path: root/Master/texmf-dist/tex/context/third/letter/interface/default.nli

%D \module
%D   [       file=default,
%D        version=2008.10.27,
%D          title=\CONTEXT\ Letter Interface,
%D       subtitle=Default Interface,
%D         author=Wolfgang Schuster,
%D           date=\currentdate,
%D      copyright=Wolfgang Schuster,
%D          email=schuster.wolfgang@googlemail.com,
%D        license=Public Domain]

%M \loadsetups[letter.xml]

%D \subject{Constants and Variables}

\unprotect

%D I define a few additional constants and variables, I will move them
%D to the base some time.

\startinterface all
  \setinterfaceconstant {opening}      {opening}
  \setinterfaceconstant {content}      {content}
  \setinterfaceconstant {closing}      {closing}
  \setinterfaceconstant {signature}    {signature}
  \setinterfaceconstant {dispatch}     {dispatch}
  \setinterfaceconstant {appendices}   {appendices}
  \setinterfaceconstant {fromaddress}  {fromaddress}
  \setinterfaceconstant {frombank}     {frombank}
  \setinterfaceconstant {frommail}     {frommail}
  \setinterfaceconstant {fromfax}      {fromfax}
  \setinterfaceconstant {fromlogo}     {fromlogo}
  \setinterfaceconstant {fromname}     {fromname}
  \setinterfaceconstant {fromphone}    {fromphone}
  \setinterfaceconstant {fromurl}      {fromurl}
  \setinterfaceconstant {toname}       {toname}
  \setinterfaceconstant {toaddress}    {toaddress}
  \setinterfaceconstant {enclosure}    {enclosure}
  \setinterfaceconstant {copy}         {copy}
  \setinterfaceconstant {postscript}   {postscript}
  \setinterfaceconstant {attention}    {attention}
  \setinterfaceconstant {distribution} {distribution}
  \setinterfaceconstant {salutation}   {salutation}
  \setinterfaceconstant {addressee}    {addressee}
\stopinterface

\startinterface all
  \setinterfacevariable {e}          {e}
  \setinterfacevariable {data}       {data}
  \setinterfacevariable {sender}     {sender}
  \setinterfacevariable {dispatch}   {dispatch}
  \setinterfacevariable {enclosure}  {enclosure}
  \setinterfacevariable {copy}       {copy}
  \setinterfacevariable {nobreak}    {nobreak}
  \setinterfacevariable {endgraf}    {endgraf}
  \setinterfacevariable {memo}       {memo}
  \setinterfacevariable {addressee}  {addressee}
  \setinterfacevariable {french}     {french}
  \setinterfacevariable {simplified} {simplified}
  \setinterfacevariable {fullblock}  {fullblock}
  \setinterfacevariable {hanging}    {hanging}
  \setinterfacevariable {modified}   {modified}
\stopinterface

%D \subject{Reference line}
%D 
%D Dimen value to save the height of the reference line.

\newdimen\letter!height!reference

%D We come now to the new macros defined in this file, they are meant to place the
%D information about date, phone number and more information. You could select on of
%D the alternatives with \type{\setupletter[alternative=...]}.
%D 
%D I define here only what I need myself but you're free to define your own
%D alternatives but try to avoid to use the same names as I do. You could also send
%D me your alternatives and I will include them.
%D 
%D This is the first alternative a, it use the values from the style file without any
%D change, this is the normal layout for a DIN letter.

\long\def\doformatreferencelista#1%
  {\def\\{\egroup\hbox\bgroup}%
   \setupinterlinespace\hbox\bgroup#1\egroup\par}

\long\def\formatreferencelista#1%
  {\bgroup
   \convertargument#1\to\ascii
   \vbox
     {\vbox{\doattributes{\????ld\ascii}\c!titlestyle\c!titlecolor
        {\doformatreferencelista{\labeltext{\v!letter:\ascii}}}}
      \vtop{\doattributes{\????ld\ascii}\c!textstyle\c!textcolor
        {\doformatreferencelista{\lettervalue\ascii}}}}%
   \egroup
   \hfill}

\setvalue{\v!letter:\v!reference:\v!a}%
  {\setbox\scratchbox\hbox\!!to\hsize
     {\getcommacommandsize[\@@@@ldlist]% \@@@@ldreference?
      \ifnum\commalistsize<\plustwo\hfill\fi
      \processcommacommand[\@@@@ldlist]\formatreferencelista\unskip}%
   \global\letter!height!reference\dimexpr\ht\scratchbox+\dp\scratchbox\relax
   \box\scratchbox}

\startsetups[letter:reference:\v!a]

\setupletterstyle
  [\v!reference]
  [\c!hoffset=\backspace,
   \c!voffset=\dimexpr\letterstylevalue\v!address\c!voffset+\letterstylevalue\v!address\c!height+\plusthree\c!mm\relax,
   \c!width=\textwidth]

\setupletterstyle
  [\v!firstpage]
  [\c!topspace=\dimexpr\letterstylevalue\v!reference\c!voffset+\letter!height!reference+\plustwo\lineheight\relax]

\stopsetups

%D This is the alternative b, you could use it if you want to place the information
%D in a infoblock not just a simple line, it is also better suited if you want to
%D place more infomration.

\long\def\formatreferencelistb#1%
  {\bgroup
   \doifelse{#1}\v!line
     {\blank[\v!line]}
     {\hbox
        {\doattributes{\????ld#1}\c!titlestyle\c!titlecolor
           {\labeltext{\v!letter:#1}\lettervalue{#1\c!separator}}%
         \doattributes{\????ld#1}\c!textstyle\c!textcolor
           {\lettervalue{#1}}}}%
   \egroup}

\setvalue{\v!letter:\v!reference:\v!b}%
  {\vtop % why not \vbox?
     {\processcommacommand[\@@@@ldlist]\formatreferencelistb}}

\startsetups[letter:reference:\v!b]

\setupletterstyle
  [\v!reference]
  [\v!layer]
  [\c!hoffset=125.7mm,
   \c!voffset=\letterstylevalue\v!address\c!voffset]

\setupletterstyle
  [\v!reference]
  [\v!frame]
  [\c!width=\dimexpr\paperwidth-\letterstylevalue{\v!reference\v!layer}\c!hoffset-\cutspace\relax,
   \c!height=\v!fit]

\stopsetups

%D The third alternative c could used, if you want to place just a single line
%D with text and nothing more, like your place and the date. You need only the
%D following two lines in your document.
%D 
%D \starttyping
%D \setupletter[alternative=c,list=reference]
%D \setupletter[reference=\rightaligned{Place, \currentdate}]
%D \stoptyping

\long\def\formatreferencelistc#1%
  {\bgroup
   \convertargument#1\to\ascii
   \doattributes{\????ld\ascii}\c!textstyle\c!textcolor
     {\lettervalue\ascii}%
   \egroup}

\setvalue{\v!letter:\v!reference:\v!c}%
  {\hbox\!!to\hsize
     {\processcommacommand[\@@@@ldlist]\formatreferencelistc}}

\startsetups[letter:reference:\v!c]

\setups[letter:reference:\v!a]

\stopsetups

%D Alternative d, text is placed in a block like alternative bit the text
%D is put in a table.

\long\def\doformatreferencelistd#1%
  {\doifelse{#1}\v!line
     {\NC\NC\NC\NR} % ugly but working
     {\NC \doattributes{\????ld#1}\c!titlestyle\c!titlecolor
            {\labeltext{\v!letter:#1}\lettervalue{#1\c!separator}}%
      \NC\doattributes{\????ld#1}\c!textstyle\c!textcolor{\lettervalue{#1}}
      \NC\NR}}

\def\formatreferencelistd#1%
  {\appendtoks\doformatreferencelistd{#1}\to\scratchtoks}

\setvalue{\v!letter:\v!reference:\v!d}%
  {\vtop % why not \vbox?
     {\scratchtoks\emptytoks
      \processcommacommand[\@@@@ldlist]\formatreferencelistd
      \setuptabulate[\c!before=,\c!after=]%
      \starttabulate[|l|l|]
      \the\scratchtoks
      \stoptabulate}}

\startsetups[letter:reference:\v!d]

\setupletterstyle
  [\v!reference]
  [\v!layer]
  [\c!hoffset=125.7mm,
   \c!voffset=\letterstylevalue\v!address\c!voffset]

\setupletterstyle
  [\v!reference]
  [\v!frame]
  [\c!width=\dimexpr\paperwidth-\letterstylevalue{\v!reference\v!layer}\c!hoffset-\cutspace\relax,
   \c!height=\v!fit]

\stopsetups

%D Alternative e, nearly the same as a but you could control the width of the
%D fields with the width key for \tex{setupletter}.

\long\def\doformatreferenceliste#1%
  {\def\\{\egroup\hbox\bgroup}%
   \setupinterlinespace\hbox\bgroup#1\egroup\par}

\long\def\formatreferenceliste#1%
  {\bgroup
   \convertargument#1\to\ascii
   \doifelselettervalue{\ascii\c!width}
     {\hbox\!!to\lettervalue{\ascii\c!width}}
     {\hbox}%
     {\vbox
        {\vbox{\doattributes{\????ld\ascii}\c!titlestyle\c!titlecolor
           {\doformatreferenceliste{\labeltext{\v!letter:\ascii}}}}
         \vtop{\doattributes{\????ld\ascii}\c!textstyle\c!textcolor
           {\doformatreferenceliste{\lettervalue\ascii}}}}}%
   \egroup}

\setvalue{\v!letter:\v!reference:\v!e}%
  {\hbox\!!to\hsize
     {\processcommacommand[\@@@@ldlist]\formatreferenceliste\hss}}

\startsetups[letter:reference:\v!e]

\setups[letter:reference:\v!a]

\stopsetups

%D The alternative \mono{none} could be used to disable the reference.
%D 
%D The advantage is to change only the list alternative to nothing, another
%D method to get this result to use alternative c and remove all values from
%D the reference but the none key is better.

\resetvalue{\v!letter:\v!reference:\v!none}

\startsetups[letter:reference:\v!none]

  % Use the topspace value from the style

\stopsetups

%D \subject{Setup commands}
%D 
%D \macros
%D   {setupletter,setlettervalue}
%D 
%D The values for the letter field is set eitheir either with \tex{setupletter}
%D or with \tex{setlettervalue}, the first commands allows you to input the data
%D in a key-val list while the second is only able to accept a single value.
%D 
%D The first definition for \tex{setupletter} was defined in \filename{t-letter.tex}
%D and used till \date[d=20,m=4,y=2008] but I decided to replace it by a simpler
%D method to avoid a few lines of code in my letter and the letter versions from
%D \date[d=21,m=4,y=2008] will use the new user interface. The old definition from
%D \filename{t-letter.tex} is now oveloaded in will eventually disappear.
%D 
%D The second command to set \tex{setlettervalue} was developed as a alternative
%D method to set values for the letter, I implemnted the command at the same time
%D as I changed the user interface.
%D 
%D Untill the old definition for \tex{setupletter} remains in \filename{t-letter.tex}
%D I have to redefine also \tex{lettervalue}, \tex{doiflettervalue} and
%D \tex{doifelselettervalue} because the old and new definitions differe in the
%D number of arguments but the new definition will move to the core file as soon
%D as I replace \tex{setupletter} in the core.

%D \starttyping
%D \def\setupletter
%D   {\dodoubleempty\dosetupletter}
%D 
%D \def\dosetupletter[#1][#2]%
%D   {\ifsecondargument
%D      \dodosetupletter[#1][#2]%
%D    \else
%D      \dodosetupletter[#1][]%
%D    \fi}
%D 
%D \def\dodosetupletter[#1][#2]%
%D   {\doifelsenothing{#2}
%D      {\getparameters[\????ld][#1]}
%D      {\def\dododosetupletter##1%
%D         {\getparameters[\????ld##1][#2]}%
%D       \processcommalist[#1]\dododosetupletter}}
%D 
%D \def\lettervalue#1%
%D   {\csname\????ld#1\endcsname}
%D 
%D \def\doiflettervalue#1%
%D   {\doiftextelse{\lettervalue{#1}}
%D      \firstofoneargument
%D      \gobbleoneargument}
%D 
%D \def\doifelselettervalue#1%
%D   {\doiftextelse{\lettervalue{#1}}
%D      \firstoftwoarguments
%D      \secondoftwoarguments}
%D 
%D \definecomplexorsimple\setlettervalue
%D 
%D \def\complexsetlettervalue[#1]#2%
%D   {\setvalue{\????ld#1}{#2}}
%D 
%D \def\simplesetlettervalue#1#2%
%D   {\setvalue{\????ld#1}{#2}}
%D \stoptyping

%D \subject{Letter environment}
%D 
%D \macros
%D   {startletter}
%D 
%D The main macro in this file, it is used to write the letter content.
%D It is also possible to set the address and a few other values like
%D the opening and closing with the optional argument, the values are
%D local in this case and not global like the values you could set with
%D \tex{setupletter}.
%D 
%D \showsetup{startletter}

\def\startletter
  {\bgroup\dodoubleempty\dostartletter}

\def\dostartletter[#1][#2]%
  {\ifsecondargument
     \setupletter[#1]%
     \doifundefinedelse{\????ld\????ld#2}
       {\setvalue{\????ld\c!toaddress}{#2}}
       {\setvalue{\????ld\c!toaddress}{\getvalue{\????ld\????ld#2}}}%
   \else\iffirstargument
     \doifassignmentelse{#1}
       {\setupletter[#1]}
       {\doifundefinedelse{\????ld\????ld#1}
          {\setvalue{\????ld\c!toaddress}{#1}}
          {\setvalue{\????ld\c!toaddress}{\getvalue{\????ld\????ld#1}}}}%
   \fi\fi
   \def\stopletter
     {\setups[letter:place]\egroup
      \setupsubpagenumber[\c!state=\@@@@lsoptionstate]}%
   \dostartbuffer[lettercontent][startletter][stopletter]}

%D Patched version of the \tex{flushbufferline} macro for \MKII,
%D the changes are definition as long and removing of \tex{string}
%D in the argument of the last write block.

\long\def\flushbufferline#1%
  {\iftmpblockstarted
     \ifsegmentatebuffer
       \ifemptybufferline
         \immediate\write\tmpblocks{\string\stopbufferparagraph }%
         \immediate\write\tmpblocks{\string\startbufferparagraph}%
       \else
         \immediate\write\tmpblocks{#1}%
       \fi
     \else
       \immediate\write\tmpblocks{#1}%
     \fi
   \else
     \doifsomething{#1}
       {\tmpblockstartedtrue
        \immediate\write\tmpblocks{#1}}%
   \fi}

%D \macros
%D   {startlettercontent}
%D 
%D The letter content is saved in the value content, although I could
%D place it in the corresponding I prefer this solution because you could
%D now use it in your own macros and redefine the content setups to your
%D own wishes.

\setupletter
  [\c!content={\getbuffer[lettercontent]}]

\def\startlettercontent
  {\dostartbuffer[lettercontent][startlettercontent][stoplettercontent]}

%D After the definition of all macros I could now put the content
%D in the corresponding setups, this is only important if you want
%D to define your own layout for header, address etc.

\setvalue{\v!letter:\v!head:\v!a}%
  {\lettervalue\c!fromname
   \doiflettervalue\c!fromname\\
   \lettervalue\c!fromaddress}

\startsetups[letter:head]
\def\\{\letterstylevalue\v!head\c!separator}%
\executeifdefined{\v!letter:\v!head:\@@@@lsheadalternative}{\getvalue{\v!letter:\v!head:\v!a}}%
\stopsetups

\startsetups[letter:foot]
\executeifdefined{\v!letter:\v!foot:\@@@@lsfootalternative}\donothing
\stopsetups

\startsetups[letter:nexthead]
\executeifdefined{\v!letter:\v!nexthead:\@@@@lsnextheadalternative}\donothing
\stopsetups

\startsetups[letter:nextfoot]
\executeifdefined{\v!letter:\v!nextfoot:\@@@@lsnextfootalternative}\donothing
\stopsetups

\setvalue{\v!letter:\v!header:\v!fullblock}%
  {\hbox\!!to\hsize
     {\rlap{\lettervalue\c!toname}%
      \midaligned{\pagenumber}%
      \llap{\framed[\c!frame=\v!off,\c!location=\v!top,\c!align=\v!left]
        {\lettervalue\c!date   \\
         \lettervalue\c!reference}}}}

\setvalue{\v!letter:\v!header:\v!hanging}%
  {\hbox\!!to\hsize
     {\framed[\c!frame=\v!off,\c!location=\v!top,\c!align=v!right]
       {\lettervalue\c!toname    \\
        \lettervalue\c!date      \\
        \lettervalue\c!reference \\
        \labeltext{page}\pagenumber}}\hss}

\copycsname\v!letter:\v!header:\v!modified\endcsname\csname\v!letter:\v!header:\v!hanging\endcsname

\startsetups[letter:header]
\executeifdefined{\v!letter:\v!header:\@@@@lsheaderalternative}\donothing
\stopsetups

\startsetups[letter:footer]
\executeifdefined{\v!letter:\v!footer:\@@@@lsfooteralternative}\donothing
\stopsetups

%D \subject{Addressee field}
%D 
%D The address field is separated into two different fields.
%D The upper field is meant for dispatch information, the official height
%D in germany is 3 lines but this would lead to different heights dependent
%D of the font size and the fonts own height. The lower field contains the
%D name and address of the receiver and has a height of 6 lines in germany.
%D This value will lead to the same problem as the upper field, because the
%D whole address field has a fixed height and both field should fit into
%D this space. I solved this problem by assinging the upper field 1/3 of the
%D address height and the lower field 2/3 of the address height.
%D 
%D If you hace problem to put all information in the limited space you could
%D try to reduce the font size or reduce the interlinespace in the field.

\presetlocalframed[\????ls\v!dispatch]
\presetlocalframed[\????ls\v!addressee]

\startsetups[letter:place:dispatch]

  \localframed
    [\????ls\v!dispatch]
    {\doadaptleftskip {\letterstylevalue\v!dispatch\c!leftmargin}%
     \doadaptrightskip{\letterstylevalue\v!dispatch\c!rightmargin}%
     \doattributes{\????ls\v!dispatch}\c!style\c!color{\setups[letter:address:dispatch]}}

\stopsetups

\startsetups[letter:place:addressee]

  \localframed
    [\????ls\v!addressee]
    {\doadaptleftskip {\letterstylevalue\v!addressee\c!leftmargin}%
     \doadaptrightskip{\letterstylevalue\v!addressee\c!rightmargin}%
     \doattributes{\????ls\v!addressee}\c!style\c!color{\setups[letter:address:content]}}

\stopsetups

\setvalue{\v!letter:\v!address:\v!a}%
  {\doif\@@@@lsoptiondispatch \v!yes{\setups[letter:place:dispatch]}%
   \doif\@@@@lsoptionaddressee\v!yes{\setups[letter:place:addressee]}}

\startsetups[letter:address]
\offinterlineskip\vskip-\lineheight
\executeifdefined{\v!letter:\v!address:\@@@@lsaddressalternative}{\getvalue{\v!letter:\v!address:\v!a}}%
\stopsetups

\startsetups[letter:address:dispatch]
\lettervalue\c!dispatch
\stopsetups

\startsetups[letter:address:content]
\def\\{\letterstylevalue\v!address\c!separator}%
\lettervalue\c!toname
\doiflettervalue\c!toname\\
\lettervalue\c!toaddress
\stopsetups

%D The following setups shouldn't be changed ar you will loose information
%D in the output.
%D 
%D The reference line is choosen with the alternative key or if you set
%D a not defined alternative the definition a is choosen.

\startsetups[letter:reference]
\executeifdefined{\v!letter:\v!reference:\@@@@lsreferencealternative}{\getvalue{\v!letter:\v!reference:\v!a}}
\stopsetups

\resetvalue{\v!letter:\v!location:\v!a}

\setvalue{\v!letter:\v!location:\v!french}%
  {\lettervalue\c!place
   \doiflettervalue\c!place{\lettervalue{\c!place\c!separator}}%
   \lettervalue\c!date}

\startsetups[letter:location]
\executeifdefined{\v!letter:\v!location:\@@@@lslocationalternative}{\getvalue{\v!letter:\v!location:\v!a}}
\stopsetups

\startsetups[letter:title]
\doifelselettervalue\c!title
  {\lettervalue\c!title}
  {\doiflettervalue\c!attention
     {\labeltext{\v!letter:\c!attention}\lettervalue\c!attention}}
\stopsetups

\startsetups[letter:subject]
\def\\{\letterstylevalue\v!subject\c!separator}%
\labeltext{\v!letter:\c!subject}\lettervalue\c!subject
\stopsetups

\setvalue{\v!letter:\v!opening:\v!a}%
  {\doifelselettervalue\c!opening
     {\lettervalue\c!opening}
     {\doiflettervalue\c!salutation
        {\lettervalue\c!salutation}}}

\setvalue{\v!letter:\v!opening:\v!french}%
  {\ExpandSecondAfter\doifsomething{\letterstylevalue\v!option\c!indenting}
     {\setupindenting[\@@@@lsoptionindenting]}%
   \getvalue{\v!letter:\v!opening:\v!a}}

\startsetups[letter:opening]
\executeifdefined{\v!letter:\v!opening:\@@@@lsopeningalternative}{\getvalue{\v!letter:\v!opening:\v!a}}
\stopsetups

\startsetups[letter:content]
\lettervalue\c!content
\stopsetups

%D \subject{Closing and appendices}
%D 
%D It is possible to attach a signature to the closing command, before the signature
%D a skip is inserted but only if the the signature key has a value. The height of the
%D closing environment itself has a height of 4 lines to provide a free space for your
%D own handwritten signature and to have a little bit space between the closing text
%D and the appendices.

\setvalue{\v!letter:\v!closing:\v!a}%
  {\lettervalue\c!closing
   \doiflettervalue\c!signature{\letterstylevalue\v!closing\c!inbetween}%
   \lettervalue\c!signature}

\setvalue{\v!letter:\v!closing:\v!french}%
  {\ExpandSecondAfter\doifsomething{\letterstylevalue\v!option\c!indenting}
     {\setupindenting[\@@@@lsoptionindenting,\v!first]}%
   \lettervalue\c!closing
   \doiflettervalue\c!signature{\letterstylevalue\v!closing\c!inbetween}%
   \raggedcenter\doadaptleftskip{.5\textwidth}% quick and dirty
   \lettervalue\c!signature\endgraf}

\setvalue{\v!letter:\v!closing:\v!simplified}%
  {\doiflettervalue\c!signature{\letterstylevalue\v!closing\c!inbetween}%
   \lettervalue\c!signature}

\startsetups[letter:closing]
\def\\{\letterstylevalue\v!closing\c!separator}%
\executeifdefined{\v!letter:\v!closing:\@@@@lsclosingalternative}{\getvalue{\v!letter:\v!closing:\v!a}}%
\stopsetups

\startsetups[letter:appendices]
\let\\\crlf
\doflushletterdescription
\stopsetups

\dodefineletterdescription[\v!enclosure]

\startsetups[letter:enclosure]
\processaction
  [\lettervalue\c!enclosure]
  [  \v!empty=>\vrule\!!height\zeropoint\!!depth\zeropoint\!!width\hsize\relax\ifvmode\nowhitespace\fi,
   \s!unknown=>\lettervalue\c!enclosure]
\stopsetups

\dodefineletterdescription[\v!copy]

\startsetups[letter:copy]
\processaction
  [\lettervalue\c!copy]
  [  \v!empty=>\vrule\!!height\zeropoint\!!depth\zeropoint\!!width\hsize\relax\ifvmode\nowhitespace\fi,
   \s!unknown=>\lettervalue\c!copy]
\stopsetups

\dodefineletterdescription[\v!postscript]

\startsetups[letter:postscript]
\processaction
  [\lettervalue\c!postscript]
  [  \v!empty=>\vrule\!!height\zeropoint\!!depth\zeropoint\!!width\hsize\relax\ifvmode\nowhitespace\fi,
   \s!unknown=>\lettervalue\c!postscript]
\stopsetups

\setvalue{\v!letter:\v!backaddress:\v!yes}%
  {\lettervalue\c!fromname
   \doiflettervalue\c!fromaddress\\
   \lettervalue\c!fromaddress}

\resetvalue{\v!letter:\v!backaddress:\v!no}

\setvalue{\v!letter:\v!backaddress:\v!auto}%
  {\doifelselettervalue\c!backaddress
     {\lettervalue\c!backaddress}
     {\lettervalue\c!fromname
      \doiflettervalue\c!fromaddress\\
      \lettervalue\c!fromaddress}}

\startsetups[letter:backaddress]
\def\\{\letterstylevalue\c!backaddress\c!separator}%
\executeifdefined{\v!letter:\v!backaddress:\@@@@lsbackaddressalternative}{\getvalue{\v!letter:\v!backaddress:\v!no}}%
\stopsetups

%D To prevent a pagebreak between the last line of the text and
%D the siganture a nonbreakable vertical space is necessary.
%D The vertical space is inserted in the style file with the normal
%D before and after commands where we control the distance between
%D the elements.

\defineblankmethod [\v!nobreak] {\penalty\plustenthousand}
\defineblankmethod [\v!endgraf] {\endgraf}

%D \subject{Additional settings}
%D 
%D I set alternative a as default value for alternative, the only content
%D is the date with a label. f you dont want a label choose alternative c
%D or change the label.

\startsetups[letter:optimize]

  \setbox\scratchbox\hbox % trial typesetting to get the heigth of the reference line
    {\executeifdefined{\v!letter:\v!reference:\@@@@lsreferencealternative}{\getvalue{\v!letter:\v!reference:\v!a}}}

  %\setups[letter:reference:\@@@@lsreferencealternative]

\stopsetups

%D We have at the moment only the values from the core module, I use the settings
%D from the dinb file as default settings, you could replace them in your own
%D document but I won't change the default style.
%D 
%D The labels are stored in a common file, you could use them in your own interface
%D but you have to live with my names.

\useletterstyle    [dinb]    % layout
\useletterextension[label]   % labels

\protect \endinput