\def#1}}
+\protected\def\SKV@pgdef{\@star@or@long\SKV@@pgdef}
+\def\SKV@@pgdef#1{\SKV@ifdefinable#1{\l@ngrel@x\protected\gdef#1}}
+\protected\def\SKV@pedef{\@star@or@long\SKV@@pedef}
+\def\SKV@@pedef#1{\SKV@ifdefinable#1{\l@ngrel@x\protected\edef#1}}
+\protected\def\SKV@pxdef{\@star@or@long\SKV@@pxdef}
+\def\SKV@@pxdef#1{\SKV@ifdefinable#1{\l@ngrel@x\protected\xdef#1}}
+\protected\def\SKV@redef{\@star@or@long\SKV@@redef}
+\def\SKV@@redef#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@unifdefined{#1}{}{%
+    \SKV@ifx{#1}\relax{}{%
+      \SKV@vbsmsg{info}{Command '\string#1' redefined\on@line}%
+    }%
+  }%
+  \l@ngrel@x\def#1%
 }
-\SKV@ifdefinable\SKV@def{\protected\def\SKV@def{\@star@or@long\SKV@aux@def}}
-\SKV@ifdefinable\SKV@aux@def{%
-  \def\SKV@aux@def#1{\SKV@ifdefinable#1{\l@ngrel@x\def#1}}}
-\SKV@ifdefinable\SKV@gdef{\protected\def\SKV@gdef{\@star@or@long\SKV@aux@gdef}}
-\SKV@ifdefinable\SKV@aux@gdef{%
-  \def\SKV@aux@gdef#1{\SKV@ifdefinable#1{\global\l@ngrel@x\def#1}}}
-\SKV@ifdefinable\SKV@edef{\protected\def\SKV@edef{\@star@or@long\SKV@aux@edef}}
-\SKV@ifdefinable\SKV@aux@edef{%
-  \def\SKV@aux@edef#1{\SKV@ifdefinable#1{\l@ngrel@x\edef#1}}}
-\SKV@ifdefinable\SKV@pdef{\protected\def\SKV@pdef{\@star@or@long\SKV@aux@pdef}}
-\SKV@ifdefinable\SKV@aux@pdef{%
-  \def\SKV@aux@pdef#1{\SKV@ifdefinable#1{\protected\l@ngrel@x\def#1}}}
-\SKV@ifdefinable\SKV@pedef{\protected\def\SKV@pedef{\@star@or@long\SKV@aux@pedef}}
-\SKV@ifdefinable\SKV@aux@pedef{%
-  \def\SKV@aux@pedef#1{\SKV@ifdefinable#1{\protected\l@ngrel@x\edef#1}}}
-\SKV@pdef\SKV@defined@err#1{\def\reserved@a{#1}\@notdefinable}
-\SKV@def\SKV@for@ifdefinable#1{%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b#1\SKV@tempa{%
-    \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-    \if\expandafter\expandafter\expandafter\SKV@car\expandafter
-      \string\SKV@tempa\SKV@nil\@backslashchar
-      \SKV@err{Backslash not allowed}\@ehc
-    \fi
-    \SKV@ifnameundef\SKV@tempa{}{\SKV@defined@err\SKV@tempa}%
+\protected\def\SKV@csredef{\SKV@aftercs\SKV@redef}
+\protected\def\SKV@predef{\@star@or@long\SKV@@predef}
+\def\SKV@@predef#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@unifdefined{#1}{}{%
+    \SKV@ifx{#1}\relax{}{%
+      \SKV@vbsmsg{info}{Command '\string#1' redefined\on@line}%
+    }%
   }%
+  \l@ngrel@x\protected\def#1%
+}
+\protected\def\SKV@cspredef{\SKV@aftercs\SKV@predef}
+\SKV@def\SKV@vbsmsg#1#2{%
+  \begingroup
+  \def\@i{info}\def\@ii{warn}\def\@iii{#1}%
+  \csname SKV@\ifSKV@verbose1\else2\fi of2\endcsname
+  {\SKV@ifx\@i\@iii
+      {\SKV@info{#2}}%
+        {\SKV@ifx\@ii\@iii{\SKV@warn{#2}}{}}%
+  }{}%
+  \endgroup
 }
+\define@boolkeys[KV]{skeyval@i}[SKV@]{st,pl,ask,sk,loc,uv}[true]
+\setkeys[KV]{skeyval@i}{st,pl,ask,sk,loc,uv}
+\define@boolkey+[KV]{skeyval}[SKV@]{verbose}[true]{}{%
+  \SKV@inputerr{#1}{verbose}%
+}
+\setkeys[KV]{skeyval}{verbose=false}
 \SKV@pdef\SKV@info#1{\PackageInfo{skeyval}{#1\@gobble}}
 \SKV@pdef\SKV@warn#1{\PackageWarningNoLine{skeyval}{#1}}
 \SKV@pdef\SKV@err#1#2{\PackageError{skeyval}{#1}{#2}}
-\SKV@def*\SKV@nil{\noexpand\SKV@nil}
-\SKV@def*\SKV@nnil{\SKV@nil}
-\SKV@def\SKV@car#1#2\SKV@nil{#1}
-\gdef\@notprerr{\SKV@err{You've issued a preamble command here}%
-  {Take command to preamble.}}
+\SKV@def*\SKV@MB{\MessageBreak}
 \SKV@pdef\SKV@afterfi#1\fi{\fi#1}
 \SKV@pdef\SKV@afterelsefi#1\else#2\fi{\fi#1}
-\SKV@def\SKV@aftercsname#1#2{\expandafter#1\csname#2\endcsname}
-\SKV@def\SKV@findescape#1{%
-  \begingroup\escapechar92 \expandafter\endgroup
-  \if\expandafter\SKV@car\string#1\SKV@nil\@backslashchar
-    \expandafter\@firstoftwo
+\SKV@pdef\SKV@afterfifi#1\fi#2\fi{\fi#2\fi#1}
+\SKV@def*\SKV@state#1#2#3{%
+  \ifcase#1\relax
+    \def\SKV@ste{XKV@prefix,XKV@fams,XKV@tkey,XKV@na,ifXKV@st,%
+      ifXKV@pl,ifXKV@knf,CurrentOption,ifSKV@sk}%
+    \SKV@ifempty{#3}{\advance\XKV@depth\@ne}{}%
+  \or
+    \def\SKV@ste{ifSKV@st,ifSKV@pl,ifSKV@ask}%
+    \SKV@ifempty{#3}{\advance\SKV@depth\@ne}{}%
   \else
-    \expandafter\@secondoftwo
+    \SKV@err{Unknown state identifier}%
+      {I expected '\string#1' to be number 0 or 1.}%
+  \fi
+  \XKV@for@o\SKV@ste\SKV@ste{%
+    \SKV@aftercs\let{\SKV@ste#2\SKV@aftercs}{\SKV@ste#3}%
+  }%
+  \ifcase#1\relax
+    \SKV@ifempty{#2}{\advance\XKV@depth\m@ne}{}%
+  \or
+    \SKV@ifempty{#2}{\advance\SKV@depth\m@ne}{}%
   \fi
 }
-\SKV@def*\SKV@expandox#1{\unexpanded\expandafter{#1}}
-\SKV@def*\SKV@expandnameox#1{\SKV@aftercsname\SKV@expandox{#1}}
-\SKV@def*\SKV@expandtx#1{\unexpanded\expandafter\expandafter\expandafter{#1}}
-\SKV@def*\SKV@expandnametx#1{\SKV@aftercsname\SKV@expandtx{#1}}
-\SKV@def*\SKV@noexpandcs#1{\SKV@aftercsname\noexpand{#1}}
-\SKV@pdef\SKV@undef#1{\let#1\SKV@undefined}
-\SKV@pdef\SKV@gundef#1{\global\let#1\SKV@undefined}
-\SKV@pdef\SKV@nameundef#1{\SKV@aftercsname\let{#1}\SKV@undefined}
-\SKV@pdef\SKV@namegundef#1{\global\SKV@aftercsname\let{#1}\SKV@undefined}
-\SKV@def\SKV@ifdef#1{%
-  \ifdefined#1%
-    \expandafter\@firstoftwo
+\SKV@def*\XKV@savstate{\SKV@state{0}{@\romannumeral\XKV@depth}{}}
+\SKV@def*\XKV@resstate{\SKV@state{0}{}{@\romannumeral\XKV@depth}}
+\SKV@def*\SKV@savstate{\SKV@state{1}{@\romannumeral\SKV@depth}{}}
+\SKV@def*\SKV@resstate{\SKV@state{1}{}{@\romannumeral\SKV@depth}}
+\def\XKV@srstate#1#2{\SKV@state{0}{#1}{#2}}
+\def\SKV@scantoks#1#2{%
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    \unexpanded{%
+      #1\everyeof{\noexpand}\endlinechar\m@ne
+      \makeatletter\scantokens
+    }{#2}%
+    \catcode`\noexpand\@=\the\catcode`\@\relax
+    \everyeof{\the\everyeof}%
+    \noexpand\endlinechar\the\endlinechar\relax
+  }%
+  \SKV@tempa
+}
+\SKV@def\SKV@newcs#1#2{%
+  \SKV@ifcsname{#2}{%
+    \SKV@csifx{#2}\relax{}{\def\reserved@a{#2}\@notdefinable}%
+  }{\SKV@aftercs{#1}{#2}}%
+}
+\SKV@pdef*\SKV@csdef{\SKV@savstate\SKV@t@st@pta\SKV@@csdef}
+\SKV@def*\SKV@@csdef#1{%
+  \ifSKV@pl
+    \let\SKV@n@xt\SKV@newcs
   \else
-    \expandafter\@secondoftwo
+    \let\SKV@n@xt\SKV@aftercs
   \fi
+  \SKV@resstate\SKV@n@xt\def{#1}%
 }
-\SKV@def\SKV@ifundef#1{%
-  \ifdefined#1%
-    \ifx#1\relax
-      \expandafter\expandafter\expandafter\@firstoftwo
-    \else
-      \expandafter\expandafter\expandafter\@secondoftwo
-    \fi
+\SKV@pdef*\SKV@csgdef{\SKV@savstate\SKV@t@st@pta\SKV@@csgdef}
+\SKV@def*\SKV@@csgdef#1{%
+  \ifSKV@pl
+    \let\SKV@n@xt\SKV@newcs
   \else
-    \expandafter\@firstoftwo
+    \let\SKV@n@xt\SKV@aftercs
   \fi
+  \SKV@resstate\SKV@n@xt\gdef{#1}%
 }
-\SKV@def*\SKV@ifnamedef#1{%
-  \ifcsname#1\endcsname
-    \expandafter\@firstoftwo
+\SKV@pdef*\SKV@csedef{\SKV@savstate\SKV@t@st@pta\SKV@@csedef}
+\SKV@def*\SKV@@csedef#1{%
+  \ifSKV@pl
+    \let\SKV@n@xt\SKV@newcs
   \else
-    \expandafter\@secondoftwo
+    \let\SKV@n@xt\SKV@aftercs
   \fi
+  \SKV@resstate\SKV@n@xt\edef{#1}%
 }
-\SKV@def*\SKV@ifnameundef#1{%
-  \ifcsname#1\endcsname
-    \expandafter\ifx\csname#1\endcsname\relax
-      \expandafter\expandafter\expandafter\@firstoftwo
-    \else
-      \expandafter\expandafter\expandafter\@secondoftwo
-    \fi
+\SKV@pdef*\SKV@csxdef{\SKV@savstate\SKV@t@st@pta\SKV@@csxdef}
+\SKV@def*\SKV@@csxdef#1{%
+  \ifSKV@pl
+    \let\SKV@n@xt\SKV@newcs
   \else
-    \expandafter\@firstoftwo
+    \let\SKV@n@xt\SKV@aftercs
   \fi
+  \SKV@resstate\SKV@n@xt\xdef{#1}%
 }
-\SKV@def\SKV@remparser#1#2{%
-  \def\tok@i{#1}\edef\tok@ii{#1#2}%
-  \ifx#2\@empty\else
-    \def\SKV@remove#1##1\SKV@nil{\def\tok@ii{##1}}%
-    \SKV@r@move\let#2\tok@ii
-  \fi
+\SKV@def*\SKV@csuse#1{\SKV@ifcsname{#1}{\@nameuse{#1}}{}}
+\SKV@pdef\SKV@expargs#1#2#3#4\@nil{%
+  \begingroup
+  \protected@edef\SKV@tempa{\endgroup
+    \ifcase#1\relax
+      \unexpanded{#2}{#3}%
+    \or
+      \unexpanded{#2#3}{#4}%
+    \or
+      \unexpanded{#2}{#3}{#4}%
+    \or
+      \unexpanded{#2}#3\unexpanded{#4}%
+    \else
+      \SKV@err{Unknown expansion type '\string#1' for
+        \string\SKV@expargs}{I expected your first
+          argument '\string#1' to be between 0 and 3.}%
+    \fi
+  }%
+  \SKV@tempa
 }
-\SKV@def*\SKV@r@move{\expandafter\SKV@rem@ve\tok@ii\SKV@nil}
-\SKV@def*\SKV@rem@ve{\futurelet\@temptoks\SKV@remo@e}
-\SKV@def*\SKV@remo@e#1\SKV@nil{%
-  \if\@temptoks\tok@i
-    \expandafter\SKV@remove\tok@ii\SKV@nil
-    \SKV@r@move
-  \fi
+\SKV@def*\SKV@findescape#1{%
+  \begingroup\escapechar92\relax
+  \edef\resvd@a{\expandafter\SKV@car\string#1\@nil}%
+  \expandafter\aftergroup\csname SKV@%
+  \SKV@ifx\resvd@a\@backslashchar{1}{2}of2\endcsname
+  \endgroup
+}
+\SKV@def*\SKV@ensurescape#1{%
+  \SKV@findescape{#1}{}%
+    {\SKV@err{Backslash required in '\string#1'}%
+      {I expected a backslash to be the leading\SKV@MB
+        character in your argument '\string#1'.}}%
 }
-\SKV@def\SKV@apptomacro@a#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@def*\SKV@ensurenoscape#1{%
+  \SKV@findescape{#1}%
+    {\SKV@err{Backslash not allowed in '\string#1'}%
+      {I didn't expect a backslash to be the leading\SKV@MB
+        character in your argument '\string#1'.}}{}%
+}
+\SKV@pdef\SKV@ifnextchar#1#2#3{%
+  \let\SKV@nxc#1\def\SKV@nxa{#2}\def\SKV@nxb{#3}%
+  \futurelet\@temptoks\SKV@ifnextch@r
+}
+\SKV@def*\SKV@ifnextch@r{%
+  \ifx\@temptoks\SKV@nxc\let\SKV@nxb\SKV@nxa\fi\SKV@nxb
+}
+\SKV@pdef\SKV@ifstar#1#2{%
+  \SKV@ifnextchar*{\begingroup
+    \def\SKV@tempa*{\endgroup #1}\SKV@tempa}{#2}%
+}
+\SKV@pdef\SKV@ifplus#1#2{%
+  \SKV@ifnextchar+{\begingroup
+    \def\SKV@tempa+{\endgroup #1}\SKV@tempa}{#2}%
+}
+\SKV@pdef\SKV@ifask#1#2{%
+  \SKV@ifnextchar?{\begingroup
+    \def\SKV@tempa?{\endgroup #1}\SKV@tempa}{#2}%
+}
+\SKV@pdef\SKV@ifbrack#1#2{\SKV@ifnextchar[{#1}{#2}}
+\SKV@pdef\SKV@ifparen#1#2{\SKV@ifnextchar({#1}{#2}}
+\SKV@pdef*\SKV@testopt#1#2{\SKV@ifnextchar[{#1}{#1[{#2}]}}
+\SKV@pdef*\SKV@testopta#1{\SKV@t@stopta{\SKV@t@st@pta{#1}}}
+\SKV@pdef*\SKV@t@stopta#1{\SKV@ifstar{\SKV@sttrue#1}{\SKV@stfalse#1}}
+\SKV@pdef*\SKV@t@st@pta#1{\SKV@ifplus{\SKV@pltrue#1}{\SKV@plfalse#1}}
+\SKV@pdef*\SKV@t@st@p@a#1{\SKV@ifask{\SKV@asktrue#1}{\SKV@askfalse#1}}
+\SKV@pdef*\SKV@testoptb#1{\SKV@t@stopta{\SKV@t@st@pta{\SKV@t@st@p@a{#1}}}}
+\SKV@pdef*\SKV@t@stoptb#1{\SKV@t@stopta{\SKV@t@st@pta{#1}}}
+\SKV@pdef*\SKV@testoptc#1{\SKV@t@st@pta{\SKV@t@st@p@a{#1}}}
+\SKV@pdef*\SKV@testoptd#1{\SKV@t@stopta{\SKV@testopt#1{,}}}
+\SKV@pdef*\SKV@testopte#1{\SKV@testoptb{\SKV@testopt#1{,}}}
+\SKV@pdef*\SKV@t@stopte#1{\SKV@t@stoptb{\SKV@testopt#1{,}}}
+\SKV@pdef*\SKV@testoptf#1{\SKV@testoptc{\SKV@testopt#1{,}}}
+\SKV@def*\SKV@Test@pt#1{\@nameuse{SKV@\SKV@ifempty{#1}{1}{2}of2}}
+\SKV@def*\SKV@TestOpt#1#2#3{\SKV@@TestOpt#1&[&{#2#1}{#2[{#3}]{#1}}}
+\SKV@def*\SKV@@TestOpt#1[#2&#3#{\SKV@Test@pt{#1#2}}
+\SKV@def*\SKV@IfStar#1#2#3{\SKV@@IfStar#1&*&{#2}{#3{#1}}}
+\SKV@def*\SKV@@IfStar#1*#2&#3#{\SKV@Test@pt{#1#2}}
+\SKV@def*\SKV@IfPlus#1#2#3{\SKV@@IfPlus#1&+&{#2}{#3{#1}}}
+\SKV@def*\SKV@@IfPlus#1+#2&#3#{\SKV@Test@pt{#1#2}}
+\SKV@def*\SKV@IfAsk#1#2#3{\SKV@@IfAsk#1&?&{#2}{#3{#1}}}
+\SKV@def*\SKV@@IfAsk#1?#2&#3#{\SKV@Test@pt{#1#2}}
+\SKV@pdef*\NewWrites{\SKV@testopt\SKV@NewWrites{}}
+\SKV@pdef*\SKV@NewWrites[#1]#2{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{#1\SKV@tempa}{%
+      \@nameuse{newwrite\SKV@aftercs}{#1\SKV@tempa}%
+    }%
   }%
-  \SKV@ifundef{#1}{%
-    \edef#1{\unexpanded{#2}}%
-  }{%
-    \edef#1{\SKV@expandox#1\unexpanded{#2}}%
+}
+\SKV@pdef*\NewIfs{\SKV@testopt\SKV@NewIfs{}}
+\SKV@pdef*\SKV@NewIfs[#1]#2{\SKV@testopt{\SKV@NewIf@[#1]{#2}}{false}}
+\SKV@pdef*\SKV@NewIf@[#1]#2[#3]{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{if#1\SKV@tempa}{%
+     \@nameuse{newif\SKV@aftercs}{if#1\SKV@tempa}%
+     \@nameuse{#1\SKV@tempa#3}%
+    }%
   }%
 }
-\SKV@def\SKV@apptomacro@b#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@pdef*\NewTogs{\SKV@testopt\SKV@NewTogs{}}
+\SKV@pdef*\SKV@NewTogs[#1]#2{\SKV@testopt{\SKV@NewT@gs[#1]{#2}}{false}}
+\SKV@pdef*\SKV@NewT@gs[#1]#2[#3]{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \edef\SKV@tempa{#1\SKV@tempa}%
+    \SKV@expnext\newtog\SKV@tempa
+    \@nameuse{tog#3\SKV@expnext}\SKV@tempa
   }%
-  \SKV@ifundef{#1}{%
-    \edef#1{\SKV@expandox{#2}}%
-  }{%
-    \xdef#1{\SKV@expandox#1\SKV@expandox{#2}}%
+}
+\SKV@pdef*\NewToks{\SKV@testopt\SKV@NewToks{}}
+\SKV@pdef*\SKV@NewToks[#1]#2{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{#1\SKV@tempa}{%
+      \@nameuse{newtoks\SKV@aftercs}{#1\SKV@tempa}%
+    }%
   }%
 }
-\SKV@def\SKV@preptomacro@a#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@pdef*\NewCounts{\SKV@testopt\SKV@NewCounts{}}
+\SKV@pdef*\SKV@NewCounts[#1]#2{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{#1\SKV@tempa}{%
+      \@nameuse{newcount\SKV@aftercs}{#1\SKV@tempa}%
+    }%
   }%
-  \SKV@ifundef{#1}{%
-    \edef#1{\unexpanded{#2}}%
-  }{%
-    \edef#1{\unexpanded{#2}\SKV@expandox#1}%
+}
+\SKV@pdef*\NewDimens{\SKV@testopt\SKV@NewDimens{}}
+\SKV@pdef*\SKV@NewDimens[#1]#2{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{#1\SKV@tempa}{%
+      \@nameuse{newdimen\SKV@aftercs}{#1\SKV@tempa}%
+    }%
   }%
 }
-\SKV@def\SKV@preptomacro@b#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@pdef*\NewBoxes{\SKV@testopt\SKV@NewBoxes{}}
+\SKV@pdef*\SKV@NewBoxes[#1]#2{%
+  \SKV@for[,]{#2}\SKV@tempa{%
+    \SKV@expnext\SKV@ensurenoscape\SKV@tempa
+    \SKV@aftercs\SKV@ifdefinable{#1\SKV@tempa}{%
+      \@nameuse{newbox\SKV@aftercs}{#1\SKV@tempa}%
+    }%
   }%
-  \SKV@ifundef{#1}{%
-    \edef#1{\SKV@expandox{#2}}%
+}
+\SKV@def\SKV@expnext#1#2{%
+  \SKV@ifblank{#1}{%
+    \SKV@err{Arguments of '\string\SKV@expnext' can't be empty}\@ehc
   }{%
-    \edef#1{\SKV@expandox{#2}\SKV@expandox#1}%
+    \SKV@ifblank{#2}{%
+      \SKV@err{Arguments of '\string\SKV@expnext' can't be empty}\@ehc
+    }{%
+      \SKV@iftest{if}{@\detokenize\expandafter{\SKV@cdr#1\@nil}@}{%
+        \expandafter#1\expandafter{#2}%
+      }{%
+        \SKV@err{Invalid arguments '\string#1' for
+          '\string\SKV@expnext'\SKV@MB}\@ehc
+      }%
+    }%
   }%
 }
-\SKV@def\SKV@gapptomacro@a#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
-  }%
-  \SKV@ifundef{#1}{%
-    \xdef#1{\unexpanded{#2}}%
-  }{%
-    \xdef#1{\SKV@expandox#1\unexpanded{#2}}%
+\SKV@pdef*\SKV@DelayedAfterPackageEnd#1{%
+  \AtEndOfPackage{\SKV@AfterPackageEnd{#1}}}
+\SKV@def\DeclarePackageCommand#1#2{%
+  \SKV@ensurescape{#2}%
+  \SKV@ifdefined#2{%
+    \edef\resvd@a{\expandafter\@gobble\string#2}%
+    \SKV@aftercs\let{Saved\resvd@a}#2%
+    \edef\resvd@a##1{%
+      \SKV@DelayedAfterPackageEnd{##1Saved\resvd@a\noexpand\endcsname}%
+    }%
+    \resvd@a{\expandafter\let\expandafter#2\csname}%
+    \let\resvd@a\relax
+  }{\SKV@DelayedAfterPackageEnd{\SKV@gundef#2}}%
+  #1#2%
+}
+\DeclarePackageCommand{\protected\def}\@namegdef{\SKV@aftercs\gdef}
+\DeclarePackageCommand{\protected\def}\@nameedef{\SKV@aftercs\edef}
+\DeclarePackageCommand{\protected\def}\@namexdef{\SKV@aftercs\xdef}
+\SKV@pdef*\SKV@ifnew{\SKV@savstate\SKV@t@stopte\SKV@@ifnew}
+\SKV@def*\SKV@@ifnew[#1]#2{%
+  \ifSKV@st
+    \ifSKV@pl
+      \def\SKV@ndl{\SKV@for*[#1]#2}%
+    \else
+      \def\SKV@ndl{\SKV@tfor*#2}%
+    \fi
+  \else
+    \ifSKV@pl
+      \def\SKV@ndl{\SKV@for[#1]{#2}}%
+    \else
+      \def\SKV@ndl{\SKV@tfor{#2}}%
+    \fi
+  \fi
+  \SKV@ndl\SKV@ndl{%
+    \ifSKV@pl
+      \SKV@despace\SKV@ndl
+      \SKV@expargs{1}\SKV@aftercs
+        \SKV@ifdefinable{\SKV@ndl}\@nil\relax
+    \else
+      \expandafter\SKV@ifdefinable\SKV@ndl\relax
+    \fi
   }%
+  \SKV@resstate
+}
+\let\SKV@no\z@
+\SKV@pdef*\SKV@aftergroup{%
+  \SKV@ifstar{\SKV@aft@rgroup\@firstofone}{\SKV@aft@rgroup\unexpanded}%
 }
-\SKV@def\SKV@gapptomacro@b#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@def\SKV@aft@rgroup#1#2{%
+  \edef\SKV@no{\the\numexpr\SKV@no+1}%
+  \SKV@aftercs\xdef{SKV@aft@rgr@up\SKV@no}{%
+    \SKV@csgundef{SKV@aft@rgr@up\SKV@no}%
+    #1{#2}%
   }%
-  \SKV@ifundef{#1}{%
-    \xdef#1{\SKV@expandox{#2}}%
-  }{%
-    \xdef#1{\SKV@expandox#1\SKV@expandox{#2}}%
+  \SKV@aftercs\aftergroup{SKV@aft@rgr@up\SKV@no}%
+}
+\SKV@pdef*\SKV@afterassignment{%
+  \SKV@ifstar{\SKV@aft@rassignment\@firstofone}%
+    {\SKV@aft@rassignment\unexpanded}%
+}
+\SKV@def\SKV@aft@rassignment#1#2{%
+  \begingroup
+  \edef\SKV@no{\the\numexpr\SKV@no+1}%
+  \SKV@aftercs\xdef{SKV@aft@rassignm@nt\SKV@no}{%
+    \SKV@csgundef{SKV@aft@rassignm@nt\SKV@no}%
+    #1{#2}%
   }%
+  \expandafter\endgroup\expandafter\afterassignment
+    \csname SKV@aft@rassignm@nt\SKV@no\endcsname
 }
-\SKV@def\SKV@gpreptomacro@a#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@def*\SKV@trailead#1#2{%
+  \edef\SKV@trail{\the\SKV@toks}%
+  \SKV@toks\expandafter{\romannumeral-`\q\SKV@tr@ilead\noexpand#1& &}%
+  \edef#2{\the\SKV@toks}%
+  \SKV@toks\expandafter{\SKV@trail}%
+  \SKV@undef\SKV@trail
+}
+\SKV@def*\SKV@tr@ilead#1 &{\SKV@tr@ile@d#1&}
+\SKV@def*\SKV@tr@ile@d#1&#2{\romannumeral-`\q#1}
+\SKV@def*\SKV@expox#1{\unexpanded\expandafter{#1}}
+\SKV@def*\SKV@expcsox#1{\SKV@aftercs\SKV@expox{#1}}
+\SKV@def*\SKV@exptx#1{\unexpanded\@threeexpafter{#1}}
+\SKV@def*\SKV@expcstx#1{\SKV@aftercs\SKV@exptx{#1}}
+\SKV@pdef*\SKV@undef#1{\let#1\SKV@undefined}
+\SKV@pdef\SKV@gundef{\global\SKV@undef}
+\SKV@pdef*\SKV@csundef#1{\SKV@aftercs\SKV@undef{#1}}
+\SKV@pdef*\SKV@csgundef{\global\SKV@csundef}
+\SKV@pdef*\SKV@undeflt#1#2{%
+  \SKV@ifempty{#1}{\let\glob@lrel@x\relax}{\let\glob@lrel@x\global}%
+  \SKV@for[,]{#2}\SKV@resvd{%
+    \SKV@expnext\SKV@ensurescape\SKV@resvd
+    \glob@lrel@x\expandafter\SKV@undef\SKV@resvd
+  }%
+}
+\SKV@pdef*\SKV@Undef{\SKV@savstate\SKV@testopte\SKV@@Undef}
+\SKV@def*\SKV@@Undef[#1]#2{%
+  \ifSKV@st
+    \ifSKV@pl
+      \def\SKV@ndl{\SKV@for*[#1]#2}%
+    \else
+      \def\SKV@ndl{\SKV@tfor*#2}%
+    \fi
+  \else
+    \ifSKV@pl
+      \def\SKV@ndl{\SKV@for[#1]{#2}}%
+    \else
+      \def\SKV@ndl{\SKV@tfor{#2}}%
+    \fi
+  \fi
+  \SKV@ndl\SKV@ndl{%
+    \ifSKV@pl
+      \SKV@despace\SKV@ndl
+      \ifSKV@ask\expandafter\global\fi
+      \@threeexpafter\let
+      \expandafter\csname\SKV@ndl\endcsname\SKV@undefined
+    \else
+      \ifSKV@ask\expandafter\global\fi
+      \expandafter\let\SKV@ndl\SKV@undefined
+    \fi
   }%
-  \SKV@ifundef{#1}{%
-    \xdef#1{\unexpanded{#2}}%
+  \SKV@resstate
+}
+\SKV@def*\SKV@ifdef#1{%
+  \SKV@ifdefined{#1}%
+    {\@nameuse{SKV@\SKV@ifx{#1}\relax{2}{1}of2}}\@secondoftwo
+}
+\SKV@def*\SKV@ifundef#1{\@nameuse{SKV@\SKV@ifdef{#1}{2}{1}of2}}
+\SKV@def*\SKV@ifcsdef#1{%
+  \SKV@ifcsname{#1}%
+    {\@nameuse{SKV@\expandafter\SKV@ifx\csname#1\endcsname
+      \relax{2}{1}of2}}\@secondoftwo
+}
+\SKV@def*\SKV@ifcsundef#1{\@nameuse{SKV@\SKV@ifcsdef{#1}{2}{1}of2}}
+\SKV@pdef*\SKV@providedef{\@star@or@long\SKV@@providedef}
+\SKV@def\SKV@@providedef#1{%
+  \edef\SKV@prov@d{\expandafter\@gobble\string#1}%
+  \SKV@aftercs\let{SKV@test@\SKV@prov@d}\SKV@undefined
+  \SKV@ifdef#1{%
+    \SKV@vbsmsg{info}{Command '\string#1' already defined:\SKV@MB
+      Not redefined\on@line}%
+    \SKV@afterassignment{\SKV@gundef\SKV@pr@vid}%
+    \def\SKV@pr@vid
   }{%
-    \xdef#1{\unexpanded{#2}\SKV@expandox#1}%
+    \SKV@afterassignment{%
+      \SKV@aftercs\edef{SKV@test@\SKV@prov@d}%
+        {\expandafter\strip@prefix\meaning#1}%
+    }%
+    \l@ngrel@x\def#1%
   }%
 }
-\SKV@def\SKV@gpreptomacro@b#1#2{%
-  \SKV@findescape{#1}{}{%
-    \SKV@err{Bad argument '\string#1'}{Backslash required in '\string#1'.}%
+\SKV@pdef*\SKV@providerobustdef{\@star@or@long\SKV@@providerobustdef}
+\SKV@def\SKV@@providerobustdef#1{%
+  \edef\SKV@prov@d{\expandafter\@gobble\string#1}%
+  \SKV@aftercs\let{SKV@test@\SKV@prov@d}\SKV@undefined
+  \SKV@ifdef#1{%
+    \SKV@vbsmsg{info}{Command '\string#1' already defined:\SKV@MB
+      Not redefined\on@line}%
+    \SKV@afterassignment{\SKV@gundef\SKV@pr@vid}%
+    \def\SKV@pr@vid
+  }{%
+    \SKV@afterassignment{%
+      \SKV@aftercs\edef{SKV@test@\SKV@prov@d}%
+        {\expandafter\strip@prefix\meaning#1}%
+    }%
+    \l@ngrel@x\protected\def#1%
   }%
+}
+\SKV@def\TestProvidedCommand#1{%
+  \begingroup
+  \SKV@ifmacro#1{%
+    \edef\SKV@resvd@a{\expandafter\@gobble\string#1}%
+    \edef\SKV@resvd@b{\expandafter\strip@prefix\meaning#1}%
+    \expandafter\aftergroup\csname SKV@\expandafter
+      \ifx\expandafter\SKV@resvd@b
+      \csname SKV@test@\SKV@resvd@a\endcsname
+      1\else2\fi of2\endcsname
+  }{\aftergroup\@secondoftwo}%
+  \endgroup
+}
+\SKV@pdef*\SKV@newdef{\SKV@def}
+\SKV@providerobustdef*\newdef{\SKV@def}
+\SKV@pdef*\SKV@robustdef{\SKV@pdef}
+\SKV@providerobustdef*\robustdef{\SKV@pdef}
+\SKV@providerobustdef*\providedef{\SKV@providedef}
+\SKV@providerobustdef*\providerobustdef{\SKV@providerobustdef}
+\SKV@def\SKV@ifmacro#1{%
+  \begingroup
+  \edef\SKV@ifmacro##1{\def##1####1\detokenize{macro}:####2&}%
+  \SKV@ifmacro\@ifmacro{\expandafter\aftergroup
+    \csname SKV@\SKV@ifblank{##2}{2}{1}of2\endcsname}%
+  \edef\SKV@ifmacro##1{##1\detokenize{macro}:&}%
+  \SKV@ifmacro{\expandafter\@ifmacro\meaning#1}%
+  \endgroup
+}
+\SKV@def\SKV@ifnotmacro#1{\SKV@ifmacro{#1}\@secondoftwo\@firstoftwo}
+\SKV@def\SKV@ifparamacro#1{%
+  \begingroup
+  \edef\SKV@ifparamacro##1{%
+    \def##1####1\detokenize{macro}:####2->####3&}%
+  \SKV@ifparamacro\@ifparam{\expandafter\aftergroup
+    \csname SKV@\SKV@ifblank{##2}{2}{1}of2\endcsname}%
+  \edef\SKV@ifparamacro##1{##1\detokenize{macro}:->&}%
+  \SKV@ifparamacro{\expandafter\@ifparam\meaning#1}%
+  \endgroup
+}
+\SKV@def*\SKV@ifrelax#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@ifdefined{#1}%
+    {\@nameuse{SKV@\SKV@ifx{#1}\relax{1}{2}of2}}\@secondoftwo
+}
+\SKV@def*\SKV@ifcsrelax#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsname{#1}%
+    {\@nameuse{SKV@\expandafter\SKV@ifx\csname#1\endcsname
+      \relax{1}{2}of2}}\@secondoftwo
+}
+\SKV@def*\SKV@ifdefax#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@ifdefined{#1}%
+    {\@nameuse{SKV@\SKV@ifx{#1}\relax{2}{1}of3}}\@thirdofthree
+}
+\SKV@def*\SKV@ifcsdefax#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsname{#1}%
+    {\@nameuse{SKV@\expandafter\SKV@ifx\csname#1\endcsname
+      \relax{2}{1}of3}}\@thirdofthree
+}
+\SKV@def*\SKV@despace#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@expnext\SKV@trailead{#1}#1%
+}
+\SKV@def\SKV@detokdespace#1#2{\edef#2{\detokenize{#1}}\SKV@despace#2}
+\SKV@def\SKV@ifblank#1{\SKV@ifbl@nk#1&&\@secondoftwo\@firstoftwo:}
+\SKV@def\SKV@ifbl@nk#1#2&#3#4#5:{#4}
+\SKV@def\SKV@ifnotblank#1{\SKV@ifbl@nk#1&&\@firstoftwo\@secondoftwo:}
+\SKV@def\SKV@oifblank#1{\expandafter\SKV@ifblank\expandafter{#1}}
+\SKV@def\SKV@xifblank#1{\SKV@expargs{0}\SKV@ifblank{#1}\@nil}
+\SKV@def\SKV@ifstrequal#1#2{%
+  \begingroup
+  \SKV@detokdespace{#1}\resvd@a\SKV@detokdespace{#2}\resvd@b
+  \expandafter\aftergroup
+  \csname SKV@\SKV@ifx\resvd@a\resvd@b{1}{2}of2\endcsname
+  \endgroup
+}
+\SKV@def\SKV@ifstrnotequal#1#2{\SKV@ifstrequal{#1}{#2}\@secondoftwo\@firstoftwo}
+\SKV@def\SKV@oifstrequal#1#2{%
+  \@expandtwoargs\SKV@ifstrequal{\SKV@expox{#1}}{\SKV@expox{#2}}}
+\SKV@def\SKV@xifstrequal#1#2{\@expandtwoargs\SKV@ifstrequal{#1}{#2}}
+\SKV@def\SKV@ifempty#1{\@nameuse{SKV@\ifcat$\detokenize{#1}$1\else2\fi of2}}
+\SKV@def\SKV@ifnotempty#1{\@nameuse{SKV@\SKV@ifempty{#1}{2}{1}of2}}
+\SKV@def\SKV@oifempty#1{\SKV@expnext\SKV@ifempty{#1}}
+\SKV@def\SKV@xifempty#1{\SKV@expargs{0}\SKV@ifempty{#1}\@nil}
+\SKV@def*\SKV@remparser{\SKV@testopt\SKV@remp@rser{,}}
+\SKV@def\SKV@remp@rser[#1]#2{%
+  \begingroup
+  \ifx#2\@empty\else
+    \edef#2{#1\SKV@expox{#2}}%
+    \def\SKV@tempa#1##1\@nil{%
+      \gdef#2{##1}\futurelet\@temptoks\SKV@t@mp##1\@nil
+    }%
+    \def\SKV@t@mp##1\@nil{%
+      \ifx\@temptoks\@sptoken
+        \SKV@expnext\SKV@trailead{#2}#2%
+        \expandafter\SKV@tempa\expandafter#1#2\@nil
+      \else
+        \if#1\@temptoks\expandafter\SKV@tempa#2\@nil\fi
+      \fi
+    }%
+    \expandafter\SKV@tempa#2\@nil
+  \fi
+  \endgroup
+}
+\SKV@pdef*\SKV@appto{\SKV@savstate\SKV@testoptb\SKV@@appto}
+\SKV@def\SKV@@appto#1#2{%
+  \ifSKV@st
+    \let\@unexp@expox\SKV@expox
+  \else
+    \let\@unexp@expox\unexpanded
+  \fi
+  \SKV@ap@to{#1}{#2}%
+  \SKV@resstate
+}
+\SKV@def*\SKV@ap@to#1#2{%
+  \ifSKV@pl
+    \ifSKV@ask
+      \let\SKV@n@xt\SKV@csxdef
+    \else
+      \let\SKV@n@xt\SKV@csedef
+    \fi
+    \SKV@ifcsundef{#1}{%
+      \SKV@n@xt{#1}{\@unexp@expox{#2}}%
+    }{%
+      \SKV@n@xt{#1}{\SKV@expcsox{#1}\@unexp@expox{#2}}%
+    }%
+  \else
+    \ifSKV@ask
+      \let\SKV@n@xt\xdef
+    \else
+      \let\SKV@n@xt\edef
+    \fi
+    \SKV@ifundef{#1}{%
+      \SKV@n@xt#1{\@unexp@expox{#2}}%
+    }{%
+      \SKV@n@xt#1{\SKV@expox{#1}\@unexp@expox{#2}}%
+    }%
+  \fi
+}
+\SKV@pdef*\SKV@prepto{\SKV@savstate\SKV@testoptb\SKV@@prepto}
+\SKV@def\SKV@@prepto#1#2{%
+  \ifSKV@st
+    \let\@unexp@expox\SKV@expox
+  \else
+    \let\@unexp@expox\unexpanded
+  \fi
+  \SKV@pr@pto{#1}{#2}%
+  \SKV@resstate
+}
+\SKV@def*\SKV@pr@pto#1#2{%
+  \ifSKV@pl
+    \ifSKV@ask
+      \let\SKV@n@xt\SKV@csxdef
+    \else
+      \let\SKV@n@xt\SKV@csedef
+    \fi
+    \SKV@ifcsundef{#1}{%
+      \SKV@n@xt{#1}{\@unexp@expox{#2}}%
+    }{%
+      \SKV@n@xt{#1}{\@unexp@expox{#2}\SKV@expcsox{#1}}%
+    }%
+  \else
+    \ifSKV@ask
+      \let\SKV@n@xt\xdef
+    \else
+      \let\SKV@n@xt\edef
+    \fi
+    \SKV@ifundef{#1}{%
+      \SKV@n@xt#1{\@unexp@expox{#2}}%
+    }{%
+      \SKV@n@xt#1{\@unexp@expox{#2}\SKV@expox{#1}}%
+    }%
+  \fi
+}
+\SKV@pdef\apptomac#1#2{%
+  \SKV@ifundef{#1}{\edef#1{\unexpanded{#2}}}%
+  {\edef#1{\SKV@expox{#1}\unexpanded{#2}}}%
+}
+\SKV@pdef*\gapptomac{\global\apptomac}
+\SKV@pdef*\csapptomac{\SKV@aftercs\apptomac}
+\SKV@pdef*\csgapptomac{\global\csapptomac}
+\SKV@pdef\preptomac#1#2{%
+  \SKV@ifundef{#1}{\edef#1{\unexpanded{#2}}}%
+  {\edef#1{\unexpanded{#2}\SKV@expox{#1}}}%
+}
+\SKV@pdef*\gpreptomac{\global\preptomac}
+\SKV@pdef*\cspreptomac{\SKV@aftercs\preptomac}
+\SKV@pdef*\csgpreptomac{\global\cspreptomac}
+\SKV@pdef*\SKV@addtolist{\SKV@savstate\SKV@testoptf\SKV@@addtolist}
+\SKV@def*\SKV@@addtolist[#1]{%
+  \def\parser{#1}%
+  \ifSKV@pl
+    \def\SKV@n@xt##1{\SKV@aftercs\SKV@addt@list{##1}}%
+    \ifSKV@ask
+       \let\glob@l@or@def\xdef
+    \else
+      \let\glob@l@or@def\edef
+    \fi
+  \else
+    \let\SKV@n@xt\SKV@addt@list
+    \ifSKV@ask
+      \let\glob@l@or@def\xdef
+    \else
+      \let\glob@l@or@def\edef
+    \fi
+  \fi
+  \SKV@resstate\SKV@n@xt
+}
+\SKV@def\SKV@addt@list#1#2{%
   \SKV@ifundef{#1}{%
-    \xdef#1{\SKV@expandox{#2}}%
+    \glob@l@or@def#1{\SKV@expox{#2}}%
   }{%
-    \xdef#1{\SKV@expandox{#2}\SKV@expandox#1}%
-  }%
+    \glob@l@or@def#1{\SKV@expox{#1}\parser\SKV@expox{#2}}%
+  }%
+}
+\SKV@pdef*\SKV@relax#1{\let#1\relax}
+\SKV@pdef*\SKV@grelax{\global\SKV@relax}
+\SKV@pdef*\SKV@csrelax{\SKV@aftercs\SKV@relax}
+\SKV@pdef*\SKV@csgrelax{\global\SKV@csrelax}
+\@ifpackageloaded{atveryend}{%
+  \@ifpackagecurrent{atveryend}{2010/03/24}{}{%
+    \SKV@err{Your loaded version of atveryend package is
+      not current}\@ehc}}{\RequirePackage{atveryend}[2010/03/24]}
+\SKV@pdef*\SKV@notprerr{%
+  \SKV@err{You have issued a preamble command here}%
+    {Move shown command to document preamble.}%
+}
+\SKV@pdef*\SKV@notenderr{%
+  \SKV@err{You've called an \string\enddocument\space command\SKV@MB
+    at the wrong place}{Move command to before \string\enddocument.}%
+}
+\SKV@pdef*\SKV@AtDocumentStart{\AtBeginDocument}
+\SKV@pdef*\SKV@BeforeDocumentStart{\SKV@appto?\SKV@beforedocstart}
+\def\SKV@beforedocstart{}
+\SKV@prepto\document{%
+  \endgroup
+  \let\SKV@BeforeDocumentStart\@firstofone
+  \SKV@beforedocstart
+  \let\SKV@BeforeDocumentStart\SKV@notprerr
+  \SKV@gundef\SKV@beforedocstart
+  \begingroup
 }
-\SKV@def*\@afterpackageloaded#1{%
-  \SKV@ifnamedef{ver@#1.\@pkgextension}{%
-    \let\SKV@tempa\@firstofone
+\SKV@pdef*\SKV@AfterDocumentStart{\SKV@appto?\SKV@afterdocstart}
+\def\SKV@afterdocstart{}
+\SKV@appto\document{%
+  \let\SKV@AfterDocumentStart\@firstofone
+  \SKV@afterdocstart
+  \let\SKV@AfterDocumentStart\SKV@notprerr
+  \SKV@gundef\SKV@afterdocstart\ignorespaces
+}
+\SKV@BeforeDocumentStart{\let\SKV@AtDocumentStart\@firstofone}
+\SKV@pdef*\SKV@AtDocumentEnd{\AtEndDocument}
+\SKV@pdef*\SKV@BeforeLastPage{\SKV@appto?\SKV@beforelastpage}
+\def\SKV@beforelastpage{}
+\SKV@AtDocumentEnd{%
+  \let\SKV@bef@relastpage\AtVeryEnd@BeforeClearDocumentHook
+  \def\AtVeryEnd@BeforeClearDocumentHook{%
+    \let\SKV@BeforeLastPage\@firstofone
+    \SKV@beforelastpage\SKV@bef@relastpage
+    \let\SKV@BeforeLastPage\SKV@notenderr
+    \SKV@Undef?{\SKV@beforelastpage\SKV@bef@relastpage}%
+  }%
+}
+\SKV@pdef*\SKV@AfterLastPage{\SKV@appto?\SKV@afterlastpage}
+\def\SKV@afterlastpage{}
+\SKV@AtDocumentEnd{%
+  \let\SKV@afterl@stpage\AtVeryEnd@AfterLastShipoutHook
+  \def\AtVeryEnd@AfterLastShipoutHook{%
+    \let\SKV@AfterLastPage\@firstofone
+    \SKV@afterlastpage\SKV@afterl@stpage
+    \let\SKV@AfterLastPage\SKV@notenderr
+    \SKV@Undef?{\SKV@afterlastpage\SKV@afterl@stpage}%
+  }%
+}
+\SKV@pdef*\SKV@AfterDocumentEnd{\SKV@appto?\SKV@afterenddoc}
+\def\SKV@afterenddoc{}
+\SKV@AtDocumentEnd{%
+  \let\SKV@aft@renddoc\AtVeryEnd@AtVeryEndDocumentHook
+  \def\AtVeryEnd@AtVeryEndDocumentHook{%
+    \let\SKV@AfterDocumentEnd\@firstofone
+    \SKV@afterenddoc\SKV@aft@renddoc
+    \let\SKV@AfterDocumentEnd\SKV@notenderr
+    \SKV@Undef?{\SKV@afterenddoc\SKV@aft@renddoc}%
+  }%
+}
+\SKV@pdef\SKV@AtPackageEnd{\AtEndOfPackage}
+\SKV@pdef*\SKV@BeforePackageEnd{%
+  \SKV@prepto+{\@currname.\@currext-h@@k}%
+}
+\SKV@pdef*\SKV@AfterPackageEnd{%
+  \SKV@appto+{\@currname.\@currext-skvh@@k}%
+}
+\let\SKV@AtClassEnd\SKV@AtPackageEnd
+\let\SKV@BeforeClassEnd\SKV@BeforePackageEnd
+\let\SKV@AfterClassEnd\SKV@AfterPackageEnd
+\SKV@prepto\@popfilename{%
+  \SKV@csuse{\@currname.\@currext-skvh@@k}%
+  \SKV@csgundef{\@currname.\@currext-skvh@@k}%
+}
+\SKV@pdef\@afterpackageloaded#1{%
+  \SKV@AtDocumentStart{%
+    \SKV@ifcsdef{ver@#1.\@pkgextension}{}{%
+      \SKV@warn{Package '#1' was never loaded}%
+    }%
+  }
+  \SKV@ifcsdef{ver@#1.\@pkgextension}{%
+    \let\SKV@n@xt\@firstofone
   }{%
-    \def\SKV@tempa{\SKV@aftercsname\SKV@apptomacro@a{#1.\@pkgextension @afpl}}%
+    \def\SKV@n@xt{\SKV@appto+{#1.\@pkgextension-skvh@@k}}%
   }%
-  \SKV@tempa
+  \SKV@n@xt
 }
-\SKV@preptomacro@a\@popfilename{%
-  \SKV@nameuse{\@currname.\@currext @afpl}%
-  \SKV@nameundef{\@currname.\@currext @afpl}%
+\let\SKV@steno\z@
+\SKV@pdef*\SKV@for{\SKV@savstate\SKV@testoptd\SKV@@for}
+\SKV@pdef*\SKV@@for[#1]{%
+  \let\SKV@steno\@ne
+  \ifSKV@st
+    \def\SKV@n@xt{\SKV@for@b[#1]}%
+  \else
+    \def\SKV@n@xt{\SKV@CommandGenParser{#1}\SKV@for@a}%
+  \fi
+  \SKV@n@xt
 }
-\@onlypreamble\@afterpackageloaded
-\SKV@def\ReserveKeyPrefixNames#1{\SKV@apptomacro@a\SKV@rkpnames{,#1}}
-\SKV@def\ReserveMacroPrefixNames#1{\SKV@apptomacro@a\SKV@rmpnames{,#1}}
-\SKV@def\ReserveFamilyNames#1{\SKV@apptomacro@a\SKV@rfnames{,#1}}
-\SKV@def*\SKV@rkpnames{XKV}
-\SKV@def*\SKV@rmpnames{XKV}
-\SKV@def*\SKV@rfnames{XKV}
 \SKV@pdef*\SKV@CommandGenParser#1{%
   \def\parser{#1}%
   \protected\long\def\SKV@for@a##1##2##3{%
-    \edef##2{\unexpanded{##1}}%
-    \SKV@oifblank{##2}\SKV@fornoop\SKV@forloop
-    ##2{##3}##1#1\SKV@nil#1%
+    \SKV@ifblank{##1}\SKV@fornoop\SKV@forloop
+    ##2{##3}##1#1\@nil
   }%
-  \long\def\SKV@forloop##1##2##3#1{%
+  \long\def\SKV@forloop##1##2##3#1##4\@nil{%
     \edef##1{\unexpanded{##3}}%
-    \ifx##1\SKV@nnil
-      \expandafter\@gobbletwo
-    \else
-      ##2\expandafter\SKV@forloop
-    \fi
-    ##1{##2}%
+    \SKV@ifstrequal{##3}{\listbreak}{%
+      \SKV@keylistrema##4\@nil#1%
+    }{%
+      \SKV@ifblank{##4}{%
+        ##2\relax
+        \ifnum\SKV@steno=\@ne\expandafter\SKV@resstate\fi
+        \let\SKV@steno\z@
+      }{%
+        ##2\relax\SKV@forloop##1{##2}##4\@nil
+      }%
+    }%
   }%
-  \long\def\SKV@fornoop##1\SKV@nil#1{}%
+  \long\def\SKV@fornoop##1\@nil{}%
 }
-\SKV@pdef\SKV@for@b#1{\expandafter\SKV@for@a\expandafter{#1}}
-\SKV@pdef*\SKV@tfor@a#1#2#3{\SKV@ifblank{#2}{}{\@tf@r#1{#2}\do{#3}}}
-\SKV@pdef*\SKV@tfor@b#1#2#3{%
-  \SKV@expandargs{3}{\SKV@tfor@a#1}{{\SKV@expandox{#2}}}{{#3}}\SKV@nil
+\SKV@pdef*\SKV@for@b{\SKV@testopt\SKV@@for@b{,}}
+\SKV@def\SKV@@for@b[#1]#2{%
+  \SKV@CommandGenParser{#1}%
+  \SKV@expnext\SKV@for@a{#2}%
 }
-\SKV@def\SKV@checksanitizec#1#2{%
-  \XKV@ch@cksanitize{#1}#2;%
-  \ifin@\else\XKV@ch@cksanitize{#1}#2,\fi
-  \ifin@\@selective@sanitize[0]{,;}#2\fi
+\SKV@pdef*\SKV@tfor{\SKV@ifstar\SKV@tfor@b\SKV@tfor@a}
+\SKV@pdef*\SKV@tfor@a#1#2#3{%
+  \SKV@ifblank{#1}{%
+    \SKV@vbsmsg{warn}{Empty list for '\string\SKV@tfor@a'\on@line}%
+  }{%
+    \SKV@ifblank{#3}{%
+      \SKV@vbsmsg{warn}%
+        {Empty function for '\string\SKV@tfor@a'\on@line}%
+    }{%
+      \SKV@tforloop#1\@nil\@nil&#2{#3}%
+    }%
+  }%
+}
+\SKV@def\SKV@tforloop#1#2&#3#4{%
+  \long\def#3{#1}%
+  \SKV@ifstrequal{#1}{\listbreak}{%
+    \let\SKV@n@xt\SKV@tforrema
+  }{%
+    \SKV@ifstrequal{#1}{\@nil}{%
+      \let\SKV@n@xt\SKV@tfornoop
+    }{%
+      #4\relax\let\SKV@n@xt\SKV@tforloop
+    }%
+  }%
+  \SKV@n@xt#2&#3{#4}%
+}
+\SKV@def\SKV@tfornoop#1&#2#3{}
+\SKV@pdef*\SKV@tforrema#1\@nil\@nil&#2#3{%
+  \long\edef\SKV@remainder{\unexpanded{#1}}%
+}
+\SKV@pdef*\SKV@tfor@b#1#2#3{\SKV@expnext\SKV@tfor@a{#1}#2{#3}}
+\SKV@def*\SKV@preamblecmds{}
+\SKV@pdef*\SKV@onlypreamble#1{%
+  \SKV@tfor{#1}\SKV@resvd{%
+    \SKV@expnext\SKV@ensurescape\SKV@resvd
+    \expandafter\gapptomac\expandafter\SKV@preamblecmds
+      \expandafter{\expandafter\SKV@do@a\SKV@resvd}%
+  }%
+}
+\SKV@AfterDocumentStart{%
+  \gdef\SKV@do@a#1{%
+    \gdef#1{\SKV@err{'\string#1' is a preamble command}%
+      {Move command '\string#1' to document preamble.}}%
+  }%
+  \SKV@preamblecmds
+  \global\let\SKV@do@a\@gobble
+}
+\SKV@pdef*\SKV@onlypackage{%
+  \SKV@xifempty{\@currname\@currext}{%
+    \SKV@err{Not in package environment}%
+    {The command at top level of this message\SKV@MB
+      is available only in package environment.}%
+  }{}%
 }
 \SKV@def*\SKV@CommandKeyParser#1{%
   \long\def\SKV@define@keylist##1{%
-    \ifXKV@st
-      \long\expandafter\def\expandafter\SKV@tempa\expandafter{##1}%
-    \else
-      \long\def\SKV@tempa{##1}%
-    \fi
-    \SKV@expandargs{3}\SKV@checksanitizec{{\SKV@expandox{\SKV@tempa}}}%
-      \SKV@tempa\SKV@nil
-    \def\SKV@nob{\z@}%
-    \expandafter\SKV@readkeylist\SKV@tempa#1\SKV@nil
+    \SKV@undeflt{g}{\skif,\skifx,\skifcase,\skor,\skelse,\skfi}%
+    \ifswitchon{SKV@st}{%
+      \long\edef\@keylist{\SKV@expox{##1}}%
+    }{%
+      \long\def\@keylist{##1}%
+    }%
+    \SKV@resstate
+    \SKV@expnext\SKV@checksanitizec\@keylist\SKV@tempa
+    \expandafter\SKV@readkeylist\SKV@tempa#1\@nil
   }%
-  \long\def\SKV@readkeylist##1#1##2\SKV@nil{%
-    \SKV@ifblank{##1}\relax
+  \long\def\SKV@readkeylist##1#1##2\@nil{%
+    \SKV@ifblank{##1}{}%
     {%
-      \SKV@ifstrequal{##1}{\stopread}{%
-        \def\SKV@nob{\@ne}%
-        \stopread##2\SKV@nil
+      \SKV@ifstrequal{##1}{\listbreak}{%
+        \SKV@keylistrema##2\@nil#1%
       }{%
-        \SKV@define@mult@keys##1\SKV@nil
+        \SKV@define@multkeys##1\@nil
+        \SKV@ifblank{##2}\relax{\SKV@readkeylist##2\@nil}%
       }%
     }%
-    \ifnum\SKV@nob=\z@
-      \SKV@ifblank{##2}\relax{\SKV@readkeylist##2\SKV@nil}%
-    \fi
   }%
 }
-\SKV@def\SKV@expandargs#1#2#3#4\SKV@nil{%
-  \begingroup
-  \protected@edef\SKV@tempa{\endgroup
-    \ifcase#1\relax
-      \unexpanded{#2}{#3}%
-    \or
-      \unexpanded{#2#3}{#4}%
-    \or
-      \unexpanded{#2}{#3}{#4}%
-    \or
-      \unexpanded{#2}#3\unexpanded{#4}%
-    \else
-      \SKV@err{Unknown expansion type '#1' for \string\SKV@expandargs}%
-        {Use the right expansion identifier (0 - 3)}%
-    \fi
-  }%
-  \SKV@tempa
+\SKV@def\SKV@checksanitizec#1#2{%
+  \XKV@ch@cksanitize{#1}#2;%
+  \ifin@\else\XKV@ch@cksanitize{#1}#2,\fi
+  \ifin@\@selective@sanitize[0]{,;}#2\fi
 }
 \SKV@pdef\SKV@checkchoice#1#2#3#4{%
-  \SKV@expandargs{3}{\XKV@cc*+[\val\nr]}{{#1}{#2}}{{#3}{#4}}\SKV@nil
+  \XKV@sttrue\XKV@pltrue
+  \SKV@expargs{3}{\XKV@checkchoice[\val\nr]}{{#1}{#2}}{{#3}{#4}}\@nil
 }
 \SKV@pdef*\SKV@inputerr#1#2{%
   \SKV@err{Erroneous value '#1' for key '#2'}{%
     Please use the correct value for key '#2'.}%
 }
-\SKV@def\SKV@ifblank#1{\SKV@ifbl@nk#1\SKV@nil\SKV@nil\@secondoftwo\@firstoftwo:}
-\SKV@def\SKV@ifbl@nk#1#2\SKV@nil#3#4#5:{#4}
-\SKV@def\SKV@oifblank#1{\SKV@expandargs{0}\SKV@ifblank{\SKV@expandox{#1}}\SKV@nil}
-\SKV@def\SKV@xifblank#1{\SKV@expandargs{0}\SKV@ifblank{#1}\SKV@nil}
-\SKV@def\SKV@ifstrequal#1#2{%
+\SKV@def*\SKV@despacelist{\SKV@savstate\SKV@testoptd\SKV@despac@list}
+\SKV@def*\SKV@despac@list[#1]#2{%
   \begingroup
-  \edef\SKV@tempa{\detokenize{#1}}%
-  \edef\SKV@tempb{\detokenize{#2}}%
-  \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@expandargs{1}\KV@@sp@def\SKV@tempb\SKV@tempb\SKV@nil
-  \ifx\SKV@tempa\SKV@tempb
-    \aftergroup\@firstoftwo
+  \let\SKV@resa\@empty
+  \ifSKV@st
+    \def\SKV@dsl{\SKV@for*[#1]#2}%
   \else
-    \aftergroup\@secondoftwo
+    \def\SKV@dsl{\SKV@for[#1]{#2}}%
   \fi
+  \SKV@dsl\SKV@dsl{%
+    \SKV@despace\SKV@dsl
+    \SKV@appto*\SKV@resa{\expandafter#1\SKV@dsl}%
+  }%
+  \ifx\SKV@resa\@empty\else\SKV@remparser[#1]\SKV@resa\fi
+  \ifSKV@st\global\let#2\SKV@resa\fi
   \endgroup
+  \SKV@resstate
+}
+\SKV@def*\SKV@tdespacelt#1{%
+  \SKV@tfor{#1}\SKV@dsl{\expandafter\SKV@despace\SKV@dsl}%
+}
+\SKV@pdef*\ReserveKeyPrefixNames{\SKV@ifstar\SKV@rkpn@mes\SKV@rkpn@m@s}
+\SKV@def*\SKV@rkpn@mes#1{\SKV@AfterPackageEnd{\gapptomac\SKV@rkpnames{,#1}}}
+\SKV@def*\SKV@rkpn@m@s#1{\gapptomac\SKV@rkpnames{,#1}}
+\SKV@pdef*\ReserveMacroPrefixNames{\SKV@ifstar\SKV@rmpn@mes\SKV@rmpn@m@s}
+\SKV@def*\SKV@rmpn@mes#1{\SKV@AfterPackageEnd{\gapptomac\SKV@rmpnames{,#1}}}
+\SKV@def*\SKV@rmpn@m@s#1{\gapptomac\SKV@rmpnames{,#1}}
+\SKV@pdef*\ReserveFamilyNames{\SKV@ifstar\SKV@rfn@mes\SKV@rfn@m@s}
+\SKV@def*\SKV@rfn@mes#1{\SKV@AfterPackageEnd{\gapptomac\SKV@rfnames{,#1}}}
+\SKV@def*\SKV@rfn@m@s#1{\gapptomac\SKV@rfnames{,#1}}
+\SKV@def*\SKV@rkpnames{XKV}
+\SKV@def*\SKV@rmpnames{XKV}
+\SKV@def*\SKV@rfnames{XKV}
+\ReserveKeyPrefixNames*{SKV}
+\ReserveMacroPrefixNames*{SKV}
+\ReserveFamilyNames*{skeyval}
+\SKV@def*\SKV@newlet#1#2{%
+  \SKV@ifdef#1{%
+    \SKV@err{Command '\string#1' already defined}%
+    {I can't let '\string#1' to '\string#2'.}%
+  }{%
+    \SKV@ifdef#2{\let#1#2}{%
+      \SKV@err{Command '\string#2' undefined}%
+        {I can't let '\string#1' to '\string#2'.}%
+    }%
+  }%
 }
-\SKV@def\SKV@oifstrequal#1#2{%
-  \@expandtwoargs\SKV@ifstrequal{\SKV@expandox{#1}}{\SKV@expandox{#2}}%
+\AtEndOfPackage{\SKV@providedef*\NewLet{\SKV@newlet}}
+\SKV@pdef*\SKV@cslet{\SKV@savstate\SKV@t@stopta\SKV@@cslet}
+\SKV@def*\SKV@@cslet#1#2{%
+  \ifSKV@st
+    \def\SKV@n@xt{\SKV@aftercs\let{#1}#2}%
+  \else
+    \def\SKV@n@xt{%
+      \SKV@ifdef{#2}{%
+        \SKV@aftercs\let{#1}#2%
+      }{%
+        \SKV@err{Command '\string#2' undefined}%
+          {You may use the starred version of \string\SKV@cslet.}%
+      }%
+    }%
+  \fi
+  \SKV@resstate\SKV@n@xt
+}
+\SKV@pdef*\SKV@letcs{\SKV@savstate\SKV@t@stopta\SKV@@letcs}
+\SKV@def*\SKV@@letcs#1#2{%
+  \ifSKV@st
+    \def\SKV@n@xt{%
+      \begingroup\expandafter\endgroup
+      \expandafter\let\expandafter#1\csname#2\endcsname
+    }%
+  \else
+    \def\SKV@n@xt{%
+      \SKV@ifcsdef{#2}{%
+        \expandafter\let\expandafter#1\csname#2\endcsname
+      }{%
+        \SKV@err{Command '\@backslashchar#2' undefined}%
+          {You may use the starred version of \string\SKV@letcs.}%
+      }%
+    }%
+  \fi
+  \SKV@resstate\SKV@n@xt
+}
+\SKV@pdef*\SKV@csletcs{\SKV@savstate\SKV@t@stopta\SKV@@csletcs}
+\SKV@def*\SKV@@csletcs#1#2{%
+  \ifSKV@st
+    \def\SKV@n@xt{%
+      \begingroup\expandafter\endgroup
+      \expandafter\let\csname#1\SKV@aftercs\endcsname{#2}%
+    }%
+  \else
+    \def\SKV@n@xt{%
+      \SKV@ifcsdef{#2}{%
+        \SKV@aftercs\let{#1\SKV@aftercs}{#2}%
+      }{%
+        \SKV@err{Command '\@backslashchar#2' undefined}%
+          {You may use the starred version of \string\SKV@csletcs.}%
+      }%
+    }%
+  \fi
+  \SKV@resstate\SKV@n@xt
+}
+\SKV@pdef*\SKV@numdef{\SKV@savstate\SKV@testoptc\SKV@@numdef}
+\SKV@pdef*\SKV@@numdef{%
+  \ifSKV@pl
+    \def\SKV@n@xt##1{\SKV@aftercs\SKV@numd@f{##1}}%
+    \ifSKV@ask
+       \let\glob@lrel@x\global
+    \else
+      \let\glob@lrel@x\relax
+    \fi
+  \else
+    \let\SKV@n@xt\SKV@numd@f
+    \ifSKV@ask
+      \let\glob@lrel@x\global
+    \else
+      \let\glob@lrel@x\relax
+    \fi
+  \fi
+  \SKV@resstate\SKV@n@xt
 }
-\SKV@def\SKV@xifstrequal#1#2{\@expandtwoargs\SKV@ifstrequal{#1}{#2}}
-\SKV@def\SKV@ifstrempty#1{%
-  \romannumeral-`\@\csname @\if @\detokenize{#1}@first\else
-  second\fi oftwo\endcsname
+\SKV@pdef*\SKV@numd@f#1#2{%
+  \SKV@ensurescape@notempty{#1}{#2}%
+  \SKV@ifundef{#1}{%
+    \newcount#1\glob@lrel@x#1=\numexpr#2\relax
+  }{%
+    \glob@lrel@x#1=\numexpr#2\relax
+  }%
+}
+\SKV@pdef*\SKV@dimdef{\SKV@savstate\SKV@testoptc\SKV@@dimdef}
+\SKV@pdef*\SKV@@dimdef{%
+  \ifSKV@pl
+    \def\SKV@n@xt##1{\SKV@aftercs\SKV@dimd@f{##1}}%
+    \ifSKV@ask
+       \let\glob@lrel@x\global
+    \else
+      \let\glob@lrel@x\relax
+    \fi
+  \else
+    \let\SKV@n@xt\SKV@dimd@f
+    \ifSKV@ask
+      \let\glob@lrel@x\global
+    \else
+      \let\glob@lrel@x\relax
+    \fi
+  \fi
+  \SKV@resstate\SKV@n@xt
+}
+\SKV@pdef*\SKV@dimd@f#1#2{%
+  \SKV@ensurescape@notempty{#1}{#2}%
+  \SKV@ifundef{#1}{%
+    \newdimen#1\glob@lrel@x#1=\dimexpr#2\relax
+  }{%
+    \glob@lrel@x#1=\dimexpr#2\relax
+  }%
+}
+\SKV@def*\SKV@ensurescape@notempty#1#2{%
+  \SKV@ensurescape{#1}%
+  \SKV@ifempty{#2}{\SKV@err{Argument '\string#1' is empty}\@ehc}{}%
 }
-\SKV@def\SKV@oifstrempty#1{%
-  \SKV@expandargs{0}\SKV@ifstrempty{\SKV@expandox{#1}}\SKV@nil}
-\SKV@def\SKV@xifstrempty#1{\SKV@expandargs{0}\SKV@ifstrempty{#1}\SKV@nil}
 \SKV@def*\SKV@keylistparser@err{%
   \SKV@err{Key list parser '\SKV@keyparser' not allowed}%
     {Use semicolon (preferable) or colon as parser.}%
@@ -408,37 +1276,33 @@
 \define@boolkey+[KV]{skeyval}[SKV@]{xchoicelist}[true]{}{%
   \SKV@inputerr{#1}{xchoicelist}%
 }
-\define@boolkey+[KV]{skeyval}[SKV@]{inputonce}[true]{}{%
-  \SKV@inputerr{#1}{inputonce}%
-}
 \define@cmdkey[KV]{skeyval}[SKV@]{genparser}[,]{%
   \@onelevel@sanitize\SKV@genparser
-  \SKV@expandargs{1}\KV@@sp@def\SKV@genparser\SKV@genparser\SKV@nil
-  \SKV@expandargs{0}\SKV@CommandGenParser\SKV@genparser\SKV@nil
+  \SKV@despace\SKV@genparser
+  \SKV@expargs{0}\SKV@CommandGenParser\SKV@genparser\@nil
 }
 \define@cmdkey[KV]{skeyval}[SKV@]{keyparser}[;]{%
   \@onelevel@sanitize\SKV@keyparser
   \SKV@xifblank\SKV@keyparser\SKV@keylistparser@err\relax
-  \SKV@expandargs{1}\KV@@sp@def\SKV@keyparser\SKV@keyparser\SKV@nil
+  \SKV@despace\SKV@keyparser
   \begingroup
-  \edef\SKV@tempa{\detokenize{,}}%
-  \ifx\SKV@keyparser\SKV@tempa
-    \aftergroup\SKV@keylistparser@err
-  \fi
+  \SKV@detokdespace{,}\SKV@tempa
+  \SKV@ifx\SKV@keyparser\SKV@tempa
+    {\aftergroup\SKV@keylistparser@err}{}%
   \endgroup
-  \SKV@expandargs{0}\SKV@CommandKeyParser\SKV@keyparser\SKV@nil
+  \SKV@expargs{0}\SKV@CommandKeyParser\SKV@keyparser\@nil
 }
 \SKV@def*\SKV@keyprefix@err{%
   \SKV@err{Key prefix '\SKV@keyprefix' is not allowed}%
-    {Use another prefix instead of '\SKV@keyprefix'.}%
+    {Use another prefix name instead of '\SKV@keyprefix'.}%
 }
 \define@cmdkey[KV]{skeyval}[SKV@]{keyprefix}[KV]{%
   \SKV@xifblank\SKV@keyprefix\SKV@keyprefix@err\relax
-  \SKV@expandargs{1}\KV@@sp@def\SKV@keyprefix\SKV@keyprefix\SKV@nil
-  \SKV@expandargs{3}\XKV@checksanitizeb{{\SKV@rkpnames}}\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \ifx\SKV@keyprefix\SKV@tempa\SKV@afterfi\SKV@keyprefix@err\fi
+  \SKV@despace\SKV@keyprefix
+  \SKV@expargs{3}\XKV@checksanitizeb{{\SKV@rkpnames}}%
+    \SKV@tempa\@nil
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@ifx\SKV@keyprefix\SKV@tempa\SKV@keyprefix@err\relax
   }%
 }
 \SKV@def*\SKV@keyfamily@err{%
@@ -447,324 +1311,258 @@
 }
 \define@cmdkey[KV]{skeyval}[SKV@]{keyfamily}[fam]{%
   \SKV@xifblank\SKV@keyfamily\SKV@keyfamily@err\relax
-  \SKV@expandargs{1}\KV@@sp@def\SKV@keyfamily\SKV@keyfamily\SKV@nil
-  \SKV@expandargs{3}\XKV@checksanitizeb{{\SKV@rfnames}}\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \ifx\SKV@keyfamily\SKV@tempa\SKV@afterfi\SKV@keyfamily@err\fi
+  \SKV@despace\SKV@keyfamily
+  \SKV@expargs{3}\XKV@checksanitizeb{{\SKV@rfnames}}%
+    \SKV@tempa\@nil
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@ifx\SKV@keyfamily\SKV@tempa\SKV@keyfamily@err\relax
   }%
 }
 \SKV@def*\SKV@macroprefix@err{%
   \SKV@err{Macro prefix '\SKV@macroprefix' is not allowed}%
-    {Use another macro prefix.}%
+    {Use another macro prefix name instead of '\SKV@macroprefix'.}%
 }
 \define@cmdkey[KV]{skeyval}[SKV@]{macroprefix}[mp@]{%
   \SKV@xifblank\SKV@macroprefix\SKV@macroprefix@err\relax
-  \SKV@expandargs{1}\KV@@sp@def\SKV@macroprefix\SKV@macroprefix\SKV@nil
-  \SKV@expandargs{3}\XKV@checksanitizeb{{\SKV@rmpnames}}\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \ifx\SKV@macroprefix\SKV@tempa\SKV@afterfi\SKV@macroprefix@err\fi
-  }%
+  \SKV@despace\SKV@macroprefix
+  \SKV@expargs{3}\XKV@checksanitizeb{{\SKV@rmpnames}}%
+    \SKV@tempa\@nil
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@ifx\SKV@macroprefix\SKV@tempa\SKV@macroprefix@err\relax
+  }%
+}
+\SKV@BeforePackageEnd{\deftog{draft}\deftog{final}}
+\define@boolkey+[KV]{skeyval}[SKV@]{draft}[true]{%
+  \ifSKV@draft
+    \setkeys[KV]{skeyval}{final=false}%
+    \SKV@AtPackageEnd{\ifSKV@draft\togtrue{draft}\else
+      \togfalse{draft}\fi}%
+  \fi
+}{%
+  \SKV@inputerr{#1}{draft}%
+}
+\define@boolkey+[KV]{skeyval}[SKV@]{final}[true]{%
+  \ifSKV@final
+    \setkeys[KV]{skeyval}{draft=false}%
+    \SKV@AtPackageEnd{\ifSKV@final\togtrue{final}\else
+      \togfalse{final}\fi}%
+  \fi
+}{%
+  \SKV@inputerr{#1}{final}%
 }
 \DeclareOptionX*{\SKV@warn{Unknown option '\CurrentOption' ignored}}
 \ExecuteOptionsX[KV]<skeyval>{genparser,keyparser,keyprefix,
-  keyfamily,macroprefix,inputonce}
+  keyfamily,macroprefix,final}
 \ProcessOptionsX*[KV]<skeyval>\relax
 \SKV@pdef*\skvoptions#1{\setkeys[KV]{skeyval}{#1}}
-\SKV@def*\SKV@despacelist#1#2{%
-  \SKV@CommandGenParser{#1}%
-  \let\SKV@tempa#2%
-  \let#2\@empty
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-    \SKV@apptomacro@b#2{\expandafter#1\SKV@tempa}%
-  }%
-  \ifx#2\@empty\else
-    \SKV@remparser{#1}#2%
-  \fi
-}
-\SKV@def\SKV@named@f#1#2{%
-  \ifcsname#2\endcsname
-    \expandafter\ifx\csname#2\endcsname\relax\else
-      \def\reserved@a{#2}%
-      \expandafter\expandafter\expandafter\@notdefinable
-    \fi
-  \else
-    \expandafter#1\csname#2\expandafter\endcsname
-  \fi
-}
-\SKV@def*\SKV@newnamedef#1{\SKV@named@f\def{#1}}
-\SKV@def*\SKV@newnamegdef#1{\SKV@named@f\gdef{#1}}
-\SKV@def*\SKV@newnameedef#1{\SKV@named@f\edef{#1}}
-\SKV@def*\SKV@newnamexdef#1{\SKV@named@f\xdef{#1}}
-\SKV@def*\SKV@namedef#1{\SKV@aftercsname\def{#1}}
-\SKV@def*\SKV@namegdef#1{\SKV@aftercsname\gdef{#1}}
-\SKV@def*\SKV@nameedef#1{\SKV@aftercsname\edef{#1}}
-\SKV@def*\SKV@namexdef#1{\SKV@aftercsname\xdef{#1}}
-\SKV@def*\SKV@nameuse#1{%
-  \ifcsname#1\endcsname\csname#1\expandafter\endcsname\fi}
-\SKV@def\SKV@ifnextchar#1#2#3{%
-  \let\SKV@@tempc=#1\def\SKV@@tempa{#2}\def\SKV@@tempb{#3}%
-  \futurelet\@temptoks\SKV@ifnextch@r
-}
-\SKV@def\SKV@ifnextch@r{%
-  \ifx\@temptoks\SKV@@tempc\let\SKV@@tempb\SKV@@tempa\fi
-  \SKV@@tempb
+\SKV@pdef*\SKV@ifdraft{\@nameuse{@\ifSKV@draft first\else second\fi oftwo}}
+\SKV@pdef*\SKV@iffinal{\@nameuse{@\ifSKV@final first\else second\fi oftwo}}
+\SKV@pdef*\SKV@ifnotdraft{\SKV@ifdraft\@secondoftwo\@firstoftwo}
+\SKV@pdef*\SKV@ifnotfinal{\SKV@iffinal\@secondoftwo\@firstoftwo}
+\def\SKV@useinfo#1{Not using '\@backslashchar#1' of 'skyeval' package}
+\AtBeginDocument{%
+  \SKV@ifundef\ifdraft
+    {\SKV@pdef*\ifdraft{\SKV@ifdraft}}%
+    {\SKV@vbsmsg{info}{\SKV@useinfo{ifdraft}}}%
+}
+\SKV@ifundef\ifnotdraft
+  {\SKV@pdef*\ifnotdraft{\SKV@ifnotdraft}}%
+  {\SKV@vbsmsg{info}{\SKV@useinfo{ifnotdraft}}}
+\SKV@ifundef\iffinal
+  {\SKV@pdef*\iffinal{\SKV@iffinal}}%
+  {\SKV@vbsmsg{info}{\SKV@useinfo{iffinal}}}
+\SKV@ifundef\ifnotfinal
+  {\SKV@pdef*\ifnotfinal{\SKV@ifnotfinal}}%
+  {\SKV@vbsmsg{info}{\SKV@useinfo{ifnotfinal}}}
+\SKV@def\SKV@star@or@long#1{%
+  \SKV@ifstar
+    {\let\l@ngrel@x\relax\def\@star@or@none{*}#1}%
+    {\let\l@ngrel@x\long\def\@star@or@none{}#1}%
 }
-\SKV@def\SKV@testopt#1#2{\SKV@ifnextchar[{#1}{#1[{#2}]}}
-\SKV@def\SKV@ifstar#1#2{%
-  \SKV@ifnextchar*{\begingroup
-    \def\SKV@tempa*{\endgroup #1}\SKV@tempa}{#2}%
+\SKV@pdef\requirecmd{\SKV@star@or@long\SKV@require@cmd}
+\SKV@def\SKV@require@cmd#1{%
+  \SKV@ensurescape{#1}%
+  \SKV@ifdefined{#1}%
+    {\CheckCommand\@star@or@none}{\newcommand\@star@or@none}{#1}%
 }
-\SKV@def*\SKV@newlet#1#2{%
-  \SKV@ifdef#1{%
-    \SKV@err{Command '\string#1' already defined}{%
-      I can't let '\string#1' to '\string#2'.}%
-  }{%
-    \SKV@ifdef#2{%
-      \let#1#2%
-    }{%
-      \SKV@err{Command '\string#2' undefined}{%
-        I can't let '\string#1' to '\string#2'.}%
+\def\@check@eq#1#2{%
+  \SKV@ifx{#1}{#2}{}{%
+    \SKV@vbsmsg{warn}{%
+      Previous definition of '\string#1'\SKV@MB
+      doesn't match your new definition.\SKV@MB
+      * I haven't redefined '\string#1' *}%
+  }%
+}
+\SKV@pdef*\newswitch#1#2{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifstrequal{#2}{true}{\def\SKV@resvd{true}}{%
+    \SKV@ifstrequal{#2}{false}{\def\SKV@resvd{false}}{%
+      \SKV@ifstrequal{#2}{on}{\def\SKV@resvd{true}}{%
+        \SKV@ifstrequal{#2}{off}{\def\SKV@resvd{false}}{%
+          \SKV@swvalerr{#1}{#2}%
+        }%
+      }%
     }%
   }%
-}
-\SKV@pdef*\SKV@newtoks#1{\SKV@ifdefinable#1{\@nameuse{newtoks}#1}}
-\SKV@pdef*\SKV@newcount#1{\SKV@ifdefinable#1{\@nameuse{newcount}#1}}
-\SKV@pdef*\SKV@newdimen#1{\SKV@ifdefinable#1{\@nameuse{newdimen}#1}}
-\SKV@def*\nameletcs#1#2{%
-  \SKV@ifdef{#2}{%
-    \SKV@aftercsname\let{#1}#2%
-  }{%
-    \SKV@err{Command '\string#2' undefined}\@ehc
-  }%
-}
-\SKV@def*\csletname#1#2{%
-  \SKV@ifnamedef{#2}{%
-    \expandafter\let\expandafter#1\csname#2\endcsname
-  }{%
-    \SKV@err{Command '\@backslashchar#2' undefined}\@ehc
-  }%
-}
-\SKV@def*\nameletname#1#2{%
-  \SKV@ifnamedef{#2}{%
-    %\expandafter\let\csname#1\expandafter\endcsname\csname#2\endcsname
-    \SKV@aftercsname\let{#1\SKV@aftercsname}{#2}%
-  }{%
-    \SKV@err{Command '\@backslashchar#2' undefined}\@ehc
-  }%
-}
-\SKV@def*\@nameletcs#1#2{\SKV@aftercsname\let{#1}#2}
-\SKV@def*\@csletname#1#2{%
-  \begingroup\expandafter\endgroup
-  \expandafter\let\expandafter#1\csname#2\endcsname
-}
-\SKV@def*\@nameletname#1#2{%
-  \begingroup\expandafter\endgroup
-  \expandafter\let\csname#1\SKV@aftercsname\endcsname{#2}%
-}
-\SKV@pdef*\SKV@numdef#1#2{%
-  \SKV@findescape{#1}{}{\SKV@err{Backslash required in '#1'}\@ehc}%
-  \SKV@ifstrempty{#2}{\SKV@err{Empty argument for counter '#1'}\@ehc}{}%
-  \SKV@ifundef{#1}{%
-    \newcount#1#1=\numexpr#2\relax
-  }{%
-    #1=\numexpr#2\relax
+  \expandafter\SKV@ifdefinable\csname if#1\endcsname{%
+    \csname newif\expandafter\endcsname\csname if#1\endcsname
+    \csname #1\SKV@resvd\endcsname
   }%
 }
-\SKV@pdef*\SKV@numnamedef#1{\SKV@aftercsname\SKV@numdef{#1}}
-\SKV@pdef*\SKV@numgdef#1#2{%
-  \SKV@findescape{#1}{}{\SKV@err{Backslash required in '#1'}\@ehc}%
-  \SKV@ifstrempty{#2}{\SKV@err{Empty argument for counter '#1'}\@ehc}{}%
-  \SKV@ifundef{#1}{%
-    \newcount#1\global#1=\numexpr#2\relax
+\SKV@newlet\NewSwitches\NewIfs
+\SKV@def*\setswitch#1#2{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsundef{if#1}{%
+    \SKV@noswerr{#1}%
   }{%
-    \global#1=\numexpr#2\relax
+    \SKV@ifstrequal{#2}{true}{\def\SKV@resvd{true}}{%
+      \SKV@ifstrequal{#2}{false}{\def\SKV@resvd{false}}{%
+        \SKV@ifstrequal{#2}{on}{\def\SKV@resvd{true}}{%
+          \SKV@ifstrequal{#2}{off}{\def\SKV@resvd{false}}{%
+            \SKV@swvalerr{#1}{#2}%
+          }%
+        }%
+      }%
+    }%
+    \csname#1\SKV@resvd\endcsname
   }%
 }
-\SKV@pdef*\SKV@numnamegdef#1{\SKV@aftercsname\SKV@numgdef{#1}}
-\SKV@pdef*\SKV@dimdef#1#2{%
-  \SKV@findescape{#1}{}{\SKV@err{Backslash required in '#1'}\@ehc}%
-  \SKV@ifstrempty{#2}{\SKV@err{Empty argument for dimension '#1'}\@ehc}{}%
-  \SKV@ifundef{#1}{%
-    \newdimen#1#1=\dimexpr#2\relax
-  }{%
-    #1=\dimexpr#2\relax
-  }%
+\SKV@def*\switchon#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsundef{if#1}{\SKV@noswerr{#1}}{\@nameuse{#1true}}%
 }
-\SKV@pdef*\SKV@dimnamedef#1{\SKV@aftercsname\SKV@dimdef{#1}}
-\SKV@pdef*\SKV@dimgdef#1#2{%
-  \SKV@findescape{#1}{}{\SKV@err{Backslash required in '#1'}\@ehc}%
-  \SKV@ifstrempty{#2}{\SKV@err{Empty argument for dimension '#1'}\@ehc}{}%
-  \SKV@ifundef{#1}{%
-    \newdimen#1\global#1=\dimexpr#2\relax
-  }{%
-    \global#1=\dimexpr#2\relax
-  }%
+\SKV@newlet\switchtrue\switchon
+\SKV@def*\switchoff#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsundef{if#1}{\SKV@noswerr{#1}}{\@nameuse{#1false}}%
 }
-\SKV@pdef*\SKV@dimnamegdef#1{\SKV@aftercsname\SKV@dimgdef{#1}}
-\SKV@pdef*\define@compboolkeys{%
-  \let\SKV@def@boolkey\define@boolkey
-  \SKV@testopt{\SKV@compbool@opta}{KV}%
+\SKV@newlet\switchfalse\switchoff
+\SKV@def*\ifswitchon#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsundef{if#1}{\SKV@noswerr{#1}\@gobbletwo}%
+    {\@nameuse{@\@nameuse{if#1}first\else second\fi oftwo}}%
 }
-\SKV@pdef*\newcompboolkeys{%
-  \let\SKV@def@boolkey\newboolkey
-  \SKV@testopt{\SKV@compbool@opta}{KV}%
-}
-\SKV@def*\SKV@compbool@opta[#1]#2{%
-  \SKV@testopt{\SKV@define@compboolkeys[#1]{#2}}{mp@}}
-\SKV@def\SKV@define@compboolkeys[#1]#2[#3]#4[#5]#6#7#8{%
-  \SKV@namedef{#1@#2@#4@func}{%
-    #7\SKV@nameuse{if#3#4}\SKV@nameuse{#3#6false}\else
-      \SKV@nameuse{#3#6true}\fi}%
-  \SKV@namedef{#1@#2@#6@func}{%
-    #8\SKV@nameuse{if#3#6}\SKV@nameuse{#3#4false}\else
-      \SKV@nameuse{#3#4true}\fi}%
-  \begingroup\protected@edef\SKV@tempa{\endgroup
-    \unexpanded{%
-      \SKV@def@boolkey+[#1]{#2}[#3]{#4}[#5]{%
-          \SKV@nameuse{#1@#2@#4@func}%
-        }{%
-          \SKV@inputerr{##1}{#4}%
-        }%
-      \SKV@def@boolkey+[#1]{#2}[#3]{#6}[#5]{%
-          \SKV@nameuse{#1@#2@#6@func}%
-        }{%
-          \SKV@inputerr{##1}{#6}%
-        }%
-    }%
-  }%
-  \SKV@tempa
+\SKV@newlet\ifswitchtrue\ifswitchon
+\SKV@def*\ifswitchoff#1{%
+  \SKV@ensurenoscape{#1}%
+  \SKV@ifcsundef{if#1}{\SKV@noswerr{#1}\@gobbletwo}%
+    {\@nameuse{@\@nameuse{if#1}second\else first\fi oftwo}}%
 }
-\SKV@def\SKV@star@or@long#1{%
-  \SKV@ifstar{%
-    \let\l@ngrel@x\relax
-    \def\SKV@star@or@none{*}#1%
-  }{%
-    \let\l@ngrel@x\long
-    \def\SKV@star@or@none{}#1%
-  }%
+\SKV@newlet\ifswitchfalse\ifswitchoff
+\SKV@pdef*\SKV@noswerr#1{%
+  \SKV@err{Switch '\string#1' is undefined}%
+  {You need to first define the switch '\string#1'.}%
 }
-\SKV@pdef\requirecmd{\SKV@star@or@long\SKV@require@cmd}
-\SKV@def\SKV@require@cmd#1{%
-  \ifdefined#1%
-    \SKV@afterelsefi
-    \expandafter\CheckCommand\SKV@star@or@none
-  \else
-    \SKV@afterfi
-    \expandafter\newcommand\SKV@star@or@none
-  \fi
-  {#1}%
+\SKV@def*\SKV@swvalerr#1#2{%
+  \SKV@err{Invalid switch value '#2' for switch '\string#1'}%
+    {Valid switch values are 'true', 'on', 'false', and 'off'.}%
 }
-\def\@check@eq#1#2{%
-  \unless\ifx#1#2%
-    \SKV@warn{%
-      Previous definition of \string#1\MessageBreak
-      doesn't match your new definition.\MessageBreak
-      *** I haven't redefined \string#1\space ***
-    }%
-  \fi
-}
-\SKV@pdef*\SKV@undeftoggle@err#1{%
+\SKV@pdef*\SKV@undeftog@err#1{%
   \SKV@err{Toggle '#1' undefined}%
     {You need to first define '#1' before use.}%
 }
 \SKV@pdef*\deftog#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \SKV@warn{Toggle '#1' redefined\on@line}%
-  }{}%
-  \nameletcs{SKV@toggle@#1}\@secondoftwo
+  \SKV@ifcsundef{SKV@toggle@#1}{}{%
+    \SKV@vbsmsg{warn}{Toggle '#1' redefined\on@line}%
+  }%
+  \SKV@aftercs\let{SKV@toggle@#1}\@secondoftwo
 }
 \SKV@pdef*\newtog#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
     \SKV@err{Toggle '#1' already defined}%
       {Please provide a new toggle or redefine '#1'.}%
-  }{%
-    \nameletcs{SKV@toggle@#1}\@secondoftwo
-  }%
+  }{\SKV@aftercs\let{SKV@toggle@#1}\@secondoftwo}%
 }
 \SKV@pdef*\providetog#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \SKV@info{Toggle '#1' already defined.\MessageBreak
-      Not redefined\on@line}%
-  }{%
-    \nameletcs{SKV@toggle@#1}\@secondoftwo
-  }%
-}
-\SKV@pdef*\requiretog#1{%
-  \SKV@aftercsname\requirecmd{SKV@toggle@#1}[2]{##2}%
-}
-\SKV@pdef*\settog#1#2{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \SKV@ifnamedef{SKV@t@ggle#2}{%
-      \nameletname{SKV@toggle@#1}{SKV@t@ggle#2}%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
+    \SKV@vbsmsg{info}%
+      {Toggle '#1' already defined.\SKV@MB Not redefined\on@line}%
+  }{\SKV@aftercs\let{SKV@toggle@#1}\@secondoftwo}%
+}
+\SKV@pdef*\requiretog#1{\SKV@aftercs\requirecmd{SKV@toggle@#1}[2]{##2}}
+\SKV@def*\settog#1#2{%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
+    \SKV@ifcsdef{SKV@t@ggle#2}{%
+      \SKV@aftercs\let{SKV@toggle@#1\expandafter}%
+        \csname SKV@t@ggle#2\endcsname
     }{%
-      \SKV@err{%
-        Inadmissible value '#2' for toggle '#1'
-      }{%
-        Valid values for toggles are 'true' and 'false'.
-      }%
+      \SKV@err{Inadmissible value '#2' for toggle '#1'}%
+        {Valid values for toggles are 'true' and 'false'.}%
     }%
-  }{%
-    \SKV@undeftoggle@err{#1}%
-  }%
+  }{\SKV@undeftog@err{#1}}%
 }
-\SKV@pdef*\togtrue#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \nameletcs{SKV@toggle@#1}\SKV@t@ggletrue
-  }{%
-    \SKV@undeftoggle@err{#1}%
-  }%
+\SKV@def*\togtrue#1{%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
+    \expandafter\let\csname SKV@toggle@#1\endcsname\SKV@t@ggletrue
+  }{\SKV@undeftog@err{#1}}%
 }
-\SKV@pdef*\togfalse#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \nameletcs{SKV@toggle@#1}\SKV@t@gglefalse
+\SKV@def*\togfalse#1{%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
+    \expandafter\let\csname SKV@toggle@#1\endcsname\SKV@t@gglefalse
   }{%
-    \SKV@undeftoggle@err{#1}%
+    \SKV@undeftog@err{#1}%
   }%
 }
 \SKV@newlet\SKV@t@ggletrue\@firstoftwo
 \SKV@newlet\SKV@t@gglefalse\@secondoftwo
-\SKV@pdef*\iftog#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \@nameuse{SKV@toggle@#1}%
-  }{%
-    \SKV@undeftoggle@err{#1}%
-  }%
+\SKV@def*\iftog#1{%
+  \SKV@ifcsdef{SKV@toggle@#1}{\@nameuse{SKV@toggle@#1}}%
+    {\SKV@undeftog@err{#1}}%
+}
+\SKV@def*\ifnottog#1{%
+  \SKV@ifcsdef{SKV@toggle@#1}{%
+    \@nameuse{SKV@toggle@#1}\@secondoftwo\@firstoftwo}%
+      {\SKV@undeftog@err{#1}\@gobbletwo}%
+}
+\deftog{pdf}
+\SKV@ifundef\pdfoutput{}{%
+  \ifnum\pdfoutput<\@ne
+    \SKV@pdef*\SKV@ifpdf{\@secondoftwo}%
+  \else
+    \togtrue{pdf}%
+    \SKV@pdef*\SKV@ifpdf{\@firstoftwo}%
+  \fi
+  \SKV@pdef*\SKV@ifnotpdf{\SKV@ifpdf\@secondoftwo\@firstoftwo}%
 }
-\SKV@pdef*\ifnottog#1{%
-  \SKV@ifnamedef{SKV@toggle@#1}{%
-    \@nameuse{SKV@toggle@#1}\@secondoftwo\@firstoftwo
-  }{%
-    \SKV@undeftoggle@err{#1}\@gobbletwo
-  }%
+\SKV@ifundef\ifnotpdf
+  {\let\ifnotpdf\SKV@ifnotpdf}%
+  {\SKV@vbsmsg{info}{\SKV@useinfo{ifnotpdf}}}
+\SKV@AtDocumentStart{%
+  \SKV@ifundef\ifpdf
+    {\SKV@pdef*\ifpdf{\SKV@ifpdf}}%
+    {\SKV@vbsmsg{info}{\SKV@useinfo{ifpdf}}}%
 }
 \SKV@pdef*\SKV@definedkey@err#1{%
-  \SKV@ifnamedef{\XKV@header#1}{%
-    \SKV@err{%
-      Key '#1' already defined in family '\XKV@tfam'
-    }{%
-      Use another key name for '#1'.
-    }%
-  }{}%
+  \SKV@ifcsundef{\XKV@header#1}{}{%
+    \SKV@err{Key '#1' already defined in family '\XKV@tfam'\SKV@MB
+      with prefix '\SKV@pref'}{Use another key name instead of '#1'.}%
+  }%
 }
+\SKV@pdef*\define@menukey{\define@choicekey}
 \SKV@pdef*\define@togkey{\XKV@t@stopta{\XKV@testoptd\SKV@define@togkey{}}}
 \SKV@def*\SKV@define@togkey#1#2[#3]{%
-  \SKV@reservedkey@err{#2}%
-  \SKV@suspendedkey@err{#2}%
+  \SKV@findkeypointers{#2}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+    \SKV@csundef{SKV@toggle@#1\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
   \ifXKV@pl
-    \SKV@afterelsefi
-    \expandafter\SKV@d@f@ne@togkey
+    \def\SKV@n@xt{\SKV@aftercs\SKV@d@f@ne@togkey}%
   \else
-    \SKV@afterfi
-    \expandafter\SKV@d@fine@togkey
+    \def\SKV@n@xt{\SKV@aftercs\SKV@d@fine@togkey}%
   \fi
-  \csname\XKV@header#2\endcsname{#2}{#1#2}{#3}%
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    {\XKV@header\SKV@resa}{\SKV@resa}{#1\SKV@resa}{#3}}%
+  \aftergroup\SKV@n@xt\SKV@tempa
 }
 \SKV@def*\SKV@d@fine@togkey#1#2#3#4#5{%
-  \SKV@d@f@ne@t@gkey#1{#2}{#3}{#4}%
-  {{\settog{#3}{\XKV@resa}#5}}%
+  \SKV@d@f@ne@t@gkey#1{#2}{#3}{#4}{{\settog{#3}{\XKV@resa}#5}}%
 }
 \SKV@def*\SKV@d@f@ne@togkey#1#2#3#4#5#6{%
   \SKV@d@f@ne@t@gkey#1{#2}{#3}{#4}%
@@ -783,367 +1581,651 @@
     }%
   \fi
 }
-\SKV@pdef*\define@togkeys{%
-  \XKV@plfalse\XKV@testoptd\SKV@define@togkeys{}}
+\SKV@pdef*\define@togkeys{\XKV@plfalse\XKV@testoptd\SKV@define@togkeys{}}
 \SKV@def*\SKV@define@togkeys#1#2[#3]{%
-  \XKV@sp@deflist\SKV@tempa{#2}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@expandargs{3}\SKV@d@fine@togkeys{{\SKV@tempa}}{{#1}{#3}}\SKV@nil
+  \SKV@despacelist{#2}%
+  \SKV@for*[,]\SKV@resa\SKV@tempa{%
+    \SKV@expargs{3}%
+      \SKV@d@fine@togkeys{{\SKV@tempa}}{{#1}{#3}}\@nil
   }%
 }
 \SKV@def*\SKV@d@fine@togkeys#1#2#3{%
-  \SKV@aftercsname\SKV@d@f@ne@t@gkey{\XKV@header#1}%
-    {#1}{#2#1}{#3}{{\settog{#2#1}{\XKV@resa}}}%
+  \SKV@findkeypointers{#1}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+    \SKV@csundef{SKV@toggle@#2\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
+  \edef\SKV@tempa{%
+    \noexpand\SKV@d@f@ne@t@gkey\@nameuse{\XKV@header\SKV@resa}%
+      {\SKV@resa}{#2\SKV@resa}{#3}%
+      {{\noexpand\settog{#2\SKV@resa}{\noexpand\XKV@resa}}}%
+  }%
+  \SKV@tempa
 }
 \SKV@pdef*\newordkey{\XKV@testoptb\SKV@newordkey}
 \SKV@def*\SKV@newordkey#1{%
-  \SKV@definedkey@err{#1}%
-  \SKV@ifnextchar[{\XKV@d@fine@k@y{#1}}%
-    {\SKV@namedef{\XKV@header#1}####1}%
+  \SKV@findkeypointers{#1}%
+  \SKV@expnext\SKV@definedkey@err\SKV@resa
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    \SKV@ifbrack{\noexpand\XKV@d@fine@key{\SKV@resa}}%
+      {\noexpand\SKV@d@fine@key{\SKV@resa}}%
+  }%
+  \SKV@tempa
 }
 \SKV@pdef*\newcmdkey{\XKV@testoptd\SKV@newcmdkey{cmd}}
 \SKV@def*\SKV@newcmdkey#1#2[#3]#4{%
-  \SKV@definedkey@err{#2}%
-  \ifXKV@st\XKV@define@default{#2}{#3}\fi
-  \edef\SKV@tempa{\noexpand\def\@nameuse{\XKV@header#2}####1}%
-  \edef\SKV@tempb{\noexpand\def\@nameuse{#1#2}\unexpanded{{##1}#4}}%
-  \expandafter\SKV@tempa\expandafter{\SKV@tempb}%
-  \SKV@undef\SKV@tempa\SKV@undef\SKV@tempb
+  \SKV@findkeypointers{#2}%
+  \SKV@expnext\SKV@definedkey@err\SKV@resa
+  \ifXKV@st
+    \SKV@afterfi
+    \SKV@expnext\XKV@define@default\SKV@resa{#3}%
+  \fi
+  \begingroup
+  \edef\SKV@tempa{\noexpand\def\@nameuse{\XKV@header\SKV@resa}####1}%
+  \edef\SKV@tempb{\noexpand\def\@nameuse{#1\SKV@resa}%
+    \unexpanded{{##1}#4}}%
+  \expandafter\expandafter\expandafter\endgroup
+    \expandafter\SKV@tempa\expandafter{\SKV@tempb}%
 }
 \SKV@pdef*\newcmdkeys{\XKV@testoptd\SKV@newcmdkeys{cmd}}
 \SKV@def*\SKV@newcmdkeys#1#2[#3]{%
-  \XKV@sp@deflist\SKV@tempa{#2}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
+  \SKV@despacelist{#2}%
+  \SKV@for*[,]\SKV@resa\SKV@tempa{%
     \edef\SKV@tempa{\noexpand\SKV@newcmdkey{#1}{\SKV@tempa}}%
     \SKV@tempa[#3]{}%
   }%
 }
 \SKV@pdef*\newchoicekey{\XKV@testopta{\XKV@testoptb\SKV@newchoicekey}}
 \SKV@def*\SKV@newchoicekey#1{%
-  \SKV@definedkey@err{#1}%
-  \@testopt{\XKV@d@fine@choicekey{#1}}{}%
+  \SKV@findkeypointers{#1}%
+  \SKV@expnext\SKV@definedkey@err\SKV@resa
+  \begingroup
+  \edef\SKV@tempa##1{\endgroup\SKV@testopt{##1{\SKV@resa}}{}}%
+  \SKV@tempa\XKV@d@fine@choicekey
 }
+\let\newmenukey\newchoicekey
 \SKV@pdef*\newboolkey{\XKV@t@stopta{\XKV@testoptd\SKV@newboolkey{}}}
 \SKV@def*\SKV@newboolkey#1#2[#3]{%
-  \SKV@definedkey@err{#2}%
+  \SKV@findkeypointers{#2}%
+  \SKV@expnext\SKV@definedkey@err\SKV@resa
   \ifXKV@pl
-    \SKV@afterelsefi
-    \expandafter\XKV@d@f@ne@boolkey
+    \def\SKV@n@xt{\SKV@aftercs\XKV@d@f@ne@boolkey}%
   \else
-    \SKV@afterfi
-    \expandafter\XKV@d@fine@boolkey
+    \def\SKV@n@xt{\SKV@aftercs\XKV@d@fine@boolkey}%
   \fi
-  \csname\XKV@header#2\endcsname{#2}{#1#2}{#3}%
+  \edef\SKV@tempa{{\XKV@header\SKV@resa}{\SKV@resa}{#1\SKV@resa}{#3}}%
+  \expandafter\SKV@n@xt\SKV@tempa
 }
 \SKV@pdef*\newboolkeys{\XKV@plfalse\XKV@testoptd\SKV@newboolkeys{}}
 \SKV@def*\SKV@newboolkeys#1#2[#3]{%
-  \XKV@sp@deflist\SKV@tempa{#2}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
+  \SKV@despacelist{#2}%
+  \SKV@for*[,]\SKV@resa\SKV@tempa{%
     \SKV@definedkey@err\SKV@tempa
-    \SKV@expandargs{3}\XKV@d@fine@boolkeys{{\SKV@tempa}}{{#1}{#3}}\SKV@nil
+    \SKV@expargs{3}%
+      \XKV@d@fine@boolkeys{{\SKV@tempa}}{{#1}{#3}}\@nil
   }%
 }
 \SKV@pdef*\newtogkey{\XKV@t@stopta{\XKV@testoptd\SKV@newtogkey{}}}
 \SKV@def*\SKV@newtogkey#1#2[#3]{%
-  \SKV@definedkey@err{#2}%
+  \SKV@findkeypointers{#2}%
+  \SKV@expnext\SKV@definedkey@err\SKV@resa
   \ifXKV@pl
-    \SKV@afterelsefi
-    \expandafter\SKV@d@f@ne@togkey
+    \def\SKV@n@xt{\SKV@aftercs\SKV@d@f@ne@togkey}%
   \else
-    \SKV@afterfi
-    \expandafter\SKV@d@fine@togkey
+    \def\SKV@n@xt{\SKV@aftercs\SKV@d@fine@togkey}%
   \fi
-  \csname\XKV@header#2\endcsname{#2}{#1#2}{#3}%
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    {\XKV@header\SKV@resa}{\SKV@resa}{#1\SKV@resa}{#3}}%
+  \aftergroup\SKV@n@xt\SKV@tempa
 }
 \SKV@pdef*\newtogkeys{\XKV@plfalse\XKV@testoptd\SKV@newtogkeys{}}
 \SKV@def*\SKV@newtogkeys#1#2[#3]{%
-  \XKV@sp@deflist\SKV@tempa{#2}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
+  \SKV@despacelist{#2}%
+  \SKV@for*[,]\SKV@resa\SKV@tempa{%
     \SKV@definedkey@err\SKV@tempa
-    \SKV@expandargs{3}\SKV@d@fine@togkeys{{\SKV@tempa}}{{#1}{#3}}\SKV@nil
+    \SKV@expargs{3}\SKV@d@fine@togkeys{{\SKV@tempa}}{{#1}{#3}}\@nil
+  }%
+}
+\SKV@pdef*\define@biboolkeys{\SKV@compopta\define@boolkey\SKV@biboolkeys}
+\SKV@pdef*\newbiboolkeys{\SKV@compopta\newboolkey\SKV@biboolkeys}
+\SKV@pdef*\define@uniboolkeys{\SKV@compopta\define@boolkey\SKV@uniboolkeys}
+\SKV@pdef*\newuniboolkeys{\SKV@compopta\newboolkey\SKV@uniboolkeys}
+\SKV@pdef*\define@biuniboolkeys{%
+  \SKV@savstate
+  \SKV@t@stoptb{\SKV@compopta\define@boolkey\SKV@biuniboolkeys}%
+}
+\SKV@pdef*\newbiuniboolkeys{%
+  \SKV@savstate
+  \SKV@t@stoptb{\SKV@compopta\newboolkey\SKV@biuniboolkeys}%
+}
+\SKV@pdef*\define@bitogkeys{\SKV@compopta\define@togkey\SKV@bitogkeys}
+\SKV@pdef*\newbitogkeys{\SKV@compopta\newtogkey\SKV@bitogkeys}
+\SKV@pdef*\define@unitogkeys{\SKV@compopta\define@togkey\SKV@unitogkeys}
+\SKV@pdef*\newunitogkeys{\SKV@compopta\newtogkey\SKV@unitogkeys}
+\SKV@pdef*\define@biunitogkeys{%
+  \SKV@savstate
+  \SKV@t@stoptb{\SKV@compopta\define@togkey\SKV@biunitogkeys}%
+}
+\SKV@pdef*\newbiunitogkeys{%
+  \SKV@savstate
+  \SKV@t@stoptb{\SKV@compopta\newtogkey\SKV@biunitogkeys}%
+}
+\SKV@def*\SKV@compopta#1#2{%
+  \let\SKV@c@mpkey#1\let\SKV@co@pkey#2%
+  \SKV@testopt{\SKV@compoptb}{KV}%
+}
+\SKV@def*\SKV@compoptb[#1]#2{\SKV@testopt{\SKV@compoptc[#1]{#2}}{mp@}}
+\SKV@def*\SKV@compoptc[#1]#2[#3]#4{%
+  \SKV@testopt{\SKV@co@pkey[#1]{#2}[#3]{#4}}{true}}
+\SKV@def*\SKV@biboolkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \@namedef{#1@#2@#4@func}{%
+    #7\relax
+    \ifswitchon{#3#4}{\switchoff{#3#6}}{\switchon{#3#6}#8\relax}%
+  }%
+  \@namedef{#1@#2@#6@func}{%
+    #8\relax
+    \ifswitchon{#3#6}{\switchoff{#3#4}}{\switchon{#3#4}#7\relax}%
+  }%
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
+}
+\SKV@def*\SKV@uniboolkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \@namedef{#1@#2@#4@func}{%
+    #7\relax
+    \ifswitchon{#3#4}{\switchon{#3#6}#8\relax}{\switchoff{#3#6}}%
+  }%
+  \@namedef{#1@#2@#6@func}{%
+    #8\relax
+    \ifswitchon{#3#6}{\switchon{#3#4}#7\relax}{\switchoff{#3#4}}%
+  }%
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
+}
+\SKV@def*\SKV@biuniboolkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \SKV@aftercs\def{#1@#2@#6@func}{#8\relax}%
+  \ifswitchon{SKV@st}{%
+    \ifswitchon{SKV@pl}{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\ifswitchon{#3#4}{}{\switchoff{#3#6}}%
+      }%
+    }{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax
+        \ifswitchon{#3#4}{}{\switchon{#3#6}\@nameuse{#1@#2@#6@func}}%
+      }%
+    }%
+  }{%
+    \ifswitchon{SKV@pl}{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\ifswitchon{#3#4}{\switchoff{#3#6}}{}%
+      }%
+    }{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax
+        \ifswitchon{#3#4}{\switchon{#3#6}\@nameuse{#1@#2@#6@func}}{}%
+      }%
+    }%
   }%
+  \SKV@resstate
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
 }
-\SKV@pdef*\define@comptogkeys{%
-  \let\SKV@def@togkey\define@togkey
-  \SKV@testopt{\SKV@comptog@opta}{KV}%
+\SKV@def*\SKV@bitogkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \@namedef{#1@#2@#4@func}{%
+    #7\relax
+    \iftog{#3#4}{\togfalse{#3#6}}{\togtrue{#3#6}#8\relax}%
+  }%
+  \@namedef{#1@#2@#6@func}{%
+    #8\relax
+    \iftog{#3#6}{\togfalse{#3#4}}{\togtrue{#3#4}#7\relax}%
+  }%
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
 }
-\SKV@pdef*\newcomptogkeys{%
-  \let\SKV@def@togkey\newtogkey
-  \SKV@testopt{\SKV@comptog@opta}{KV}%
-}
-\SKV@def*\SKV@comptog@opta[#1]#2{%
-  \SKV@testopt{\SKV@define@comptogkeys[#1]{#2}}{mp@}}
-\SKV@def\SKV@define@comptogkeys[#1]#2[#3]#4[#5]#6#7#8{%
-  \SKV@namedef{#1@#2@#4@func}{%
-    #7\iftog{#3#4}{\togfalse{#3#6}}{\togtrue{#3#6}}}%
-  \SKV@namedef{#1@#2@#6@func}{%
-    #8\iftog{#3#6}{\togfalse{#3#4}}{\togtrue{#3#4}}}%
-  \begingroup\protected@edef\SKV@tempa{\endgroup
-    \unexpanded{%
-      \SKV@def@togkey+[#1]{#2}[#3]{#4}[#5]{%
-        \SKV@nameuse{#1@#2@#4@func}%
-      }{%
-        \SKV@inputerr{##1}{#4}%
+\SKV@def*\SKV@unitogkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \@namedef{#1@#2@#4@func}{%
+    #7\relax
+    \iftog{#3#4}{\togtrue{#3#6}#8\relax}{\togfalse{#3#6}}%
+  }%
+  \@namedef{#1@#2@#6@func}{%
+    #8\relax
+    \iftog{#3#6}{\togtrue{#3#4}#7\relax}{\togfalse{#3#4}}%
+  }%
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
+}
+\SKV@def*\SKV@biunitogkeys[#1]#2[#3]#4[#5]#6#7#8{%
+  \@namedef{#1@#2@#6@func}{#8}%
+  \ifswitchon{SKV@st}{%
+    \ifswitchon{SKV@pl}{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\ifnottog{#3#4}{\togfalse{#3#6}}{}%
       }%
-      \SKV@def@togkey+[#1]{#2}[#3]{#6}[#5]{%
-        \SKV@nameuse{#1@#2@#6@func}%
-      }{%
-        \SKV@inputerr{##1}{#6}%
+    }{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\ifnottog{#3#4}{\togtrue{#3#6}#8\relax}{}%
+      }%
+    }%
+  }{%
+    \ifswitchon{SKV@pl}{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\iftog{#3#4}{\togfalse{#3#6}}{}%
+      }%
+    }{%
+      \@namedef{#1@#2@#4@func}{%
+        #7\relax\iftog{#3#4}{\togtrue{#3#6}#8\relax}{}%
       }%
     }%
   }%
-  \SKV@tempa
+  \SKV@resstate
+  \SKV@compk@y{#1}{#2}{#3}{#4}{#5}{#6}%
+}
+\SKV@def*\SKV@compk@y#1#2#3#4#5#6{%
+  \SKV@c@mpkey+[#1]{#2}[#3]{#4}[#5]{\@nameuse{#1@#2@#4@func}}%
+    {\SKV@inputerr{##1}{#4}}%
+  \SKV@c@mpkey+[#1]{#2}[#3]{#6}[#5]{\@nameuse{#1@#2@#6@func}}%
+    {\SKV@inputerr{##1}{#6}}%
+}
+\SKV@pdef*\SKV@keylistrema#1\@nil#2{%
+  \long\edef\SKV@remainder{\unexpanded{#1}}%
+  \SKV@oifblank{\SKV@remainder}{}{%
+    \def\SKV@tempa##1#2\@nil{\def\SKV@remainder{##1}}%
+    \expandafter\SKV@tempa\SKV@remainder\@nil
+  }%
 }
-\SKV@pdef*\stopread#1\SKV@nil{\long\edef\SKV@remainder{\unexpanded{#1}}}
-\def\SKV@noa{\z@}\def\SKV@nob{\z@}\def\SKV@noc{\z@}
 \SKV@pdef*\define@keylist{%
-  \let\SKV@def@key\define@key
+  \let\SKV@def@ordkey\define@key
   \let\SKV@def@cmdkey\define@cmdkey
   \let\SKV@def@boolkey\define@boolkey
   \let\SKV@def@togkey\define@togkey
   \let\SKV@def@choicekey\define@choicekey
-  \SKV@ifstar{\XKV@sttrue\SKV@define@keylist}%
-    {\XKV@stfalse\SKV@define@keylist}%
+  \SKV@savstate
+  \SKV@t@stopta\SKV@define@keylist
 }
 \SKV@pdef*\newkeylist{%
-  \let\SKV@def@key\newordkey
+  \let\SKV@def@ordkey\newordkey
   \let\SKV@def@cmdkey\newcmdkey
   \let\SKV@def@boolkey\newboolkey
   \let\SKV@def@togkey\newtogkey
   \let\SKV@def@choicekey\newchoicekey
-  \SKV@ifstar{\XKV@sttrue\SKV@define@keylist}%
-    {\XKV@stfalse\SKV@define@keylist}%
-}
-\SKV@def\ChoiceKeyValues#1#2{%
-  \ifSKV@xchoicelist
-    \SKV@nameedef{\SKV@keyprefix @\SKV@keyfamily @#1@altlist}{#2}%
+  \SKV@savstate
+  \SKV@t@stopta\SKV@define@keylist
+}
+\SKV@def*\choicekeyvalues{%
+  \SKV@t@stopta{\SKV@testopt\SKV@choic@keyvalues\SKV@keyprefix}}
+\SKV@def*\SKV@choic@keyvalues[#1]{%
+  \SKV@testopt{\SKV@choic@keyv@lues[#1]}\SKV@keyfamily}
+\SKV@def*\SKV@choic@keyv@lues[#1][#2]#3#4{%
+  \ifSKV@st
+    \SKV@csedef{#1@#2@#3@altlist}{#4}%
   \else
-    \SKV@ifnameundef{\SKV@keyprefix @\SKV@keyfamily @#1@altlist}{%
-      \SKV@newnameedef{\SKV@keyprefix @\SKV@keyfamily @#1@altlist}{#2}%
+    \SKV@ifcsundef{#1@#2@#3@altlist}{%
+      \SKV@csedef{#1@#2@#3@altlist}{#4}%
     }{%
-      \SKV@err{%
-        You have attempted to set two \MessageBreak
-        \string\ChoiceKeyValues\space for the choice\MessageBreak
-        key '#1' in the same family '\SKV@keyfamily'
-      }{%
-        You can only do that if you set 'xchoicelist'=true.
-      }%
+      \SKV@err
+        {Problem with \string\choicekeyvalues\space for key '#3'}%
+        {You have attempted to set two \string\choicekeyvalues\SKV@MB
+        for choice key '#3' in the same family '#2'\SKV@MB
+        with the same prefix '#1'. You can only do\SKV@MB 
+        that if you use the starred variant of \string\choicekeyvalues.}%
     }%
   \fi
 }
-\SKV@newlet\CKVS\ChoiceKeyValues
+\SKV@newlet\CKVS\choicekeyvalues
 \SKV@def*\SKV@detok@z@p#1{%
-  \edef#1{\expandafter\detokenize\expandafter{#1}\space}%
+  \edef#1{\detokenize\expandafter{#1}\space}%
   \edef#1{\expandafter\zap@space#1\@empty}%
 }
 \SKV@def*\SKV@detok@zsp#1{%
+  \SKV@ensurescape{#1}%
   \begingroup
-  \def\SKV@no{\z@}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b#1\SKV@tempa{%
-    \edef\SKV@no{\the\numexpr\SKV@no+\@ne}%
-    \edef\SKV@tempa{\expandafter\detokenize\expandafter{\SKV@tempa}\space}%
+  \SKV@for*[,]#1\SKV@tempa{%
+    \edef\SKV@tempa{\detokenize\expandafter{\SKV@tempa}\space}%
     \edef\SKV@tempa{\expandafter\zap@space\SKV@tempa\@empty}%
-    \SKV@namexdef{SKV@zsp\SKV@no}{\SKV@expandox{\SKV@tempa}}%
+    \SKV@aftercs\xdef{SKV@zsp@\expandafter
+      \@gobble\SKV@tempa}{\SKV@expox{\SKV@tempa}}%
   }%
   \endgroup
 }
 \SKV@def*\SKV@detok@dsp#1{%
+  \SKV@ensurescape{#1}%
   \begingroup
-  \def\SKV@no{\z@}%
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b#1\SKV@tempa{%
-    \edef\SKV@no{\the\numexpr\SKV@no+\@ne}%
-    \edef\SKV@tempa{\expandafter\detokenize\expandafter{\SKV@tempa}}%
-    \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-    \SKV@namexdef{SKV@dsp\SKV@no}{\SKV@expandox{\SKV@tempa}}%
+  \SKV@for*[,]#1\SKV@tempa{%
+    \edef\SKV@tempa{\detokenize\expandafter{\SKV@tempa}}%
+    \SKV@despace\SKV@tempa
+    \SKV@aftercs\xdef{SKV@dsp@\expandafter
+      \@gobble\SKV@tempa}{\SKV@expox{\SKV@tempa}}%
   }%
   \endgroup
 }
-\SKV@def*\SKV@if@err{%
-  \SKV@err{You can't use '\protect\if' and '\protect\fi' in key macro}%
-    {Use '\protect\fif' and '\protect\ffi' instead.}%
-}
-\SKV@def\SKV@define@mult@keys#1,#2,#3,#4\SKV@nil{%
+\SKV@def*\SKV@exceplist{\par,\if,\ifcase,\or,\else,\skif,\iftog,\ifswitch}
+\SKV@detok@dsp\SKV@exceplist
+\SKV@def*\SKV@noiferr#1#2{%
+  \SKV@err{You can't use '\@backslashchar #1' in key macro within keylist}%
+  {Use '\@backslashchar #2' instead of '\@backslashchar #1'.}%
+}
+\SKV@def\SKV@define@multkeys#1,#2,#3,#4\@nil{%
+  \let\SKV@altlisterr\z@
+  \SKV@trailead{#1}\SKV@tempa
+  \SKV@checkchoice{\SKV@tempa}{ord,cmd,bool,tog,choice,menu}{%
+    \edef\SKV@keytype{\the\numexpr\nr+1}%
+  }{%
+    \SKV@checkchoice{\SKV@tempa}{1,2,3,4,5}{%
+      \edef\SKV@keytype{\the\numexpr\nr+1}%
+    }{%
+      \SKV@err{Unknown key type/identifier '\string#1'}%
+      {Valid key types are 'ord', 'cmd', 'bool', 'tog',
+        'choice', 'menu'\SKV@MB and '1', '2', '3', '4', '5'}%
+    }%
+  }%
+  \SKV@ifnotempty{#2}{}{%
+    \SKV@err{No key name specified for key type '\string#1'}%
+      {\string\define@keylist: key name required for all keys}%
+  }%
   \begingroup
   \SKV@ifblank{#4}{}{%
-    \def\SKV@tempa{\if,\fi,\fif}%
-    \SKV@detok@dsp\SKV@tempa
-    \def\SKV@tempb{#4}\SKV@detok@z@p\SKV@tempb
-    \@expandtwoargs\in@{\@nameuse{SKV@dsp1}}\SKV@tempb
-    \ifin@\SKV@afterfi\SKV@if@err\fi
-    \@expandtwoargs\in@{\@nameuse{SKV@dsp3}}\SKV@tempb
+    \edef\SKV@tempb{\detokenize{#4}\space}%
+    \edef\SKV@tempb{\expandafter\zap@space\SKV@tempb\@empty}%
+    \@expandtwoargs\SKV@in@\SKV@dsp@if\SKV@tempb
     \ifin@
-      \SKV@afterelsefi
-      \SKV@namegdef{\SKV@keyprefix @\SKV@keyfamily @#2@func}{#4}%
-    \else
-      \SKV@afterfi
-      \SKV@namexdef{\SKV@keyprefix @\SKV@keyfamily @#2@func}{\SKV@expandox{#4}}%
+      \@expandtwoargs\SKV@in@\SKV@dsp@iftog\SKV@tempb
+      \ifin@\else
+        \@expandtwoargs\SKV@in@\SKV@dsp@ifswitch\SKV@tempb
+        \ifin@\else\SKV@noiferr{if}{skif}\fi
+      \fi
     \fi
+    \@expandtwoargs\SKV@in@\SKV@dsp@par\SKV@tempb
+    \ifin@\SKV@afterfi\SKV@noiferr{par}{endgraf}\fi
+    \@expandtwoargs\SKV@in@\SKV@dsp@ifcase\SKV@tempb
+    \ifin@\SKV@afterfi\SKV@noiferr{ifcase}{skifcase}\fi
+    \@expandtwoargs\SKV@in@\SKV@dsp@or\SKV@tempb
+    \ifin@\SKV@afterfi\SKV@noiferr{or}{skor}\fi
+    \@expandtwoargs\SKV@in@\SKV@dsp@else\SKV@tempb
+    \ifin@\SKV@afterfi\SKV@noiferr{else}{skelse}\fi
   }%
   \protected@edef\SKV@tempa{\endgroup
-    \ifcase#1\relax
-      \def\SKV@noc{\@ne}%
+    \ifcase\SKV@keytype\relax
     \or
-      \noexpand\SKV@def@key[\SKV@keyprefix]{\SKV@keyfamily}%
-        {#2}[#3]{%
-          \noexpand\SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@func}%
-        }%
+      \noexpand\SKV@def@ordkey[\SKV@keyprefix]{\SKV@keyfamily}%
+        {#2}[#3]{\unexpanded{#4}}%
     \or
       \noexpand\SKV@def@cmdkey[\SKV@keyprefix]{\SKV@keyfamily}%
-        [\SKV@macroprefix]{#2}[#3]{%
-          \noexpand\SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@func}%
-        }%
+        [\SKV@macroprefix]{#2}[#3]{\unexpanded{#4}}%
     \or
       \noexpand\SKV@def@boolkey+[\SKV@keyprefix]{\SKV@keyfamily}%
-        [\SKV@macroprefix]{#2}[#3]{%
-          \noexpand\SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@func}%
-        }{%
+        [\SKV@macroprefix]{#2}[#3]{\unexpanded{#4}}{%
           \unexpanded{\SKV@inputerr{##1}{#2}}%
         }%
     \or
       \noexpand\SKV@def@togkey+[\SKV@keyprefix]{\SKV@keyfamily}%
-        [\SKV@macroprefix]{#2}[#3]{%
-          \noexpand\SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@func}%
-        }{%
+        [\SKV@macroprefix]{#2}[#3]{\unexpanded{#4}}{%
           \unexpanded{\SKV@inputerr{##1}{#2}}%
         }%
     \or
-      \SKV@ifnameundef{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}{%
-        \def\SKV@noa{\@ne}%
-      }{}%
+      \SKV@ifcsdef{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}{}%
+        {\let\SKV@altlisterr\@ne}%
       \noexpand\SKV@def@choicekey*+[\SKV@keyprefix]{\SKV@keyfamily}{#2}%
         [\unexpanded{\val\nr}]{%
-          \SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}%
-        }[#3]{%
-          \noexpand\SKV@nameuse{\SKV@keyprefix @\SKV@keyfamily @#2@func}%
-        }{%
-          \unexpanded{\SKV@inputerr{##1}{#2}}%
-        }%
-    \else
-      \def\SKV@noc{\@ne}%
+          \SKV@csuse{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}%
+        }[#3]{\unexpanded{#4}}{\unexpanded{\SKV@inputerr{##1}{#2}}}%
+    \or
+      \SKV@ifcsdef{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}{}%
+        {\let\SKV@altlisterr\@ne}%
+      \noexpand\SKV@def@choicekey*+[\SKV@keyprefix]{\SKV@keyfamily}{#2}%
+        [\unexpanded{\val\nr}]{%
+          \SKV@csuse{\SKV@keyprefix @\SKV@keyfamily @#2@altlist}%
+        }[#3]{\unexpanded{#4}}{\unexpanded{\SKV@inputerr{##1}{#2}}}%
     \fi
   }%
   \SKV@tempa
-  \ifnum\SKV@noa=\@ne
+  \ifnum\SKV@altlisterr=\@ne
     \SKV@afterfi
       \SKV@err{%
-        Choice key '#2' can't be defined.\MessageBreak
+        Choice key '#2' can't be defined.\SKV@MB
         Alternate key values list for '#2' is empty
       }{%
-        You need to first define admissible\MessageBreak
-        key values through '\string\ChoiceKeyValues'\MessageBreak
+        You need to first define admissible\SKV@MB
+        key values through '\string\choicekeyvalues'\SKV@MB
         for choice key '#2'.
       }%
   \fi
-  \ifnum\SKV@noc=\@ne
-    \SKV@afterfi
-      \SKV@err{Unknown key type/identifier '#1'}%
-        {You can only use key types 1 to 5.}%
-  \fi
+}
+\SKV@pdef*\SKV@in@#1#2{%
+  \def\in@@##1#1##2##3\in@@{\ifx\in@##2\in@false\else\in@true\fi}%
+  \in@@#2\@mil#1\in@\in@@
 }
 \SKV@pdef*\in@tog#1#2{%
-  \def\in@@##1#1##2##3\in@@{%
-    \ifx\in@##2\togfalse{in@}\else\togtrue{in@}\fi
-  }%
-  \in@@#2#1\in@\in@@
+  \SKV@in@{#1}{#2}%
+  \ifin@\togtrue{in@}\else\togfalse{in@}\fi
 }
-\newtog{in@}
+\deftog{in@}
 \SKV@pdef*\in@tok#1#2{%
   \begingroup
-  \edef\SKV@tempa{\detokenize{#1}}%
-  \edef\SKV@tempb{\detokenize{#2}}%
-  \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@expandargs{1}\KV@@sp@def\SKV@tempb\SKV@tempb\SKV@nil
-  \SKV@expandargs{3}{\def\in@@##1}\SKV@tempa{%
-    ##2##3\in@@{\global\ifx\in@##2\in@false\else\in@true\fi}%
-  }\SKV@nil
-  \SKV@expandargs{3}\in@@{\SKV@tempb\SKV@tempa}{\in@\in@@}\SKV@nil
+  \SKV@expnext\SKV@trailead{\detokenize{#1}}\SKV@tempa
+  \SKV@expnext\SKV@trailead{\detokenize{#2}}\SKV@tempb
+  \@expandtwoargs\SKV@in@\SKV@tempa\SKV@tempb
+  \global\let\ifin@\ifin@
   \endgroup
 }
 \def\XKV@makepf#1{%
-  \KV@@sp@def\XKV@prefix{#1}%
-  \SKV@expandargs{3}\XKV@checksanitizeb{{\SKV@rkpnames}}\SKV@tempa\SKV@nil
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \XKV@knftrue
-  \XKV@whilist\SKV@tempa\SKV@tempa\ifXKV@knf\fi{%
-    \ifx\XKV@prefix\SKV@tempa\XKV@knffalse\fi
-  }%
-  \unless\ifXKV@knf
-    \SKV@afterfi
-    \SKV@err{Prefix '\SKV@tempa' is not allowed}%
-      {Use another prefix instead of '\SKV@tempa'}%
+  \SKV@trailead{#1}\XKV@prefix
+  \ifSKV@sk\else
+    \SKV@expnext\XKV@checksanitizeb\SKV@rkpnames\SKV@tempa
+    \SKV@despacelist*\SKV@tempa
+    \XKV@knftrue
+    \XKV@whilist\SKV@tempa\SKV@tempa\ifXKV@knf\fi{%
+      \ifx\XKV@prefix\SKV@tempa\XKV@knffalse\fi
+    }%
+    \unless\ifXKV@knf
+      \SKV@afterfi
+      \SKV@err{Prefix '\SKV@tempa' is reserved}%
+        {Use another prefix name instead of '\SKV@tempa'.}%
+    \fi
   \fi
   \edef\SKV@pref{\ifx\XKV@prefix\@empty\else\XKV@prefix\fi}%
   \edef\XKV@prefix{\ifx\XKV@prefix\@empty\else\XKV@prefix @\fi}%
 }
 \def\XKV@makehd#1{%
-  \SKV@expandargs{1}\KV@@sp@def\XKV@header{#1}\SKV@nil
-  \SKV@expandargs{3}\XKV@checksanitizeb{{\SKV@rfnames}}\SKV@tempa\SKV@nil
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \XKV@knftrue
-  \XKV@whilist\SKV@tempa\SKV@tempa\ifXKV@knf\fi{%
-    \ifx\XKV@header\SKV@tempa\XKV@knffalse\fi
-  }%
-  \unless\ifXKV@knf
-    \SKV@afterfi
-    \SKV@err{Family '\SKV@tempa' is not allowed}%
-      {Use another family instead of '\SKV@tempa'}%
+  \SKV@expargs{3}\SKV@trailead{{#1}}\XKV@header\@nil
+  \ifSKV@sk\else
+    \SKV@expnext\XKV@checksanitizeb\SKV@rfnames\SKV@tempa
+    \SKV@despacelist*\SKV@tempa
+    \XKV@knftrue
+    \XKV@whilist\SKV@tempa\SKV@tempa\ifXKV@knf\fi{%
+      \ifx\XKV@header\SKV@tempa\XKV@knffalse\fi
+    }%
+    \unless\ifXKV@knf
+      \SKV@afterfi
+      \SKV@err{Family '\SKV@tempa' is reserved}%
+        {Use another family name instead of '\SKV@tempa'.}%
+    \fi
   \fi
   \edef\XKV@header{%
     \XKV@prefix\ifx\XKV@header\@empty\else\XKV@header @\fi}%
 }
+\SKV@def*\SKV@resolvekey#1#2\@nil#3{%
+  \def\SKV@resolve##1#2##2##3\@nil##4{%
+    \edef##4{\unexpanded{##2}}%
+    \ifx##4\@nnil
+      \edef##4{\unexpanded{##1}}%
+      \expandafter\@secondoftwo
+    \else
+      \expandafter\@firstoftwo
+    \fi
+  }%
+  \SKV@resolve#1#2{\@nil}\@nil#3%
+}
+\SKV@def*\SKV@addtouserval{%
+  \SKV@addtolist+{SKV@\XKV@header uservalue}\SKV@resa}
+\SKV@def*\SKV@gaddtouserval{%
+  \SKV@addtolist+?{SKV@\XKV@header uservalue}\SKV@resa}
+\SKV@def*\SKV@addtosave{\SKV@addtolist+{XKV@\XKV@header save}\SKV@resa}
+\SKV@def*\SKV@gaddtosave{\begingroup
+  \edef\SKV@tempa{\endgroup
+    \SKV@addtolist+?{XKV@\XKV@header save}{\global{\SKV@resa}}}%
+  \SKV@tempa
+}
+\SKV@def*\SKV@findkeypointers#1{%
+  \SKV@resolvekey{#1}\uservalue\savevalue\@nil\SKV@resa
+  {%
+    \SKV@addtouserval\SKV@addtosave
+  }{%
+    \SKV@resolvekey{#1}\guservalue\savevalue\@nil\SKV@resa
+    {%
+      \SKV@gaddtouserval\SKV@addtosave
+    }{%
+      \SKV@resolvekey{#1}\savevalue\uservalue\@nil\SKV@resa
+      {%
+        \SKV@addtouserval\SKV@addtosave
+      }{%
+        \SKV@resolvekey{#1}\gsavevalue\uservalue\@nil\SKV@resa
+        {%
+          \SKV@addtouserval\SKV@gaddtosave
+        }{%
+          \SKV@resolvekey{#1}\guservalue\gsavevalue\@nil\SKV@resa
+          {%
+            \SKV@gaddtouserval\SKV@gaddtosave
+          }{%
+            \SKV@resolvekey{#1}\gsavevalue\guservalue\@nil\SKV@resa
+            {%
+              \SKV@gaddtouserval\SKV@gaddtosave
+            }{%
+              \SKV@resolvekey{#1}\uservalue\@nil\SKV@resa
+              {%
+                \SKV@addtouserval
+              }{%
+                \SKV@resolvekey{#1}\guservalue\@nil\SKV@resa
+                {%
+                  \SKV@gaddtouserval
+                }{%
+                  \SKV@resolvekey{#1}\savevalue\@nil\SKV@resa
+                  {%
+                    \SKV@addtosave
+                  }{%
+                    \SKV@resolvekey{#1}\gsavevalue\@nil\SKV@resa
+                    {%
+                      \SKV@gaddtosave
+                    }{}%
+                  }%
+                }%
+              }%
+            }%
+          }%
+        }%
+      }%
+    }%
+  }%
+}
 \def\XKV@define@key#1{%
-  \SKV@reservedkey@err{#1}%
-  \SKV@suspendedkey@err{#1}%
-  \SKV@ifnextchar[{\XKV@d@fine@k@y{#1}}{\SKV@d@fine@k@y{#1}}%
+  \SKV@findkeypointers{#1}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    \SKV@ifbrack{\noexpand\XKV@d@fine@key{\SKV@resa}}%
+      {\noexpand\SKV@d@fine@key{\SKV@resa}}%
+  }%
+  \SKV@tempa
 }
-\def\XKV@d@fine@k@y#1[#2]#3{%!
+\def\XKV@d@fine@key#1[#2]#3{%
   \XKV@define@default{#1}{#2}%
-  \SKV@namedef{\XKV@header#1}##1{#3}%
+  \@namedef{\XKV@header#1}##1{#3}%
 }
-\def\SKV@d@fine@k@y#1#2{\SKV@namedef{\XKV@header#1}##1{#2}}
+\def\SKV@d@fine@key#1#2{\@namedef{\XKV@header#1}##1{#2}}
 \def\XKV@define@cmdkey#1#2[#3]#4{%
-  \SKV@reservedkey@err{#2}%
-  \SKV@suspendedkey@err{#2}%
-  \ifXKV@st\XKV@define@default{#2}{#3}\fi
-  \edef\SKV@tempa{\noexpand\def\@nameuse{\XKV@header#2}####1}%
-  \edef\SKV@tempb{\noexpand\def\@nameuse{#1#2}\unexpanded{{##1}#4}}%
-  \expandafter\SKV@tempa\expandafter{\SKV@tempb}%
-  \SKV@undef\SKV@tempa\SKV@undef\SKV@tempb
+  \SKV@findkeypointers{#2}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+    \SKV@csundef{#1\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
+  \ifXKV@st
+    \SKV@afterfi
+    \SKV@expnext\XKV@define@default\SKV@resa{#3}%
+  \fi
+  \begingroup
+  \def\SKV@tempa{%
+    \expandafter\def\csname\XKV@header\SKV@resa\endcsname####1}%
+  \@threeexpafter\endgroup\expandafter\SKV@tempa\expandafter%
+    {\expandafter\def\csname#1\SKV@resa\endcsname{##1}#4}%
 }
 \def\XKV@define@choicekey#1{%
-  \SKV@reservedkey@err{#1}%
-  \SKV@suspendedkey@err{#1}%
-  \@testopt{\XKV@d@fine@choicekey{#1}}{}%
+  \SKV@findkeypointers{#1}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
+  \begingroup
+  \edef\SKV@tempa{\endgroup
+    \SKV@testopt{\noexpand\XKV@d@fine@choicekey{\SKV@resa}}{}%
+  }%
+  \SKV@tempa
 }
 \def\XKV@define@boolkey#1#2[#3]{%
-  \SKV@reservedkey@err{#2}%
-  \SKV@suspendedkey@err{#2}%
+  \SKV@findkeypointers{#2}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+    \SKV@csundef{#1\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
   \ifXKV@pl
-    \SKV@afterelsefi\expandafter\XKV@d@f@ne@boolkey
+    \def\SKV@n@xt{\SKV@aftercs\XKV@d@f@ne@boolkey}%
   \else
-    \SKV@afterfi\expandafter\XKV@d@fine@boolkey
+    \def\SKV@n@xt{\SKV@aftercs\XKV@d@fine@boolkey}%
   \fi
-  \csname\XKV@header#2\endcsname{#2}{#1#2}{#3}%
+  \edef\SKV@tempa{{\XKV@header\SKV@resa}{\SKV@resa}{#1\SKV@resa}{#3}}%
+  \expandafter\SKV@n@xt\SKV@tempa
+}
+\def\XKV@d@fine@boolkeys#1#2#3{%
+  \SKV@findkeypointers{#1}%
+  \SKV@ifcsundef{\XKV@header\SKV@resa}{}{%
+    \SKV@vbsmsg{warn}{%
+      Key '\SKV@resa' in family '\XKV@tfam' with\SKV@MB
+      prefix '\SKV@pref' redefined\on@line}
+    \SKV@csundef{\XKV@header\SKV@resa}%
+    \SKV@csundef{#2\SKV@resa}%
+  }%
+  \SKV@expnext\SKV@reservkey@err\SKV@resa
+  \SKV@expnext\SKV@suspkey@err\SKV@resa
+  \edef\SKV@tempa{%
+    \noexpand\XKV@d@f@ne@b@olkey\@nameuse{\XKV@header\SKV@resa}%
+    {\SKV@resa}{#2\SKV@resa}{#3}{{\noexpand\@nameuse{#2\SKV@resa
+    \noexpand\XKV@resa}}}%
+  }%
+  \SKV@tempa
 }
 \SKV@pdef*\reserve@keys{\@testopt\SKV@reserve@keys{KV}}
 \SKV@def*\SKV@reserve@keys[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@res@rve@keys\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@despacelist*\SKV@tempa
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@res@rve@keys\SKV@tempa{#2}{#3}%
   }%
 }
 \SKV@def*\SKV@res@rve@keys#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
+  \SKV@despacelist*\XKV@fams
   \SKV@for@b\XKV@fams\XKV@tfam{%
     \XKV@makehd\XKV@tfam
     \SKV@res@rve@k@ys{#3}%
@@ -1151,170 +2233,121 @@
 }
 \SKV@def*\SKV@res@rve@k@ys#1{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@ifnamedef{\XKV@header\SKV@tempa}{%
+    \SKV@ifcsdef{\XKV@header\SKV@tempa}{%
       \SKV@err{%
         Key '\SKV@tempa' with prefix '\SKV@pref' in family
-        \MessageBreak '\XKV@tfam' is already defined
+          \SKV@MB '\XKV@tfam' is already defined
       }{%
         Key '\SKV@tempa' in family '\XKV@tfam' can't be reserved.
-        \MessageBreak You may wish to remove it before reserving it.
-        \MessageBreak In that case, you can use '\string\remove@keys'.
+        \SKV@MB You may wish to remove it before reserving it.
+        \SKV@MB In that case, you can use '\string\remove@keys'.
       }%
     }{%
-      \SKV@nameedef{\XKV@header\SKV@tempa}{%
+      \SKV@csedef{\XKV@header\SKV@tempa}{%
         \SKV@err{%
-          Key '\SKV@tempa' with prefix '\SKV@pref' in family '\XKV@tfam'
-          \MessageBreak was reserved\on@line
+          Key '\SKV@tempa' with prefix '\SKV@pref' in family
+          '\XKV@tfam'\SKV@MB was reserved\on@line
         }{%
           Unreserve '\SKV@tempa' before use.
         }%
       }%
-      \SKV@namedef{\XKV@header\SKV@tempa @reser}{}%
+      \@namedef{\XKV@header\SKV@tempa @reser}{}%
     }%
   }%
 }
-\let\SKV@no\@empty
-\SKV@pdef\SKV@aftergroup{%
-  \SKV@ifstar{\SKV@aft@rgroup\@firstofone}{\SKV@aft@rgroup\unexpanded}%
-}
-\SKV@def\SKV@aft@rgroup#1#2{%
-  \edef\SKV@no{\the\numexpr\SKV@no+1}%
-  \SKV@namexdef{SKV@aft@rgr@up\SKV@no}{%
-    \SKV@namegundef{SKV@aft@rgr@up\SKV@no}%
-    #1{#2}%
-  }%
-  \SKV@aftercsname\aftergroup{SKV@aft@rgr@up\SKV@no}%
-}
-\SKV@pdef\SKV@afterassignment{%
-  \SKV@ifstar{\SKV@aft@rassignment\@firstofone}%
-    {\SKV@aft@rassignment\unexpanded}%
-}
-\SKV@def\SKV@aft@rassignment#1#2{%
-  \begingroup
-  \edef\SKV@no{\the\numexpr\SKV@no+1}%
-  \SKV@namexdef{SKV@aft@rassignm@nt\SKV@no}{%
-    \SKV@namegundef{SKV@aft@rassignm@nt\SKV@no}%
-    #1{#2}%
-  }%
-  \expandafter\endgroup\expandafter\afterassignment
-    \csname SKV@aft@rassignm@nt\SKV@no\endcsname
-}
-\SKV@def*\SKV@reservedkey@err#1{%
-  \SKV@ifnamedef{\XKV@header#1@reser}{%
-    \let\next\SKV@err
-  }{%
-    \let\next\@gobbletwo
-  }%
-  \next{%
-    Key '#1' with prefix '\SKV@pref'\MessageBreak
-    is reserved in family '\XKV@tfam'
-  }{%
-    Unreserve '#1' before use.
-  }%
+\SKV@def*\SKV@reservkey@err#1{%
+  \SKV@ifcsdef{\XKV@header#1@reser}\SKV@err\@gobbletwo
+  {Key '#1' with prefix '\SKV@pref'\SKV@MB
+    is reserved in family '\XKV@tfam'}{Unreserve '#1' before use.}%
 }
 \SKV@def*\ifkeyreserved{\@testopt\SKV@ifkeyreserved{KV}}
 \SKV@def*\SKV@ifkeyreserved[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \XKV@knftrue
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@ifkey@reserved\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@ifkey@reserved\SKV@tempa{#2}{#3}%
   }%
-  \ifXKV@knf
-    \expandafter\@secondoftwo
-  \else
-    \expandafter\@firstoftwo
-  \fi
+  \@nameuse{@\ifXKV@knf second\else first\fi oftwo}%
 }
 \SKV@def*\SKV@ifkey@reserved#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
-  \KV@@sp@def\XKV@tkey{#3}%
+  \SKV@despacelist*\XKV@fams
+  \SKV@trailead{#3}\XKV@tkey
   \XKV@whilist\XKV@fams\XKV@tfam\ifXKV@knf\fi{%
     \XKV@makehd\XKV@tfam
-    \SKV@ifnamedef{\XKV@header\XKV@tkey @reser}{\XKV@knffalse}{}%
+    \SKV@ifcsdef{\XKV@header\XKV@tkey @reser}{\XKV@knffalse}{}%
   }%
 }
 \SKV@def*\ifkeysuspended{\@testopt\SKV@ifkeysuspended{KV}}
 \SKV@def*\SKV@ifkeysuspended[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \XKV@knftrue
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@ifkey@suspended\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@ifkey@suspended\SKV@tempa{#2}{#3}%
   }%
-  \ifXKV@knf
-    \expandafter\@secondoftwo
-  \else
-    \expandafter\@firstoftwo
-  \fi
+  \@nameuse{@\ifXKV@knf second\else first\fi oftwo}%
 }
 \SKV@def*\SKV@ifkey@suspended#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
-  \KV@@sp@def\XKV@tkey{#3}%
+  \SKV@despacelist*\XKV@fams
+  \SKV@trailead{#3}\XKV@tkey
   \XKV@whilist\XKV@fams\XKV@tfam\ifXKV@knf\fi{%
     \XKV@makehd\XKV@tfam
-    \SKV@ifnamedef{\XKV@header\XKV@tkey @sus}{\XKV@knffalse}{}%
+    \SKV@ifcsdef{\XKV@header\XKV@tkey @susp}{\XKV@knffalse}{}%
   }%
 }
 \SKV@def*\ifkeydefined{\@testopt\SKV@ifkeydefined{KV}}
 \SKV@def*\SKV@ifkeydefined[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \XKV@knftrue
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@ifk@ydefined\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@ifk@ydefined\SKV@tempa{#2}{#3}%
   }%
-  \ifXKV@knf
-    \expandafter\@secondoftwo
-  \else
-    \expandafter\@firstoftwo
-  \fi
+  \@nameuse{@\ifXKV@knf second\else first\fi oftwo}%
 }
 \SKV@def*\SKV@ifk@ydefined#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
-  \KV@@sp@def\XKV@tkey{#3}%
+  \SKV@despacelist*\XKV@fams
+  \SKV@trailead{#3}\XKV@tkey
   \XKV@whilist\XKV@fams\XKV@tfam\ifXKV@knf\fi{%
     \XKV@makehd\XKV@tfam
-    \SKV@ifnamedef{\XKV@header\XKV@tkey}{\XKV@knffalse}{}%
+    \SKV@ifcsdef{\XKV@header\XKV@tkey}{\XKV@knffalse}{}%
   }%
 }
 \SKV@def*\SKV@disabledkey@err{%
   \SKV@err{%
     Key '\SKV@disabledkey' with prefix '\SKV@pref' in family
-    \MessageBreak '\XKV@tfam' was disabled\on@line
+    \SKV@MB '\XKV@tfam' was disabled\on@line
   }{%
-    You can't set or reset '\SKV@disabledkey' at this\MessageBreak
-    late stage. Perhaps you're required to set it \MessageBreak
-    earlier, in the document's preamble.
+    You can't set or reset '\SKV@disabledkey' at this\SKV@MB
+    late stage. Perhaps you're required to set it \SKV@MB
+    earlier, within a package or in the document's preamble.
   }%
 }
-\protected\def\disable@keys{%
+\def\disable@keys{%
   \SKV@ifstar{\@testopt\XKV@disable@keys{KV}}%
     {\@testopt\SKV@disable@keys{KV}}%
 }
 \SKV@def*\SKV@disable@keys[#1]#2#3{%
+  \SKV@locfalse
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@dis@ble@keys\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@despacelist*\SKV@tempa
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@dis@ble@keys\SKV@tempa{#2}{#3}%
   }%
 }
 \SKV@def*\SKV@dis@ble@keys#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
+  \SKV@despacelist*\XKV@fams
   \SKV@for@b\XKV@fams\XKV@tfam{%
     \XKV@makehd\XKV@tfam
     \SKV@dis@ble@k@ys{#3}%
@@ -1322,58 +2355,80 @@
 }
 \SKV@def*\SKV@dis@ble@k@ys#1{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@ifnameundef{\XKV@header\SKV@tempa}{%
-      \SKV@warn{Key '\SKV@tempa' with prefix '\SKV@pref'
-        \MessageBreak is undefined in family '\XKV@tfam':
-        \MessageBreak can't be disabled\on@line}%
+    \SKV@ifcsundef{\XKV@header\SKV@tempa}{%
+      \ifSKV@verbose\SKV@disabledkey@warn\fi
     }{%
       \SKV@dis@ble@k@y@\SKV@tempa
     }%
   }%
 }
+\def\SKV@disabledkey@warn{%
+  \SKV@warn{Key '\SKV@tempa' with prefix '\SKV@pref'
+    \SKV@MB is undefined in family '\XKV@tfam':
+    \SKV@MB can't be \ifSKV@loc localized
+    \else disabled\fi\on@line
+  }%
+}
+\def\SKV@disabledkey@info{%
+  \SKV@info{Key '\SKV@disabledkey' with prefix '\SKV@pref'
+    in family '\XKV@tfam'\SKV@MB was \ifSKV@loc localized
+    \else disabled\fi\on@line
+  }%
+}
 \SKV@def*\SKV@dis@ble@k@y@#1{%
   \edef\SKV@disabledkey{#1}%
-  \SKV@ifnameundef{\XKV@header#1@default}{%
+  \SKV@ifcsundef{\XKV@header#1@default}{%
     \edef#1{\noexpand\XKV@define@key{#1}}%
   }{%
     \edef#1{\noexpand\XKV@define@key{#1}[]}%
   }%
-  \SKV@expandargs{0}#1\SKV@disabledkey@err\SKV@nil
-  \SKV@info{Key '\SKV@disabledkey' with prefix '\SKV@pref' in family '\XKV@tfam'
-    \MessageBreak was disabled\on@line}%
+  \SKV@expargs{0}#1\SKV@disabledkey@err\@nil
+  \ifSKV@verbose\SKV@disabledkey@info\fi
 }
-\SKV@def*\SKV@suspendedkey@err#1{%
-  \SKV@ifnamedef{\XKV@header#1@sus}{%
-    \SKV@err{%
-      Key '#1' was suspended from family '\XKV@tfam'
-    }{%
-      You can use \string\restore@key\space to restore '#1'.
-    }%
-  }{}%
+\SKV@pdef*\localize@keys{%
+  \SKV@onlypackage\SKV@savstate
+  \SKV@t@stopta{\@testopt\SKV@localize@keys{KV}}%
 }
-\SKV@def*\SKV@suspendedkey@e@r{%
-  \SKV@err{%
-    Key '\SKV@suspendedkey' in family '\XKV@tfam' was
-    \MessageBreak suspended\on@line
-  }{%
-    You can use \string\restore@key\space to restore '\SKV@suspendedkey'.
+\SKV@def*\SKV@localize@keys[#1]#2#3{%
+  \SKV@loctrue
+  \ifSKV@st
+    \expandafter\SKV@BeforeDocumentStart
+  \else
+    \expandafter\SKV@AfterPackageEnd
+  \fi
+  {%
+    \XKV@checksanitizeb{#1}\SKV@tempa
+    \SKV@despacelist*\SKV@tempa
+    \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+      \SKV@expnext\SKV@dis@ble@keys\SKV@tempa{#2}{#3}%
+    }%
   }%
+  \SKV@resstate
+}
+\SKV@def*\SKV@suspkey@err#1{%
+  \SKV@ifcsdef{\XKV@header#1@susp}\SKV@err\@gobbletwo
+  {Key '#1' was suspended from family '\XKV@tfam'}%
+  {You can use \string\restore@key\space to restore '#1'.}%
+}
+\SKV@def*\SKV@suspkey@e@r{%
+  \SKV@err{Key '\SKV@suspkey' in family '\XKV@tfam' was\SKV@MB
+    suspended\on@line}{You can use \string\restore@key\space
+    to restore '\SKV@suspkey'.}%
 }
 \SKV@pdef*\suspend@keys{\@testopt\SKV@suspend@keys{KV}}
 \SKV@def*\SKV@suspend@keys[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@s@spend@keys\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@despacelist*\SKV@tempa
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@s@spend@keys\SKV@tempa{#2}{#3}%
   }%
 }
 \SKV@def*\SKV@s@spend@keys#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
+  \SKV@despacelist*\XKV@fams
   \SKV@for@b\XKV@fams\XKV@tfam{%
     \XKV@makehd\XKV@tfam
     \SKV@s@sp@nd@keys{#3}%
@@ -1381,45 +2436,46 @@
 }
 \SKV@def*\SKV@s@sp@nd@keys#1{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@ifnameundef{\XKV@header\SKV@tempa}{%
-      \SKV@warn{Key '\SKV@tempa' with prefix '\SKV@pref'
-        \MessageBreak is undefined in family '\XKV@tfam':
-        \MessageBreak can't be suspended\on@line}%
+    \SKV@ifcsundef{\XKV@header\SKV@tempa}{%
+      \SKV@vbsmsg{warn}{%
+        Key '\SKV@tempa' with prefix '\SKV@pref'
+        \SKV@MB is undefined in family '\XKV@tfam':
+        \SKV@MB can't be suspended\on@line}%
     }{%
       \SKV@s@sp@nd@k@ys\SKV@tempa
     }%
   }%
 }
 \SKV@def*\SKV@s@sp@nd@k@ys#1{%
-  \SKV@ifnamedef{\XKV@header#1@sus}{%
+  \SKV@ifcsdef{\XKV@header#1@susp}{%
     \SKV@err{%
-      Key '#1' with prefix '\SKV@pref' was suspended from family '\XKV@tfam'
+      Key '#1' with prefix '\SKV@pref'
+        was suspended from family '\XKV@tfam'
     }{%
       You can use \string\restore@key\space to restore '#1'.
     }%
   }{%
-    \edef\SKV@suspendedkey{#1}%
-    \global\nameletname{\XKV@header#1@sus}{\XKV@header#1}%
-    \SKV@nameedef{\XKV@header#1}{\SKV@suspendedkey@e@r}%
-    \SKV@info{Key '\SKV@suspendedkey' with prefix '\SKV@pref' in
-      \MessageBreak family '\XKV@tfam' was suspended\on@line}%
+    \edef\SKV@suspkey{#1}%
+    \global\SKV@csletcs{\XKV@header#1@susp}{\XKV@header#1}%
+    \SKV@csedef{\XKV@header#1}{\SKV@suspkey@e@r}%
+    \SKV@vbsmsg{info}{Key '\SKV@suspkey' with prefix '\SKV@pref' in
+      \SKV@MB family '\XKV@tfam' was suspended\on@line}%
   }%
 }
 \SKV@pdef*\restore@keys{\@testopt\SKV@restore@keys{KV}}
 \SKV@def*\SKV@restore@keys[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@r@store@keys\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@despacelist*\SKV@tempa
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@r@store@keys\SKV@tempa{#2}{#3}%
   }%
 }
 \SKV@def*\SKV@r@store@keys#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
+  \SKV@despacelist*\XKV@fams
   \SKV@for@b\XKV@fams\XKV@tfam{%
     \XKV@makehd\XKV@tfam
     \SKV@r@st@re@keys{#3}%
@@ -1427,42 +2483,42 @@
 }
 \SKV@def*\SKV@r@st@re@keys#1{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@ifnameundef{\XKV@header\SKV@tempa}{%
-      \SKV@warn{Key '\SKV@tempa' with prefix '\SKV@pref'
-        \MessageBreak is undefined in family '\XKV@tfam':
-        \MessageBreak can't be restored\on@line}%
+    \SKV@ifcsundef{\XKV@header\SKV@tempa}{%
+      \SKV@vbsmsg{warn}{Key '\SKV@tempa' with prefix '\SKV@pref'
+        \SKV@MB is undefined in family '\XKV@tfam':
+        \SKV@MB can't be restored\on@line}%
     }{%
       \SKV@r@st@re@k@ys\SKV@tempa
     }%
   }%
 }
 \SKV@def*\SKV@r@st@re@k@ys#1{%
-  \SKV@ifnameundef{\XKV@header#1@sus}{%
+  \SKV@ifcsundef{\XKV@header#1@susp}{%
     \SKV@err{Key '#1' wasn't suspended from family
-      \MessageBreak '\XKV@tfam': can't be restored\on@line}\@ehc
+      \SKV@MB '\XKV@tfam': can't be restored\on@line}%
+      {I can't restore unsuspended key '#1'}%
   }{%
     \edef\SKV@restoredkey{#1}%
-    \nameletname{\XKV@header#1}{\XKV@header#1@sus}%
-    \SKV@nameundef{\XKV@header#1@sus}%
-    \SKV@info{Key '\SKV@restoredkey' with prefix '\SKV@pref' in family
-      \MessageBreak '\XKV@tfam' restored\on@line}%
+    \SKV@csletcs{\XKV@header#1}{\XKV@header#1@susp}%
+    \SKV@csundef{\XKV@header#1@susp}%
+    \SKV@vbsmsg{info}{Key '\SKV@restoredkey' with prefix
+      '\SKV@pref' in family \SKV@MB '\XKV@tfam' restored\on@line}%
   }%
 }
 \SKV@pdef*\remove@keys{\@testopt\SKV@remove@keys{KV}}
 \SKV@def*\SKV@remove@keys[#1]#2#3{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
-  \SKV@CommandGenParser{,}%
-  \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \expandafter\SKV@r@move@keys\expandafter{\SKV@tempa}{#2}{#3}%
+  \SKV@despacelist*\SKV@tempa
+  \SKV@for*[,]\SKV@tempa\SKV@tempa{%
+    \SKV@expnext\SKV@r@move@keys\SKV@tempa{#2}{#3}%
   }%
 }
 \SKV@def*\SKV@r@move@keys#1#2#3{%
   \XKV@makepf{#1}%
   \XKV@checksanitizeb{#2}\XKV@fams
-  \SKV@expandargs{1}\XKV@sp@deflist\XKV@fams\XKV@fams\SKV@nil
+  \SKV@despacelist*\XKV@fams
   \SKV@for@b\XKV@fams\XKV@tfam{%
     \XKV@makehd\XKV@tfam
     \SKV@r@m@ve@keys{#3}%
@@ -1470,12 +2526,20 @@
 }
 \SKV@def*\SKV@r@m@ve@keys#1{%
   \XKV@checksanitizeb{#1}\SKV@tempa
-  \SKV@expandargs{1}\XKV@sp@deflist\SKV@tempa\SKV@tempa\SKV@nil
+  \SKV@despacelist*\SKV@tempa
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@ifnameundef{\XKV@header\SKV@tempa}{%
-      \SKV@warn{Key '\SKV@tempa' with prefix '\SKV@pref'
-        \MessageBreak is undefined in family '\XKV@tfam':
-        \MessageBreak I can't remove or unreserve it\on@line}%
+    \SKV@ifcsundef{\XKV@header\SKV@tempa @susp}{}{%
+      \SKV@err{Key '\SKV@tempa' with prefix '\SKV@pref'
+        \SKV@MB was suspended from family '\XKV@tfam':
+        \SKV@MB I can't remove/unreserve it\on@line.
+        \SKV@MB You need to first restore key '\SKV@tempa'
+        \SKV@MB before you can remove/unreserve it}%
+        {First restore key '\SKV@tempa' before removing it.}%
+    }%
+    \SKV@ifcsundef{\XKV@header\SKV@tempa}{%
+      \SKV@vbsmsg{warn}{Key '\SKV@tempa' with prefix '\SKV@pref'
+        \SKV@MB is undefined in family '\XKV@tfam':
+        \SKV@MB I can't remove or unreserve it\on@line}%
     }{%
       \SKV@r@m@ve@k@ys\SKV@tempa
     }%
@@ -1484,28 +2548,39 @@
 \SKV@def*\SKV@r@m@ve@k@ys#1{%
   \begingroup
   \edef\SKV@tempa{\XKV@header#1,\XKV@header#1@default,
-    \XKV@header#1@func,%\XKV@header#1@value,
-    \XKV@header#1@altlist,\XKV@header#1@reser
+    \XKV@header#1@func,\XKV@header#1@altlist,
+    \XKV@header#1@reser
   }%
   \SKV@for@b\SKV@tempa\SKV@tempa{%
-    \SKV@expandargs{1}\KV@@sp@def\SKV@tempa\SKV@tempa\SKV@nil
-    \SKV@namegundef{\SKV@tempa}%
+    \SKV@despace\SKV@tempa
+    \SKV@csgundef{\SKV@tempa}%
   }%
   \endgroup
-  \SKV@info{Key '#1' with prefix '\SKV@pref' in family '\XKV@tfam'
-    \MessageBreak was removed\on@line}%
+  \SKV@vbsmsg{info}{Key '#1' with prefix '\SKV@pref' in family\SKV@MB
+    '\XKV@tfam' was removed\on@line}%
 }
 \SKV@newlet\unreserve@keys\remove@keys
+\SKV@def*\uservaluekeys{\XKV@testoptb\SKV@uservaluekeys}
+\SKV@def*\SKV@uservaluekeys#1{%
+  \SKV@ifcsundef{SKV@\XKV@header uservalue}{%
+    \XKV@checksanitizeb{#1}\SKV@tempa
+    \SKV@csxdef{SKV@\XKV@header uservalue}{\SKV@expox{\SKV@tempa}}%
+  }{%
+    \SKV@aftercs\XKV@merge{SKV@\XKV@header uservalue}{#1}\XKV@getsg
+  }%
+}
 \def\setkeys{%
-  \def\fif##1{%
-    \SKV@findescape{##1}{%
-      \SKV@err{Bad argument '\string##1'}%
-        {Backslash in '\string##1' not allowed.}%
-    }{}%
+  \def\skif##1{%
+    \SKV@ensurenoscape{##1}%
+    \SKV@ifcsdef{if##1}{}{%
+      \SKV@err{Undefined boolean '##1'}%
+        {Boolean '##1' undefined: This is an '\string\skif' error.}%
+    }%
     \csname if##1\endcsname
   }%
-  \let\ffi\fi
-  \XKV@testopta{\XKV@testoptc\XKV@setkeys}%
+  \let\skifx\ifx\let\skifcase\ifcase\let\skor\or
+  \let\skelse\else\let\skfi\fi
+  \SKV@sktrue\XKV@testopta{\XKV@testoptc\XKV@setkeys}%
 }
 \def\XKV@setkeys[#1]#2{%
   \XKV@checksanitizea{#2}\XKV@resb
@@ -1517,163 +2592,247 @@
   }%
   \ifnum\XKV@depth=\z@\let\XKV@rm\@empty\fi
   \XKV@usepresetkeys{#1}{preseth}%
-  \expandafter\XKV@s@tkeys\expandafter{\XKV@resb}{#1}%
+  \SKV@expnext\XKV@s@tkeys\XKV@resb{#1}%
   \XKV@usepresetkeys{#1}{presett}%
   \let\CurrentOption\@empty
+  \SKV@skfalse
+}
+\def\XKV@s@tk@ys@#1{%
+  \SKV@ifcsundef{\XKV@header\XKV@tkey}{%
+    \SKV@vbsmsg{warn}{No key macro for key '\XKV@tkey'}%
+  }{%
+    \XKV@knffalse
+    \SKV@ifcsundef{SKV@\XKV@header uservalue}{}{%
+      \SKV@aftercs\SKV@testuservaluekey
+        {SKV@\XKV@header uservalue}\XKV@tkey
+      \ifSKV@uv
+        \SKV@ifnotblank{#1}{}{%
+          \SKV@err{You're required to supply a value\SKV@MB
+            for key '\XKV@tkey'}%
+            {Supply a value for key '\XKV@tkey' before continuing.}%
+        }%
+      \fi
+    }%
+    \SKV@ifcsundef{XKV@\XKV@header save}{}{%
+      \SKV@aftercs\XKV@testsavekey{XKV@\XKV@header save}\XKV@tkey
+    }%
+    \ifXKV@rkv
+      \ifXKV@sg\expandafter\global\fi
+      \SKV@aftercs\let{XKV@\XKV@header\XKV@tkey @value}\XKV@tempa
+    \fi
+    \SKV@expnext\XKV@replacepointers\XKV@tempa
+    \SKV@ifblank{#1}{%
+      \SKV@ifcsundef{\XKV@header\XKV@tkey @default}{%
+        \SKV@err{'\XKV@tkey' in family '\XKV@tfam' with\SKV@MB
+          prefix '\XKV@pref' has no default value and\SKV@MB
+          you haven't supplied a value for it either}%
+          {Supply a value for key '\XKV@tkey' and rerun.}%
+      }{%
+        \SKV@xaftercs\XKV@default{\XKV@header\XKV@tkey @default}\@nil
+      }%
+    }{%
+      \XKV@savstate
+      \csname\XKV@header\XKV@tkey\expandafter
+        \endcsname\expandafter{\XKV@tempa}\relax
+      \XKV@resstate
+    }%
+  }%
+}
+\SKV@def*\SKV@testuservaluekey#1#2{%
+  \let\SKV@st@aux\ifSKV@st\SKV@sttrue\SKV@uvfalse
+  \XKV@whilist#1\SKV@tempa\ifSKV@st\fi{%
+    \ifx#2\SKV@tempa\SKV@uvtrue\SKV@stfalse\fi
+  }%
+  \let\ifSKV@st\SKV@st@aux\SKV@relax\SKV@st@aux
 }
 \SKV@def*\SKV@remspaceletter#1#2{%
   \begingroup
-  \XKV@toks\expandafter{#2 #1}%
-  \def\SKV@tempa##1 #1##2\SKV@nil{%
+  \SKV@toks\expandafter{#2 #1}%
+  \def\SKV@tempa##1 #1##2\@nil{%
     \SKV@ifblank{##2}{%
-      \XKV@toks{##1}%
+      \SKV@toks{##1}%
     }{%
-      \XKV@toks{##1#1##2}%
-      \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
+      \SKV@toks{##1#1##2}%
+      \expandafter\SKV@tempa\the\SKV@toks\@nil
     }%
   }%
-  \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
-  \xdef#2{\the\XKV@toks}%
+  \expandafter\SKV@tempa\the\SKV@toks\@nil
+  \xdef#2{\the\SKV@toks}%
   \endgroup
 }
 \SKV@def*\SKV@remletterspace#1#2{%
   \begingroup
-  \XKV@toks\expandafter{#2#1 }%
-  \def\SKV@tempa##1#1 ##2\SKV@nil{%
+  \SKV@toks\expandafter{#2#1 }%
+  \def\SKV@tempa##1#1 ##2\@nil{%
     \SKV@ifblank{##2}{%
-      \XKV@toks{##1}%
+      \SKV@toks{##1}%
     }{%
-      \XKV@toks{##1#1##2}%
-      \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
+      \SKV@toks{##1#1##2}%
+      \expandafter\SKV@tempa\the\SKV@toks\@nil
     }%
   }%
-  \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
-  \xdef#2{\the\XKV@toks}%
+  \expandafter\SKV@tempa\the\SKV@toks\@nil
+  \xdef#2{\the\SKV@toks}%
   \endgroup
 }
 \SKV@def*\SKV@remletterletter#1#2{%
   \begingroup
-  \XKV@toks\expandafter{#2#1#1}%
-  \def\SKV@tempa##1#1#1##2\SKV@nil{%
-    \XKV@toks{##1#1##2}%
-    \SKV@ifblank{##2}{}{\expandafter\SKV@tempa\the\XKV@toks\SKV@nil}%
-  }%
-  \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
-  \def\SKV@tempa##1#1#1\SKV@nil{\gdef#2{##1}}%
-  \expandafter\SKV@tempa\the\XKV@toks#1\SKV@nil
+  \SKV@toks\expandafter{#2#1#1}%
+  \def\SKV@tempa##1#1#1##2\@nil{%
+    \SKV@toks{##1#1##2}%
+    \SKV@ifblank{##2}{}{%
+      \expandafter\SKV@tempa\the\SKV@toks\@nil}%
+  }%
+  \expandafter\SKV@tempa\the\SKV@toks\@nil
+  \def\SKV@tempa##1#1#1\@nil{\gdef#2{##1}}%
+  \expandafter\SKV@tempa\the\SKV@toks#1\@nil
   \endgroup
 }
-\def\SKV@remcommaequal#1#2{%
+\SKV@def*\SKV@remcommaequal#1#2{%
   \begingroup
-  \XKV@toks\expandafter{#2#1}%
-  \def\SKV@tempa##1#1##2\SKV@nil{%
+  \SKV@toks\expandafter{#2#1}%
+  \def\SKV@tempa##1#1##2\@nil{%
     \SKV@ifblank{##2}{%
-      \XKV@toks{##1}%
+      \SKV@toks{##1}%
     }{%
-      \XKV@toks{##1=##2}%
-      \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
+      \SKV@toks{##1=##2}%
+      \expandafter\SKV@tempa\the\SKV@toks\@nil
     }%
   }%
-  \expandafter\SKV@tempa\the\XKV@toks\SKV@nil
-  \xdef#2{\the\XKV@toks}%
+  \expandafter\SKV@tempa\the\SKV@toks\@nil
+  \xdef#2{\the\SKV@toks}%
   \endgroup
 }
 \SKV@def*\SKV@normalizea#1{%
-  \@expandtwoargs\in@{ ,}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{ ,}{\SKV@expox{#1}}%
   \ifin@\SKV@remspaceletter{,}#1\fi
-  \@expandtwoargs\in@{, }{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{, }{\SKV@expox{#1}}%
   \ifin@\SKV@remletterspace{,}#1\fi
-  \@expandtwoargs\in@{,,}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{,,}{\SKV@expox{#1}}%
   \ifin@\SKV@remletterletter{,}#1\fi
-  \@expandtwoargs\in@{ =}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{ =}{\SKV@expox{#1}}%
   \ifin@\SKV@remspaceletter{=}#1\fi
-  \@expandtwoargs\in@{= }{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{= }{\SKV@expox{#1}}%
   \ifin@\SKV@remletterspace{=}#1\fi
-  \@expandtwoargs\in@{==}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{==}{\SKV@expox{#1}}%
   \ifin@\SKV@remletterletter{=}#1\fi
-  \@expandtwoargs\in@{,=}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{,=}{\SKV@expox{#1}}%
   \ifin@\SKV@remcommaequal{,=}#1\fi
-  \@expandtwoargs\in@{=,}{\SKV@expandox{#1}}%
+  \@expandtwoargs\SKV@in@{=,}{\SKV@expox{#1}}%
   \ifin@\SKV@remcommaequal{=,}#1\fi
 }
-\SKV@pdef\AtStartOfDocument{\AtBeginDocument}
-\SKV@pdef\BeforeStartOfDocument{\SKV@gapptomacro@a\SKV@beforestartdocument}
-\SKV@def*\SKV@beforestartdocument{}
-\SKV@preptomacro@a\document{%
-  \endgroup
-  \let\BeforeStartOfDocument\@firstofone
-  \SKV@beforestartdocument
-  \protected\long\def\BeforeStartOfDocument{\expandafter\@notprerr\@gobble}%
-  \SKV@undef\SKV@beforestartdocument
-  \begingroup
-}
-\SKV@pdef\AfterStartOfDocument{\SKV@gapptomacro@a\SKV@afterstartdocument}
-\SKV@def*\SKV@afterstartdocument{}
-\SKV@apptomacro@a\document{%
-  \let\AfterStartOfDocument\@firstofone
-  \SKV@afterstartdocument
-  \protected\long\def\AfterStartOfDocument{\expandafter\@notprerr\@gobble}%
-  \SKV@undef\SKV@afterstartdocument\ignorespaces
-}
 \SKV@def*\SKV@gobblescape{%
   \ifnum\escapechar>255\else
   \ifnum\escapechar<0\else
-    \expandafter\expandafter\csname @gobble\ifnum\escapechar=32 space\fi
-    \expandafter\expandafter\expandafter\endcsname
+    \expandafter\expandafter
+    \csname @gobble\ifnum\escapechar=32 space\fi
+    \@threeexpafter\endcsname
   \fi\fi
-  \string
+  \string%
 }
 \SKV@def*\SKV@save#1{%
-  \SKV@findescape{#1}{}{\SKV@err{'#1' not a control sequence}\@ehc}
-  \SKV@ifnamedef{Saved\SKV@gobblescape#1}{%
+  \SKV@ensurescape{#1}%
+  \edef\SKV@tempa{saved\SKV@gobblescape#1}%
+  \SKV@ifcsdef\SKV@tempa{%
     \SKV@err{%
-      \string#1\space already saved. You've to restore\MessageBreak
-      it or undefine \SKV@noexpandcs{Saved\SKV@gobblescape#1}%
-      before\MessageBreak you can save \string#1\space again
+      \string#1\space already saved. You've to restore\SKV@MB
+      it or undefine '\SKV@expcsox{\SKV@tempa}' before\SKV@MB
+      you can save \string#1\space again
     }\@ehc
   }{%
-    \nameletcs{Saved\SKV@gobblescape#1}{#1}%
+    \SKV@ifdef{#1}{%
+      \SKV@cslet\SKV@tempa{#1}%
+    }{%
+      \SKV@err{Undefined '\string#1' can't be saved\on@line}%
+        {You can't restore undefined commands.\SKV@MB
+        So why save undefined '\string#1' here?}%
+    }%
   }%
 }
 \SKV@def*\SKV@restore#1{%
-  \SKV@findescape{#1}{}{\SKV@err{'#1' not a control sequence}\@ehc}
-  \SKV@ifnamedef{Saved\SKV@gobblescape#1}{%
-    \csletname{#1}{Saved\SKV@gobblescape#1}%
-    \SKV@nameundef{Saved\SKV@gobblescape#1}%
+  \SKV@ensurescape{#1}%
+  \edef\SKV@tempa{saved\SKV@gobblescape#1}%
+  \SKV@ifcsdef\SKV@tempa{%
+    \def\SKV@n@xt{\SKV@letcs#1\SKV@tempa\SKV@csundef\SKV@tempa}%
   }{%
-    \SKV@warn{%
-      \@nameuse{Saved\SKV@gobblescape#1} undefined: can't be restored\on@line.
-      \MessageBreak Note that each call of \string\SKV@restore\space undefines
-      \MessageBreak the saved command
+    \SKV@err{%
+      '\@nameuse\SKV@tempa' is undefined:\SKV@MB
+      '\string#1' can't be restored\on@line
+    }{%
+      '\string#1' can't be restored\on@line.\SKV@MB
+      Note that each call to \string\SKV@restore\space
+      undefines\SKV@MB the saved command.
     }%
   }%
+  \SKV@n@xt
 }
-\providecommand*\input@path{}
+\SKV@providedef*\input@path{}
 \SKV@pdef*\InputFileOnce{%
-  \edef\SKV@no{\z@}\SKV@save\input@path
-  \SKV@testopt\SKV@InputFileOnce{.}%
+  \def\SKV@inputfile##1##2{%
+    \InputIfFileExists{##2}{%
+      \SKV@aftercs\let{##2@read}\@empty
+      \let\SKV@inp@tfile\relax
+    }{%
+      \typein[\Answer]{^^J! File '\string##2' does not exist.^^J
+      Enter filename or 'no' and <return> to continue.}%
+      \SKV@oifstrequal{\Answer}{no}{%
+        \let\SKV@inp@tfile\relax
+      }{%
+        \def\SKV@inp@tfile{%
+          \SKV@expargs{0}{\SKV@InputFileOnce[##1]}\Answer\@nil
+        }%
+      }%
+    }%
+  }%
+  \let\SKV@no\z@
+  \SKV@save\input@path
+  \SKV@t@stopta{\SKV@testopt\SKV@InputFileOnce{.}}%
 }
 \SKV@def*\SKV@InputFileOnce[#1]#2{%
-  \SKV@gapptomacro@a\input@path{{#1/}}%
-  \if X\SKV@nameuse{#2@read}\relax
-    \ifSKV@inputonce
-      \SKV@afterelsefi
-      \SKV@err{! File '#2' already read}{File '#2' can't be read again.}%
-    \fi
+  \gapptomac\input@path{{#1/}}%
+  \ifSKV@st
+    \SKV@afterelsefi
+    \SKV@inputfile{#1}{#2}%
   \else
-    \SKV@namegdef{#2@read}{X}%
-    \InputIfFileExists{#2}{}{%
-      \typein[\Answer]{^^J! File '\string#2' does not exist.^^J
-      Enter filename or 'n' and <return> to continue.}%
-      \if n\Answer\relax\else
-        \SKV@expandargs{0}{\SKV@InputFileOnce[#1]}\Answer\SKV@nil
-      \fi
+    \SKV@afterfi
+    \SKV@ifcsdef{#2@read}{%
+      \SKV@vbsmsg{warn}{File '#2' already read:\SKV@MB
+        File '#2' can't be read again}%
+    }{%
+      \SKV@inputfile{#1}{#2}%
     }%
   \fi
+  \SKV@inp@tfile
   \ifnum\SKV@no=\z@\SKV@restore\input@path\fi
-  \edef\SKV@no{\@ne}%
+  \let\SKV@no\@ne
+}
+\SKV@pdef\SKV@notloaded@err#1{%
+  \SKV@ifcsdef{ver@#1.\@pkgextension}{}{%
+    \SKV@err{Package '#1' wasn't loaded}%
+      {Document has started and package '#1' wasn't loaded.}%
+  }%
+}
+\SKV@def*\SKV@notloaded{}
+\SKV@pdef*\@ensurepackageloaded#1{%
+  \SKV@for[,]{#1}\SKV@resvd{%
+    \expandafter\gapptomac\expandafter\SKV@notloaded
+      \expandafter{\expandafter\SKV@do@b\expandafter{\SKV@resvd}}%
+  }%
+}
+\SKV@AtDocumentStart{%
+  \let\SKV@do@b\SKV@notloaded@err
+  \SKV@notloaded
+  \global\let\SKV@do@b\@gobble
+}
+\SKV@onlypreamble{%
+  \SKV@preamblecmds\SKV@onlypreamble
+  \@afterpackageloaded\@ifpackagecurrent\@ifpackagenotcurrent
+  \SKV@notloaded\@ensurepackageloaded\SKV@AtPackageEnd
+  \SKV@AtClassEnd\SKV@BeforePackageEnd\SKV@BeforeClassEnd
+  \SKV@AfterPackageEnd\SKV@AfterClassEnd\SKV@BeforeLastPage
+  \SKV@AfterLastPage\SKV@AfterDocumentEnd
 }
 
 \endinput
 
-%%% End of file skeyval.sty %%%
\ No newline at end of file
+%%% End of file skeyval.sty %%%