%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-1-20 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}

%StartShownPreambleCommands
  \usepackage{enumitem}
  \setlist{nosep,first=\DrawEnumitemLabel}
%StopShownPreambleCommands

\begin{document}
  \noindent Some text to show the left margin.
  \begin{itemize}
    \item The default.
  \end{itemize}
  \begin{itemize}[labelindent=20pt,itemindent=!]
    \item \texttt{itemindent} now becomes positive.
  \end{itemize}
  \begin{itemize}[labelindent=-10pt,itemindent=!]
    \item \ldots{} and here negative.
  \end{itemize}
\end{document}