%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-5-45 on page I-235 in "marginnote --- An alternative to \protect \nxLcs  {marginpar}".
%%
%% 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{159.0pt}


\hyphenation{side-notes}

\setcounter{page}{1}
\addtolength\textwidth{-70pt}
\setlength\marginparwidth{58pt}

%StartShownPreambleCommands
\usepackage{xcolor,marginnote}
%StopShownPreambleCommands

\begin{document}
Issue\marginnote{First} with\marginnote{\color{blue}A
   longer second} sidenotes getting too close to
each other.\marginnote{Third}

Issue\marginnote{First} with\marginnote{\color{blue}A
  longer second}[12pt] sidenotes getting too close to
each other.\marginnote{Third}
A bit more text for the main galley.
\end{document}