"LaTeX Warning: Label `1' multiply defined." with twoside document and option `margin`
Using option `margin` with two different values in a `twoside` document results in:
```log
LaTeX Warning: Label `1' multiply defined.
```
Here a minimal working example:
```latex
\documentclass[twoside]{article}% option twoside needed
\usepackage[margin={0cm,1cm}]{caption}% option margin with two different values needd
\usepackage{mwe}
\begin{document}
\begin{figure}
\includegraphics{example-image}
\caption{Test}% also happens with \caption* instead of \caption
\end{figure}
\end{document}
```
and the message after two LaTeX runs:
```log
(./captionissue.aux
LaTeX Warning: Label `1' multiply defined.
)
```
issue