Flight lieutenant in the context of "Captain (British Army and Royal Marines)"

The title flight officer was a military rank used by the United States Army Air Forces during World War II, and also an air force rank in several Commonwealth countries, where it was used for female officers and was equivalent to the rank of flight lieutenant. The term flight officer is sometimes used today to describe job title positions as aircrew members.

Squadron leader (Sqn Ldr or S/L) is a senior officer rank used by some air forces, with origins from the Royal Air Force. The rank is used by air forces of many countries that have historical British influence.

Squadron leader is immediately senior to flight lieutenant and immediately below wing commander. It is usually equivalent to the rank of lieutenant commander in the navy and of the rank of major in other services.