Having flown out of MAN alot I was very used to only passing call sign to director when passed over, as they always said 'callsign only'. However, once flying into LGW, I was asked to contact director without the requirement of callsign only. This is what I did however, and was promptly put in my place by the director, asking for cleared level etc....
So, I just do what Im told, if they ask callsign only thats whats I'll do, if not then make a standard call.