%%
%% The LaTeX Companion, 3ed
%%
%% Example A-1-1 on page II-623 in "Command and environment names".
%%
%% 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{159.0pt}
%StartShownPreambleCommands

%StopShownPreambleCommands

\begin{document}
\$ 100 is different from \textdollar 100.
You have to write \$100 to avoid the space!
But \S 1.2 and \S1.2 give the same spacing.
\end{document}