%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-6-1 on page I-238 in "todonotes --- Adding todos to your document".
%%
%% 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{219.0pt}

 \setlength\marginparwidth{70pt}
 \addtolength\textwidth{-\marginparwidth}   % make room on the page
 \addtolength\textwidth{-2\marginparsep}    % in the book example

 % small headings for the example
 \makeatletter
 \renewcommand\section{\@startsection{section}{1}{\z@}%
   {-1.25ex \@plus-1ex \@minus-.2ex}%
   {.5ex}%
   {\normalfont\large\bfseries}}
 \makeatother

 \usepackage{microtype}  % improve h&j in example

%StartShownPreambleCommands
\usepackage[colorinlistoftodos]{todonotes}
%StopShownPreambleCommands

\begin{document}
These\todo{Make nicer example} are real
notes from early drafts of this
section.

\todo{Discuss the available keys}
\listoftodos[My todos]
\end{document}