Speaking as a former O-3 myself, I just state that fact once, and let it be done. It becomes apparent in so many other ways: my rapier wit, my professional bearing, my limitless depth of knowledge, my utter modesty, ...
Besides, it smacks of, "Did you know I was an officer?"
Standard response: I COULD have been an officer, but my parents were married.....
UsVets Dictionary
Captain (kap-tan)1) Rank between Modified civilian (1Lt) and Junior Officer (Major). 2) The guy who almost never pees on his hands. 3) Individual most likely to ask the Supply Sgt for a box of grid squares.
Sure, but how many of your kids are officers?