I think it was only banned on the original BBS - the one in force at the time of Doyles takeover because there was some unpleasantness when BBSv2 was launched he was long gone so no need to add it to the ****ing swear filter
It did make me laugh at the time that someone got around the filter with the brilliantly conceived Mr P. Turdoil. Subsequently tying to explain it to a non-Yorkshire person proved a bit of a challenge though.