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.
If you are going to proceed:
\captioncommand, that doesn't have the footnote in it; this prevents the footnote appearing in the “List of …”, and
minipageso as to keep the footnotes with the float.
so we have:
So, we make an entry for the List of Figures, which doesn't hold
troublesome commands, such as
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
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.