The 'captain' group
These nouns are used to address someone with a particular job or rank in a fairly formal way. They are often spelled with a capital letter.
bishop brother captain colonel commander comrade constable count countess detective doctor father general inspector lieutenant major minister nurse officer prime minister professor sergeant sergeant major sister vicar
You can tell your men to prepare to move out, Captain.
I've no idea, Inspector.
I've been sick again, nurse.