All military and naval personnel are addressed in official correspondence by their full titles. Off duty in conversations and in unofficial correspondence, officers are addressed as follows: ARMY, AIR FORCE, MARINE CORPS All general officers General Colonels and Lt. Colonels Colonel Majors Major Captains Captain Lieutenants Mister or Lieutenant Lieutenants in Medical Corps Doctor or Lieutenant All Chaplains Chaplain Army nurses Nurse Cadets (Official address) Cadet (Unofficial address) Mister Warrant Officers Mister All sergeants Sergeant Corporals Corporal Privates and Privates, First Class Private Jones or Jones When the name is not known, an Army private may be addressed as "Soldier," and in the Marine Corps the term, "Marine," is proper in such a case. NAVY, COAST GUARD All Admirals Admiral Commodores Commodore Captains Captain Commanders Commander Lieutenant Commanders, lieutenants, ensigns and midshipmen Mister All Chaplains Chaplain All medical officers (to commander) Doctor Except when in the presence of troops, senior officers frequently address juniors as "Smith" or "Jones" but this does not give the junior the privilege of addressing the senior in any other way than his proper title. By the same token, officers of the same grade generally address one another by their first or last names depending on the degree of intimacy. The courtesy and respect for others which govern the conduct of gentlemen are expected to prevail at all times.