The RAF does not need to recognise a thing.
You join or rejoin the services it will be at their pleasure. No sabbatical from BA. You will be subject to military law. No unions. You piss them off and 6 months to a year in charge of Bog roll in Benbeccula. They won't give a **** that your position has come up again at BA and you need to leave. You take the queen's shilling and you do their bidding. You will then realise that you have been shafted by professionals. Rather you than me.