Warrant officer is a category of specialized officers in the US military. They exist in the Army, Navy, Marine Corps and Coast Guard; the last Air Force warrant officer retired in 1992 (the program had been discontinued in 1959).

The title of "warrant officer" dates back as far as the 1300's when the British Navy was run primarily by royalty. The noble families gave themselves titles on ships but were often not trained in operating any aspect of the boat. They issued "royal warrants" to experienced and knowledgeable sailors who were then put between the officers and crewmen in the power structure of the ship.

The first warrant officer positions in the US military were established after conflict between military personnel and civilian mine-laying specialists demonstrated an inability to work together in World War I. The Army Warrant Officer Corps was established July 9, 1918.

Generalized officers, often called commissioned officers, form the bulk of the leadership structure in the armed forces. These are the lieutenants, majors, colonels and generals you see on TV news and in the movies. Men and women, a majority of whom hold college degrees1, who make decisions and lead units. Warrant officers, on the other hand, are specialized officers. They are recruited (often from exemplary noncommissioned officers) with a single task in mind and work in that field for their entire (remaining) career in the military. Typical roles include technicians and pilots.

New Army and Marine Corps warrant officers, after completing training, are assigned pay grade W1. After about two years, these specialists are promoted to W2, and are receive a commission from the President and have similar level of authority to their commissioned counterparts. Navy warrant officers enter at the W2 level. The warrant officer ranks go up to W5, Chief Warrant Officer 5 (except in the Navy, where they peak at CWO4), and typically require 5-6 years of service between promotions.

Depending on the level of formality, warrant officers are addressed as: Chief (Army) or Gunner (Marine Corps); Mr. or Ms.; Warrant Officer or Chief Warrant Officer (formal).

Oh, and enlisted personnel have to salute them.

1. For those who have been told all officers have bachelor's degrees or higher, this is mostly true. There are some paths for those who are exceptional enlistedpersons to be promoted to officer ranks. The best example of this is the Limited Duty Officer in the Navy, but there are examples in the other services as well. Stats on this, direct from the DOD, can be found at http://www.defenselink.mil/pubs/almanac/almanac/people/military_education_stats.html