RAF - Regular people being paid to do their job. Fight wars (or LEAN)
RAFAux or RAAuxF - The RAF's TA
RAFVR(T) - Run the Air Cadet Organisation
RAFR - Usually (but not always) retired or ex-RAF people, employed as (I think) J class reserve. Civil servants, limited call up liability - NOT, by any stretch of the imagination the "real" RAF. For example, generally all ATC Wing AdO's are J Class RAFR's - Ours is an ex-Wing Cdr Rock, and bloody good at his job he is too.