Footnotes in captions

Footnotes in captions are especially tricky: they present problems of their own, on top of the problems one experiences with footnotes in section titles (footnotes migrating to to the list of figures or tables, or apparently random errors because \footnote is a fragile command), and with footnotes in tables (typically, the footnote simply disappears). Fortunately, the requirement for footnotes in captions is extremely rare: if you are experiencing problems, it is worth reviewing what you are trying to say by placing this footnote: other options are to place text at the bottom of the float, or to place a footnote at the point where you refer to the float.

Note that the threeparttable scheme (see, again, footnotes in tables) also applies to notes in captions, and may very well be preferable to whatever you were thinking of.

If you are going to proceed:

• use an optional argument in your \caption command, that doesn’t have the footnote in it; this prevents the footnote appearing in the “List of …”, and
• put your whole float in a minipage so as to keep the footnotes with the float.

so we have:

\begin{figure}
  \begin{minipage}{\textwidth}
    ...
    \caption[Compact Routing Example]%
    {Compact Routing\footnote{something} Example}
  \end{minipage}
\end{figure}

So, we make an entry for the List of Figures, which doesn’t hold troublesome commands, such as \footnote.

However, as well as all of the above, one also has to deal with the tendency of the \caption command to produce the footnote’s text twice. For this last problem, there is no tidy solution this author is aware of.

If you’re suffering the problem, a well-constructed \caption command in a minipage environment within a float (as in the example above) can produce two copies of the footnote body “something”. (In fact, the effect only occurs with captions that are long enough to require two lines to be typeset, and so wouldn’t appear with such a short caption as that in the example above.)

The documentation of the ccaption package describes a really rather awful work-around for this problem.

FAQ ID: Q-ftncapt
Tags: footnotes