Grouping prefixes in mandatory / optional

[smallwheels]

in my forum we do have a marketplace. Within, prefixes for new threads are mandatory to distinguish between "offering" and "wanted". It would however be helpful to be able to use additional prefixes optionally to characterize the item (i.e. boat, car. etc.). As atm it is only possible to require a prefix or not but not having a set for mandatory prefixes plua an additional of optional ones I am limited to the base set.

So it would be cool to have the option for prefix groups for multi prefix for a certain subforum and to be able to set wether each group is mandatory or optional for that subforum.