Second Lieutenant (United States)

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

Second lieutenant (called under-lieutenant in some countries) is a junior commissioned officer military rank in many armed forces.

Like the United Kingdom, the rank of second lieutenant replaced the rank of ensign and cornet in 1871. The rank of second lieutenant was phased out in the Australian Regular Army in 1986.

The Canadian Forces adopted the rank with insignia of a single gold ring around the service dress uniform cuff for both army and air personnel upon unification in 1968 until the late 2000s. For a time, naval personnel used this rank but reverted to the Royal Canadian Navy rank of acting sub-lieutenant, though the CF green uniform was retained until the mid-1980s. Currently, the Canadian Army insignia for second lieutenant is a pip and the Royal Canadian Air Force insignia for lieutenant is one thick braid. The equivalent rank for the Royal Canadian Navy is acting sub-lieutenant. Also known as an Ensign in the Foot Guards units. (Canadian Grenadier Guards & Governor General's Foot Guards )

The insignia consists of a metal-colored bar in accordance with the color of the ceremonial uniform buttons and hat's symbol.

For example, for the infantry, gold being the metal of the ceremonial dress' buttons, the symbol on the képi being a golden grenade with two crossed rifles, therefore the Sous-Lieutenant's insignia is a gold-colored bar.

For cavalry or forest rangers (light infantry mobilised from the Water and Forests Corp), ceremonial dress' buttons were silver, as was the hunting horn on the forest commissioned officer's képi, therefore the Sous-Lieutenant's insignia is a silver-colored bar.

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Wikipedia