Lieutenant (Lt) (pronounced Lef-tenant) is a junior officer rank of the British Army and Royal Marines. It ranks above second lieutenant and below captain and has a NATO ranking code of OF-1 and it is the senior subaltern rank. Unlike some armed forces which use first lieutenant, the British rank is simply lieutenant, with no ordinal attached. The rank is equivalent to that of a flying officer in the Royal Air Force. Although formerly considered senior to a Royal Navy sub-lieutenant, the Army and Navy ranks of lieutenant and sub-lieutenant are now considered to be of equivalent status. The Army rank of lieutenant has always been junior to the Navy's rank of lieutenant. In the 21st-century British Army, the rank is ordinarily held for up to three years. A typical appointment for a lieutenant might be the command of a platoon or troop of approximately thirty soldiers.