Prevent rt from isolating signature?


I recently added a signature to my (personal) rt user.

RT insisted in isolationg that signature with "-- ", however, I’d like
to prevent that since my signature contains more than the signature
itsself, which is already isolated.

Another Question:
I removed my signature but RT still insists in producing a signature
since there is a 1 byte signature in the database, which appearently
cannot the completely deleted?