%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-3-10 on page I-160 in "Formatting acronym texts".
%%
%% 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{111.0pt}
\setlength\parindent{0pt}
\raggedright
%StartShownPreambleCommands
\usepackage[english,ngerman]{babel}  \usepackage{acro}
\acsetup{format/short=\textlsc, format/foreign=\itshape}
\DeclareAcronym{etc}{short=etc.\@, long=et cetera,
                     short-format= }   % overwriting default
\DeclareAcronym{cd}{short = CD\@, long = Compact Disc}
\DeclareAcronym{lp}{short = LP\@, long = Langspielplatte,
  foreign = Long Playing Vinyl Record, foreign-babel = english}
\newcommand\textlsc[1]{\textsc{\MakeLowercase{#1}}}
%StopShownPreambleCommands

\begin{document}
\ac{cd} \\ \ac{lp} \\  \ac{etc}
\end{document}