Stores the attribute value of the currently processed character (from offset +15 in character data). Read by ReadRoomDisplayParameter, PlaceCharacterBesideMatch, PrintMessageAndInitialiseTimer, AdvanceGardenerAfterMove, CheckObjectLocationMatch, ProcessDisplayRecord, SetCharacterPointerAndID, DescribeCurrentRoom, ParseInputNumber, CheckCharacterID, StoreMatchedCharacterRoom, MeasureGapBetweenTwoPointers_Next, SpecialCaseObject_LooksBasilPhipps, PlaceCharacter and FindResponseForThisId.