Hi Felix,
>> So, with every '&' the System went wrong. Is there an easy way to
>> mask '&' instead of replacing it with '&'?
>
> Use gobject.markup_escape_text:
>
> gobject.markup_escape_text("This & <That>")
> # --> 'This & <That>'
That's the thing I was looking for.
Thanks,
Volker