+\def\@setf{setf}
+\def\@starstar{**}
+
+%% \parse@dhd{NEXT}[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%%
+%% Parse the arguments for a description header, and call
+%%
+%% NEXT{MOD}{CAT}{{...}...}{NAME}{SYNOPSIS}
+%%
+%% Here, {...}... represents the additional category-kind arguments. See
+%% `describe' for what all of this means.
+\def\parse@dhd#1{% {NEXT}
+ \@ifnextchar[{\parse@dhd@a{#1}}{\parse@dhd@c{#1}}}
+\def\parse@dhd@a#1[#2]#3{% {NEXT}[MOD]{CAT}
+ \@desc@dispatch{descargs}{#3}{\parse@dhd@ab{#1}{#2}{#3}}}
+\def\parse@dhd@ab#1#2#3#4{% {NEXT}{MOD}{CAT}{{...}...}
+ \@ifnextchar[{\parse@dhd@ac{#1}{#2}{#3}{#4}}{\parse@dhd@ad{#1}{#2}{#3}{#4}}}
+\def\parse@dhd@ac#1#2#3#4[#5]#6{% {NEXT}{MOD}{CAT}{{...}...}[NAME]{SYNOPSIS}
+ #1{#2}{#3}{#4}{#5}{#6}}
+\def\parse@dhd@ad#1#2#3#4#5{% {NEXT}{MOD}{CAT}{{...}...}{NAME [ARGS...]}
+ \parse@dhd@ae{#1}{#2}{#3}{#4}{#5}#5 \q@}
+\def\parse@dhd@ae#1#2#3#4#5#6 #7\q@{%
+ % {NEXT}{MOD}{CAT}{{...}...}{SYNSOPSIS}NAME [ARGS...]\q@
+ #1{#2}{#3}{#4}{#6}{#5}}
+
+\def\parse@dhd@c#1#2{% {NEXT}{CAT}
+ \@desc@dispatch{descargs}{#2}{\parse@dhd@cb{#1}{#2}}}
+\def\parse@dhd@cb#1#2#3{% {NEXT}{CAT}{{...}...}
+ \@ifnextchar[{\parse@dhd@cc{#1}{#2}{#3}}{\parse@dhd@cd{#1}{#2}{#3}}}
+\def\parse@dhd@cc#1#2#3[#4]#5{% {NEXT}{CAT}{{...}...}[NAME]{SYNOPSIS}
+ #1{}{#2}{#3}{#4}{#5}}
+\def\parse@dhd@cd#1#2#3#4{% {NEXT}{CAT}{{...}...}{SYNOPSIS}
+ \parse@dhd@ce{#1}{#2}{#3}{#4}#4 \q@}
+\def\parse@dhd@ce#1#2#3#4#5 #6\q@{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}NAME [ARGS...]\q@
+ \def\temp@{#5}%
+ \ifx\@setf\temp@\def\next@{\parse@dhd@csetf{#1}{#2}{#3}{#4}#6 \q@}%
+ \else\def\temp@##1##2*##3\q@{\def\temp@{##1##3}}\temp@#5*\q@%
+ \ifx\temp@\@starstar\def\next@{\parse@dhd@cmuffs{#1}{#2}{#3}{#4}#5}%
+ \else\def\temp@##1##2\q@{\def\temp@{##1}}\temp@#5\q@%
+ \if:\temp@\def\next@{\parse@dhd@ckwd{#1}{#2}{#3}{#4}#5\q@}%
+ \else\def\next@{#1{}{#2}{#3}{#5}{#4}}\fi\fi\fi%
+ \next@%
+}
+\def\parse@dhd@csetf#1#2#3#4(#5 #6\q@{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}(NAME [ARGS...])\q@
+ #1{setf}{#2}{#3}{#5}{#4}}
+\def\parse@dhd@cmuffs#1#2#3#4*#5*{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}*NAME*
+ #1{muffs}{#2}{#3}{#5}{#4}}
+\def\parse@dhd@ckwd#1#2#3#4:#5\q@{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}:NAME\q@
+ #1{kwd}{#2}{#3}{#5}{#4}}
+
+%% \dhead[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%%
+%% Typeset a description head. Use this within the first argument of
+%% `describe*'; see `describe' for the details.
+\newif\if@dheadfirst
+\def\dhead{\parse@dhd\dhead@}
+\def\dhead@#1#2#3#4#5{% {MOD}{CAT}{{...}...}{NAME}{SYNOPSIS}
+ \if@dheadfirst\global\@dheadfirstfalse\else\relax\\*[\smallskipamount]\fi%
+ \phantomsection%
+ {\let\protect\@empty\let\@uscore\relax%
+ \edef\temp@{\@desc@dispatch{desclabel}{#2}{#2}{#1}{#4}#3}%
+ \def\@uscore{_\@gobble}\expandafter\message\expandafter{\temp@}%
+ \def\@uscore{-\@gobble}\expandafter\label\expandafter{\temp@}}%
+ {\begingroup\lccode`\~=`\_\lowercase{\endgroup\def~{_}}%
+ \protected@edef\@tempa##1{%
+ \noexpand\index{\@desc@dispatch{descindex}{#2}{#2}{#1}{#4}#3##1}}%
+ \toks@\expandafter{\@tempa{|)}}%
+ \toks\tw@\expandafter{\after@desc}%
+ \xdef\after@desc{\the\toks\tw@\the\toks@}%
+ \@tempa{|(}}%
+ \rlap{\hb@xt@\linewidth{\hfil\normalfont\bfseries
+ [\describecategoryname[#1]{#2}]}}%
+ #5%
+}
+
+%% Main guts of a description environment. The argument here typesets the
+%% header line(s).
+\def\desc@begin#1{%
+ \let\saved@after@desc\after@desc%
+ \gdef\after@desc{}%