%%
%% The LaTeX Companion, 3ed
%%
%% Example 2-2-22 on page I-54 in "Formatting headings --- \LaTeX 's internal low-level methods".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See
https://www.latex-project.org/lppl.txt for details.
%%
\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.0pt}
\makeatletter
\renewcommand\appendix{%
\renewcommand\section{% Redefinition of \section...
\newpage\thispagestyle{plain}% new page, folio bottom
\suppressfloats[t]\@afterindentfalse% no top floats, no indent
\secdef\Appendix\sAppendix}%
\setcounter{section}{0}\renewcommand\thesection{\Alph{section}}}
\newcommand\Appendix[2][?]{% Complex form
\refstepcounter{section}%
\addcontentsline{toc}{appendix}{\protect\numberline{\appendixname~\thesection}#1}%
{\raggedleft\large\bfseries\appendixname\ \thesection\par \centering#2\par}%
\@afterheading\sectionmark{#1}\addvspace{\baselineskip}}
\newcommand\sAppendix[1]{% Simplified (starred) form
{\raggedleft\large\bfseries\appendixname\par \centering#1\par}%
\@afterheading\addvspace{\baselineskip}}
\makeatother
%StartShownPreambleCommands
% Example needs commands introduced above!
%StopShownPreambleCommands
\begin{document}
\appendix
\section{The list of all commands}
Then follows the text of the first section in
the appendix. Some more text in the appendix.
\end{document}
