Warrant Officer A Warrant Officer ( WO ) is an officer in a military organization who is designated an officer by a warrant , as distinguished from a commissioned officer who is designated an officer by a commission , or non - commissioned officer ( NCO ) who is designated an officer by virtue of seniority . The rank was first used in the ( then ) English Royal Navy and is today used in many other countries , including the Commonwealth nations , the United States and Ireland . Outside the United States they are effectively senior non - commissioned officers with long military experience , although technically in a cadre of their own between NCOs and commissioned officers . However , warrant offices in the United States are technical leaders and specialists , and 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 long service or direct entrants , notably for U . S . Army helicopter pilots . History : Origins in the Royal Navy . The warrant officer corps began in the 13th century 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 . Four categories of WOs . Originally , warrant officers were specialist professionals whose expertise and authority demanded formal recognition . They eventually developed into four categories : Literacy was one thing that all 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 . Demise of the Royal Naval warrants . In 1843 , the wardroom warrant officers were given commissioned status , while in 1853 the lower - grade warrant officers were absorbed into the new rate of Chief Petty Officer , both classes thereby ceasing to be warrant officers . By the time of the First World War , the standing warrant officers had been divided into two grades : Warrant Officers and Chief Warrant Officers ( or " Commissioned Warrant Officers " , a phrase that was replaced in 1920 with " Commissioned Officers from Warrant Rank " , although they were still usually referred to as " Commissioned Warrant Officers " , even in official documents ) . Their ranks had by then expanded with the adoption of modern technology in the Navy to include Telegraphist s , Electricians , Shipwright s , Artificer Engineers , etc . Both WOs and CWOs messed in the Warrant Officers ' mess rather than the wardroom ( although in ships too small to have a WOs ' mess they did mess in the wardroom ) . WOs and CWOs carried swords , were saluted by ratings , and ranked between Sub - Lieutenant s and Midshipmen . In 1949 , the ranks of WO and CWO were changed to " Commissioned Officer " and " Senior Commissioned Officer " , the latter ranking with but after the rank of Lieutenant , and they were admitted to the wardroom , the WOs messes closing down . Collectively these officers were known as " Branch Officers " , being retitled " Special Duties " officers in 1956 . In 1998 , the Special Duties list was merged with the General list of officers in the Royal Navy , all officers now having the same opportunity to reach the highest commissioned ranks . Modern Usage . Australia . The Australian Army has three Warrant Officer ranks . The most senior Warrant Officer rank is that of Warrant Officer ( WO ) , introduced in 1991 . This rank is held by the Regimental Sergeant Major of the Army ( RSM - A ) . It is the most senior non - commissioned rank in the Australian Army and is held by only one person at a time . The insignia are a crown for a WO2 , the Australian coat of arms ( changed from the royal coat of arms in 1976 ) for a WO1 , and the Australian coat of arms surrounded by a wreath for the RSM - A . The Royal Australian Navy has two Warrant Officer ranks , Warrant Officer of the Navy and Warrant Officer . Singapore . In the Singapore Armed Forces , Warrant Officers are former Specialists who have attained the rank of Master Sergeant and have been selected for and graduated from the " Joint Warrant Officer Course " at SAF Warrant Officer School . Warrant officers rank between Specialists and commissioned officers . They ordinarily serve as Battalion , Brigade , etc . Regimental Sergeant Major s . A great deal of them serve as instructors and subject - matter experts in various training establishments . Warrant officers are also seen on the various staffs headed by the respective manpower , intelligence , etc . officers . There are five grades of warrant officer . Warrant Officers usually have their own mess . For smaller units , this mess may be combined with the Officers ' Mess as the Officers ' / Warrant Officers ' Mess . Warrant Officers wear their insignia on their epaulettes like officers , instead of on the sleeve like specialists and other soldiers . This signifies that Warrant Officers often have similar responsibilities to commissioned officers . Warrant Officers are addressed as " Sir " by those junior to them or by " Warrant ( Surname ) " . They are also commonly addressed " Encik " ( " Mister " ) by commissioned officers . They are not , however , saluted by enlisted ranks . United Kingdom . Royal Navy . In 1973 , warrant officers reappeared in the Royal Navy , but these appointments followed the Army model , with the new warrant officers being ratings rather than officers . They were initially known as Fleet Chief Petty Officer s ( FCPOs ) , but were renamed Warrant Officers in the 1980s . They always ranked with Warrant Officers Class I in the British Army and Royal Marines and with Warrant Officers in the Royal Air Force . British Army . In the British Army , there are two warrant ranks , Warrant Officer Class 2 ( WO2 ) and Warrant Officer Class 1 ( WO1 ) , the latter being the senior of the two . It used to be more common to refer to these ranks as WOII and WOI ( using Roman instead of Arabic numerals ) . Warrant Officer 1st Class or 2nd Class is incorrect . The rank immediately below WO2 is Staff Sergeant ( or Colour Sergeant ) . Royal Marines . Before 1879 , the Royal Marines had no warrant officers : by the end of 1881 , the Royal Marines had given warrant rank to their sergeants - major and some other senior NCOs , in a similar fashion to the Army . When the Army introduced the ranks of Warrant Officer Class I and Class II in 1915 , the Royal Marines did the same shortly after . From February 1920 , Royal Marines Warrant Officer Class Is were given the same status as Royal Navy Warrant Officers and the rank of Warrant Officer Class II was abolished in the Royal Marines , with no further promotions to this rank . The Marines had introduced warrant officers equivalent in status to the Royal Navy ' s from 1910 with the Royal Marines Gunner ( originally titled Gunnery Sergeant - Major ) , equivalent to the Navy ' s warrant rank of Gunner . Development of these ranks closedly paralleled that of their naval counterparts : as in the RN , by the Second World War there were Warrant Officers and Commissioned Warrant Officers , e . g . Staff Sergeant Major s , Commissioned Staff Sergeant Majors , Royal Marines Gunners , Commissioned Royal Marines Gunners , etc . As officers they were saluted by junior ranks in the Royal Marines and the Army . These all became ( commissioned ) Branch officer ranks in 1949 , and Special Duties officer ranks in 1956 . United States . In the United States military , a Warrant Officer ( grade W - 1 to W - 5 ) is ranked as an officer above the senior - most enlisted ranks , as well as officer cadets and candidates , but below the officer grade of O - 1 ( " NATO : OF - 1 " ) . Warrant officers are highly skilled , single - track specialty officers , and while the ranks are authorized by Congress , each branch of the Uniformed Services selects , manages , and utilizes warrant officers in slightly different ways . For appointment to Warrant Officer One ( W - 1 ) , a warrant is approved by the secretary of the respective service . " Chief Warrant Officers " ( W - 2 to W - 5 ) are commissioned by the President of the United States and take the same oath as regular commissioned officers ( O - 1 to O - 10 ) . Warrant officers can and do command detachments , unit s , activities , vessels , aircraft , and armored vehicles as well as lead , coach , train , and counsel subordinates . However , the Warrant Officer ' s primary task as a leader is to serve as a technical expert , providing valuable skills , guidance , and expertise to commanders and organizations in their particular field .