%%
%% The LaTeX Companion, 3ed
%%
%% Example 2-4-1 on page I-75 in "Managing references".
%%
%% 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{207.0pt}

  \setcounter{section}{3}

  \makeatletter
  \renewcommand\section{\@startsection {section}{1}{\z@}%
    {-2.5ex \@plus -1ex \@minus -.2ex}%
    {1.3ex \@plus.2ex}%
    {\normalfont\Large\bfseries}}
  \makeatother

%StartShownPreambleCommands

%StopShownPreambleCommands

\begin{document}
\section{A Section} \label{sec:this}

A reference to this section looks
like this:  ``see section~\ref{sec:this}
on page~\pageref{sec:this}''.
\end{document}