Different airlines and different cultures used different phrases. My favourite was Lufthansa -their response was to call the Captain by his christian name.
Said it before ... as a fairly new Nav-S/O on the crew commanded by one of the "older" WWII bomber pilots that we nicknamed the North Atantic Barons, I addressed the co-pilot by his christian name. The Captain swung around and announced in his best Parade Ground voice - "we do NOT use christian names on the flight deck MR xxxxxx "
CRM wasn't even a gleam in anyones' eye at that stage, Sir was God.
A psychiatrist died and went to heaven, St. Peter met him at the Pearly Gates, and said " Glad you've come, we're having a little trouble with God, he thinks he's a BOAC Captain "