%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-1-21 on page I-272 in "The placement of the item label or item text".
%%
%% 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}
\usepackage{enumitem}
\SetLabelAlign{right}{\hss\setlength\fboxsep{0pt}\framebox[\labelwidth][r]{\strut\llap{#1}}}
%StartShownPreambleCommands
\usepackage{enumitem}
\setlist[enumerate]{label=--\arabic*--}
%StopShownPreambleCommands
\begin{document}
\noindent Some text to show the left margin.
\begin{enumerate}
\item The default.
\end{enumerate}
\begin{enumerate}[leftmargin=*,start=2]
\item One digit labels are set flushleft on the margin.
\end{enumerate}
\begin{enumerate}[leftmargin=*,start=33]
\item But labels with 2 digits protrude.
\end{enumerate}
\begin{enumerate}[leftmargin=*,widest=99,start=42]
\item Here we tell to leave space for 2 digits.
\end{enumerate}
\end{document}
