[Tex/LaTex] Footnote on “Contents” at head of table of contents

Question

Is it possible to place a footnote on the Contents heading that is generated at the head of a table of contents? (Not on an individual item in the table of contents, as discussed here.)

I thought perhaps titletoc would permit this, but I see nothing about footnotes in the docs for that package.

---

Edit: I am using document class scrbook (needed for \multiplefootmarker, since the author's notes use numbers, while the editor's notes use * and other symbols). It is the editor who needs to annotate the Contents title.

Answer 1

1. book class

Method 1 — Define a new command

The \ftableofcontents command wants as argument the text of the footnote.

\documentclass{book}
\usepackage{xpatch}

\newcommand\ftableofcontents{\renewcommand\ftableofcontents[1]}
\expandafter\ftableofcontents\expandafter{\tableofcontents}
\xpatchcmd\ftableofcontents
  {\contentsname}
  {\contentsname\footnote{#1}\fi}{}{}
% Omit the following lines if you want the footnote with an arabic number
\xpretocmd\ftableofcontents{\begingroup\renewcommand\thefootnote{\fnsymbol{footnote}}}{}{}
\xapptocmd\ftableofcontents{\endgroup}{}{}

\begin{document}
\frontmatter
\ftableofcontents{This is the footnote}

\mainmatter
\chapter{A chapter}
\section{A section}
Here is a footnote\footnote{A}
\end{document}

Method 2 — Overload \tableofcontents

In this case we redefine \tableofcontents to accept as optional argument the text of the footnote; nothing happens if no optional argument is specified.

\documentclass{book}
\usepackage{xpatch}

\newcommand\temp{\renewcommand\tableofcontents[1][]}
\expandafter\temp\expandafter{\tableofcontents}
\xpatchcmd\tableofcontents
  {\contentsname}
  {\contentsname\if\relax\detokenize{#1}\relax\else\footnote{#1}\fi}{}{}
% Omit the following lines if you want the footnote with an arabic number
\xpretocmd\tableofcontents{\begingroup\renewcommand\thefootnote{\fnsymbol{footnote}}}{}{}
\xapptocmd\tableofcontents{\endgroup}{}{}

\begin{document}
\frontmatter
\tableofcontents[This is the footnote]

\mainmatter
\chapter{A chapter}
\section{A section}
Here is a footnote\footnote{A}
\end{document}

2. scrbook class

The previous methods don't work with the scrbook class and it would be very difficult to patch the commands that produce the table of contents, so a hack seems the best thing to try (apart avoiding putting a footnote to a chapter title to begin with).

\documentclass{scrbook}

\begin{document}

\frontmatter

\begingroup
\makeatletter
\protected@edef\contentsname{\contentsname\unexpanded{\footnote{%
  %%%% ADD HERE THE FOOTNOTE TEXT
  This is a footnote%
  %%%% DON'T FORGET THE FINAL %
  }}%
  \gdef\noexpand\contentsname{\contentsname}}

% Omit the following line if you want a number
\renewcommand\thefootnote{\fnsymbol{footnote}}

\tableofcontents
\endgroup

\mainmatter

3. Alternative method (all classes)

Instead of a footnote you can add some text just after the header.

\documentclass{scrbook}

\begin{document}
\frontmatter

\addtocontents{toc}{\unexpanded{\unexpanded{{%
  \itshape\footnotesize
  This is a note for the table of contents
  \par\bigskip
}}}}

\tableofcontents

\mainmatter
\chapter{A chapter}
\section{A section}

\end{document}