Although we didn’t stand if a Master entered a room, if the Headmaster came in you jumped to your feet and stood to attention until he signalled resumption of seats, even in the middle of a lesson. Unless you were very brave or very bolshie you meant it too. He was the sort of man who could instil fear into 800 boys merely by pausing in the middle of morning assembly and running his eyes over the assembled ranks.
I’ve no idea what form of address the boys at the school use to staff currently. In view of the casual attitude to uniform which now prevails there, probably ‘hey, you’!
women teachers can be a bit precious. Even today ( maybe American Way or even Renee can assist), I can’t tell you in American terms the difference between Miss and Ma’am, except the latter seems prevalent in some parts, but not all over the South.