When I worked in a school in the East End in the glory days of ILEA and Red Ken, we got a new headmaster who'd clearly been used to his rather formal posh Edinburgh school's ways. He decided to call us all by surnames only. One day he was hailing my mate Terry Hunter from behind in the corridor: "A word with you please, Hunter!" Tel stopped momentarily in his tracks but didn't turn round, then proceeded purposefully on his way. "Er, Mr Hunter...!" did the trick for the head. That cured him of that little habit!