%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-3-7 on page I-159 in "One-time usage of acronyms".
%%
%% 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{135.0pt}

  \setlength\parindent{8pt}

%StartShownPreambleCommands
\usepackage{acro}  \acsetup{single=2,single-style=short}
\DeclareAcronym{hg}{short = \mbox{THGTTG}, long = the
           Hitchhiker's Guide to the Galaxy}
\DeclareAcronym{ufo}{short = UFO\@, long = unidentified
           flying object, single = Zaphod Beeblebrox}
%StopShownPreambleCommands

\begin{document}
\Ac{hg} and  \Acf*{ufo}, \acs{ufo} and \ac{ufo}
\end{document}