Adding todo inside a caption

Question

I am using the todonotes package and I wanted to add a note inside a caption like:

\caption{This is the section heading\todo{We should rethink the section title.}}

However, this is throwing the “Not in outer par mode” error. I understand why, but I wonder if there is a way to do this.

Thanks.

Answer 1

As far as I know \todo does not work in a caption, but \todo[inline] will do, however, the remark text is not in the margin!

\documentclass{article}

\usepackage{todonotes}

\begin{document}

\begin{figure}
\caption{This is the section heading\todo[inline]{We should rethink the section title.}}
\end{figure}
\end{document}

Answer 2

This may or may not be useful, but the luatodonotes package works in captions. It requires the use of lualatex for compiling the document though.

\documentclass{article}
\usepackage{luatodonotes}
\begin{document}
\begin{figure}
\caption{This is the section heading\todo{We should rethink the section title.}}
\end{figure}
\end{document}

Answer 3

You can add a todo (not only todo[inline], but todo in margins) inside floating environments (like table, figure, etc). You just need to add the following patch:

\usepackage{marginnote}
\let\marginpar\marginnote

Source: the todonotes package manual http://tug.ctan.org/macros/latex/contrib/todonotes/todonotes.pdf section 1.6.9.

I have tested your code with this patch and it works correctly. Although 4 years have passed since this question was asked I post the solution here in case someone need it in the future, like myself today.