[Tex/LaTex] Subcaption package: compatibility issue

incompatibilitypackagessubcaptiontemplates

There is a compatibility problem between the CIFA document class
and the subcaption package.
When I compile the following example (with PDFLaTex):

\documentclass{cifa}

\usepackage{subcaption}

\begin{document}
\begin{figure}
\parbox{4cm}{\subcaption{This is a subcaption}\label{sub}}

\caption{nothing}
\label{nothing}
\end{figure}

See figure \ref{nothing}: there is \ref{sub} inside...

\end{document}

These warnings are displayed:

Package caption Warning: Unsupported document class (or package)
detected,

Package caption Warning: \caption will not be redefined since it's
already

In addition the words "figure" and "subfigure" are displayed
AFTER the captions.

How to fix this issue?

Best Answer

The very recent version of the subcaption package will even issue an error:

! Package caption Error: The `subcaption' package does not work correctly
(caption)                in compatibility mode.

The only way to get around this is to specify the option compatibility=false to the caption package:

\documentclass{cifa}

\usepackage{subcaption}
\captionsetup{compatibility=false}

\begin{document}
\begin{figure}
\parbox{4cm}{\subcaption{This is a subcaption}\label{sub}}
\caption{nothing}
\label{nothing}
\end{figure}

See figure \ref{nothing}: there is \ref{sub} inside...

\end{document}

PLEASE NOTE: This way the customization of the captions done by the cifa document class will be overwritten by the caption package in a brute-force manner. In best case the output of the captions will look different (and some caption-related stuff offered by the cifa document class will not work anymore), in worst case you'll get error messages and weird output. So please also take a look at the caption package documentation, section "6 Package Support". Since this is a perfect method to shoot oneself in the foot, an extra warning is always issued when using the compatibility=false option:

Package caption Warning: Forced redefinition of \caption since the
(caption)                unsupported(!) package option `compatibility=false'
(caption)                was given.
See the caption package documentation for explanation.

If you do not want this (or it does not work anyway) then the only solution left is not-using the subcaption package. Use the subfig package with option caption=false (which prevents loading of the caption package) instead:

\documentclass{cifa}

\usepackage[caption=false]{subfig}

\begin{document}
\begin{figure}
\subfloat[This is a subcaption\label{sub}]{............}
\caption{nothing}
\label{nothing}
\end{figure}

See figure \ref{nothing}: there is \ref{sub} inside...

\end{document}
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