You have to keep in mind the provided scripting language has its own syntax and special chars.
It is recommended to put especially regex patterns in ' apostrophes so you don't have to escape each ( or [ character.
Try $regexp(%title%,'([a-z])+',_)
Still no luck... I don't get it. $regexp(%title%,'([A-Z][a-z]\xdc\xfc\d\s)+',_)
is producing nothing. Shouldn't ([A-Z][a-z]\xdc\xfc\d\s)+ select Drüg, feat and Emie?
Afaik ([A-Z][a-z])+ finds every word that consists of uppercase and lowercase letters ranging from a to z. But in mp3tag literally nothing gets found or replaced at all. What am I missing? I am losing my believe in myself.
I found the solution... I have to include the | OR operator: $regexp(%title%,'([A-Z]|[a-z])+',_)
Now I can sleep in peace.
Maybe instead of $regexp(%title%,'([A-Z][a-z]\xdc\xfc\d\s)+',_)
you meant $regexp(%title%,'([A-Za-z\xdc\xfc\d\s])+',_)
Understand the difference [A-Z][a-z] vs [A-Za-z]