Warrant Officer

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

A warrant officer (WO) is an officer in a military organisation who is designated an officer by a warrant, as distinguished from a commissioned officer who is designated an officer by a commission, and a non-commissioned officer who is designated an officer, often by virtue of seniority.

The rank was first used in the 13th century in the (then) English Royal Navy and is today used in most services in many countries, including the Commonwealth nations and the United States.

Outside the United States, warrant officers are included in the "Other Ranks" (OR) category, equivalent to the US "E" (Enlisted) category and rank between non-commissioned officers and commissioned officers. The warrant officers in Commonwealth navies rank between chief petty officer and sub-lieutenant, in Commonwealth air forces between flight sergeant and pilot officer, and in Commonwealth armies between staff sergeant and second-lieutenant.

Warrant officers in the United States are classified as officers and are in the "W" category (NATO "WO"); they are technical leaders and specialists. Chief warrant officers are commissioned by the President of the United States and take the same oath as regular commissioned officers. They may be technical experts with a long service as enlisted personnel, or direct entrants, notably for U.S. Army helicopter pilots.

The warrant officer corps began in the nascent English Royal Navy. At that time, noblemen with military experience took command of the new Navy, adopting the military ranks of lieutenant and captain. These officers often had no knowledge of life on board a ship—let alone how to navigate such a vessel—and relied on the expertise of the ship's master and other seamen who tended to the technical aspects of running the ship. As cannon came into use, the officers also required gunnery experts; specialist gunners began to appear in the 16th century and also had warrant officer status. Literacy was one thing that most warrant officers had in common, and this distinguished them from the common seamen: according to the Admiralty regulations, "no person shall be appointed to any station in which he is to have charge of stores, unless he can read and write, and is sufficiently skilled in arithmetic to keep an account of them correctly". Since all warrant officers had responsibility for stores, this was enough to debar the illiterate.

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Wikipedia