If I knew Vanity Transponder Codes were a thing I would have tried this long ago: The Fort St. John (YXJ) flight service station (FSS) informed the Edmonton (YEG) flight information centre (FIC) that a XXXX Helicopters Ltd. Bell 206B required a transponder code ending in a “0”. After questioning the pilot and the FSS, it was determined that the pilot had an unserviceable (U/S) transponder.