The list of filters has gotten too long, the filters are often not self-explanatory and all the tooltips only repeat the names of the filters.
Ideally we would only offer a few important filters with helpful tooltips and add a function for adding self made filters.
I am giving this wishlist priority for now.
For the current filters we would need a list of the names and what kind of filters they should use. Most filters are defined in libkleopatrarc. But honestly I think replacing the preset filters with a little "filter" menu that exposes the KConfigBasedKeyFilter rules to the user would just make the most sense. But this is a little bigger task, so wishlist for now.
Ingo came up with the idea to put all the filter definitions in a config file in the GNUPGHOME.
This way has the advantage that the definitions can be easily reviewed and that one could customize these in case of special needs.
My suggestion is to define all filters in libkleopatrarc instead of defining some filters in the C++ code.