There is probably not a way to have the Forum software differentiate between
vB code/html and characters.
The reason that there is a limit on signature length is because some people had annoying 25 line signatures.
A bunch of us old timers campaigned to have a limit put on signatures.
I voted for five lines.
I don't know if 200 characters was decided on by Paul as a reasonable limit, or if the software does not allow a line limit, only a characters per field limit. If this is the case, perhaps we could petition Paul to increase it to 300 characters?