There is also an "A300-B4 FF" rating which is for the few A300-B4's with two crew. (FF=forward facing)
In a previous life our HR dept. took on a contract Capt. with the FF rating. We were very short of Capts. at the time and it was thought he would be on line in a week or so. It took 4 months to get him rated.
Happy landings.