A normal regexp to allow letters only would be \"[a-zA-Z]\" but I\'m from, Sweden so I would have to change that into \"[a-zåäöA-ZÅÄÖ]\". But suppose I don
Matches any character in the named character class specified by {name}.
Supported names are Unicode groups and block ranges. For example, Ll, Nd, Z,
IsGreek, IsBoxDrawing.
I don't know enough about unicode, but maybe your characters fit a unicode class?