Does addressing a member of the military a certain way indicate formality of an event? I asked a friend what his formal title is. He told me CPT and said, "I wasn't planning on wearing blues, but I can if you want. I was just going to wear a suit." I said of course a suit is fine; the event itself isn't that formal, I just wanted the formal way to address him.
I think using CPT rather than Mr. is the appropriate way to address someone at that rank regardless of event formality, but I figured I better check so that I'm not indicating that the event is black tie or anything like that. Also, is it offensive if I just use Mr. or Ms./Mrs. for people in the military?