Officer Candidate

Common military ranks in English
Navies	Armies	Air forces
Commissioned and Non-commissioned officers
Admiral of the fleet	Marshal or Field marshal	Marshal of the air force
Admiral	General	Air chief marshal
Vice admiral	Lieutenant general	Air marshal
Rear admiral	Major general	Air vice-marshal
Commodore	Brigadier or Brigadier general	Air commodore
Captain	Colonel	Group captain
Commander	Lieutenant colonel	Wing commander
Lieutenant commander	Major or Commandant	Squadron leader
Lieutenant	Captain	Flight lieutenant
Sub-lieutenant	Lieutenant or First lieutenant	Flying officer
Ensign	Second lieutenant	Pilot officer
Midshipman	Officer cadet	Flight cadet
Enlisted grades
Warrant officer or Chief petty officer	Warrant officer or Sergeant major	Warrant officer
Petty officer	Sergeant	Sergeant
Leading seaman	Corporal	Corporal
Seaman	Private	Aircraftman

Officer candidate or Officer aspirant (OA) is a rank in some militaries of the world that is an appointed position while a person is in training to become an officer. More often than not, an officer candidate was a civilian who applied to join the military directly as an officer. Officer candidates are, therefore, not considered of the same status as enlisted personnel.

In several NATO countries, the term Officer designate (OF-D) is used. In the NATO rank scale, it comes below the grade of OF-1 and above the grade of Student Officer. Ranks designated as OF-D include dokimos efedros axiomatikos in the Hellenic Army, and chuẩn úy ("officer designate") in the Vietnam People's Army. In the German Armed Forces, officer designates are enlisted personnel and have a corresponding rank code.

In the Finnish Defence Forces, officer candidate is an NCO rank, comparable to sergeant. Usually officer candidates are chosen as conscripts, and along with officer cadets are promoted to the rank of second lieutenant.

In the German Armed Forces, officer designates are enlisted personnel. Soldiers accepted for officer training are given the annotation (OA) for Offizieranwärter ("Officer Aspirant") to their rank. Then the designate progresses through the ranks of Fahnenjunker (OR-5), Fähnrich (OR-6) and Oberfähnrich (OR-7) in the German Army and german Air Force. Officer designates in the German Navy go through the corresponding ranks of Seekadett, Fähnrich zur See and Oberfähnrich zur See instead.

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Wikipedia