%%
%% The LaTeX Companion, 3ed
%%
%% Example 2-3-2 on page I-57 in "tocdata --- Providing extra data for the TOC".
%%
%% 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{207.0pt}


  % small headings for the example
  \makeatletter
  \renewcommand\section{\@startsection{section}{1}{\z@}%
    {-1.25ex \@plus-1ex \@minus-.2ex}%
    {.5ex}%
    {\normalfont\large\bfseries}}
  \renewcommand\subsection{\@startsection {subsection}{2}{\z@}%
    {-1.ex \@plus -.5ex \@minus -.2ex}%
    {.3ex}%
    {\normalfont\bfseries}}
  \makeatother

%StartShownPreambleCommands
\usepackage{color,tocdata}
\renewcommand\tocdataformat[1]{\textnormal{%
    \textcolor{blue}{--- \small\itshape#1}}}
%StopShownPreambleCommands

\begin{document}
\tableofcontents

\section{On Cookies}
\tocdata{toc}{Ben User}
\subsection{Preparing cookies}
Text of his recipes \ldots

\tocdata{toc}{Cookie Monster}
\subsection{Eating cookies}
How to do it \ldots
\end{document}