Non - commissioned officer A non - commissioned officer ( sometimes spelled noncommissioned officer , abbreviated to NCO or non - com ( US ) ) , called a sub - officer in some countries , is a military officer who has not been given a commission . Non - commissioned officers , in the English - speaking world , usually obtain their position of authority by promotion through the enlisted rank s . The NCO corps usually includes all grades of corporal and sergeant ; in some countries , warrant officer s also carry out the duties of NCOs . The naval equivalent includes some or all grades of petty officer , although not all navies class their petty officers as NCOs . There are different classes of non - commissioned officer , including junior non - commissioned officers ( JNCO ) and senior ( or staff ) non - commissioned officers ( SNCO ) . Function . The non - commissioned officer corps is often referred to as " the backbone " of the armed services , as they are the primary and most visible leaders for most military personnel . Additionally , they are the leaders primarily responsible for executing a military organization ' s mission and for training military personnel so they are prepared to execute their missions . NCO training and education typically includes leadership and management as well as service - specific and combat training . Senior NCOs are considered the primary link between enlisted personnel and the commissioned officer s in a military organization . Their advice and guidance is particularly important for junior officers , who begin their careers in a position of authority but generally lack practical experience . National usage . An experienced NCO corps is a key component of Western armies . Australia . In the Australian Army , the NCOs perform most of the physical duties and management . Lance corporals and corporals are called junior NCOs , while sergeants , staff sergeants , warrant officers class two and one are classified as senior NCOs . Officers in the Australian Army perform paper work duties whilst in a barracks environment while the NCOs ensure discipline is being maintained . In battle , it is the senior NCOs that ensure the soldiers are doing their job , while the officers are looking at the wider tactical picture . In the New South Wales Police Force , NCOs perform supervisory and coordination roles . The ranks of probationary constable through to leading senior constable are referred to as " constables " . All NCOs within the NSW Police are given a warrant of appointment under the Commissioner ' s hand and seal . All officers within the Australian Defence Force Cadets are non - commissioned . ADFC officers are appointed by the Director - General of their respective branch . Canada . In the Canadian Forces , the Queen ' s Regulations and Orders formally defined a non - commissioned officer as " A Canadian Forces member holding the rank of Sergeant or Corporal . " In the 1990s , the term " non - commissioned member " ( NCM ) was introduced to indicate all ranks in the Canadian Forces from recruit to chief warrant officer . By definition , with the unification of the CF into one service , the rank of sergeant included the naval rank of petty officer 2nd class , and corporal includes the naval rank of leading seaman ; Corporal also includes the appointment of master corporal ( naval master seaman ) . NCOs are officially divided into two categories : junior non - commissioned officers , consisting of corporals / leading seamen and master corporals / master seamen ; and senior non - commissioned members , consisting of sergeants and petty officers 2nd class . In the Royal Canadian Navy , however , the accepted definition of " NCO " reflects the international use of the term ( i . e . all grades of petty officer ) . Junior Non - commissioned officers mess and billet with privates and seamen ; their mess is usually referred to as the junior ranks mess . Conversely , senior non - commissioned officers mess and billet with warrant officers ; their mess is normally referred to as the warrant officers and sergeants mess ( army and air force establishments ) or the chiefs and petty officers mess ( naval establishments ) . As a group , NCOs rank above privates and below warrant officers . The term " non - commissioned members " includes these ranks . Finland . In the Finnish Defence Force , NCO ' s ( Aliupseeristo ) includes all ranks from corporal ( " alikersantti " , lit . sub - sergeant ) to sergeant major ( " sotilasmestari " , lit . soldiermaster ) . Ranks of lance corporal ( " korpraali " ) and leading seaman ( " ylimatruusi " ) are considered not to be NCO ranks . This ruling applies to all branches of service and also to the troops of the Border Guard . Sweden . In 1983 the NCO corps , since 1972 called the " Platoon Officer Corps " , was disbanded and its members were given commissions as officers in ranks of second or first lieutenant in Sweden ' s new one - tier military leadership system . In 2009 a similar system as the NCO corps was re - established , called " specialist officers " . Direct recruitment from civilian life is followed by basic and preparatory leadership training , and advanced leadership training during 1 . 5 year as a specialist cadet at the military academy in Halmstad , a warrant as an OR - 6 , followed by specialist technical training . Swedish specialist officers have relative ranks that matches the commissioned officers ; an OR - 7 takes precedent over a second lieutenant , for instance . France . In France and French - speaking countries like Belgium and most former French colonies , the term " sous - officier " ( meaning : " lower officer " or " sub - officer " ) is a class of ranks between the rank - and - file ( " hommes du rang " ) and commissioned officers ( " officiers " ) . Corporals ( " caporal " and " caporal - chef " ) belong to the rank - and - file . Sous - officiers include two subclasses : " subalternes " ( sergents and sergents - chefs ) and " supérieurs " ( adjudants , adjudants - chefs and majors ) . " Sous - officiers supérieurs " can perform various functions within a regiment or battalion , including commanding a platoon or section . Germany . In Germany and German - speaking countries like Austria , the term " Unteroffizier " ( meaning : " lower officer " or " sub - officer " ) describes a class of ranks between normal enlisted personnel ( " Mannschaften " or in Austria " Chargen " ) and officers ( " Offiziere " ) . In this group of ranks there are , in Germany , two other classes : " Unteroffiziere mit Portepee " ( with sword - knot ) and " Unteroffiziere ohne Portepee " ( without swordknot ) , both containing several ranks , which in Austria would be " Unteroffiziere " ( NCOs ) and " Höhere Unteroffiziere " ( senior NCOs ) . New Zealand . In the New Zealand Defence Force , a non - commissioned officer is defined as : Singapore . In the Singapore Armed Forces , the term " non - commissioned officer " is no longer officially used , being replaced with Specialist . The term NCO however is still frequently used unofficially among the army . United Kingdom . In the British Armed Forces , NCOs are divided into two categories . lance corporal s ( lance bombardier , depending on unit ) and corporals ( lance sergeant , bombardier , lance corporal of horse ) are junior NCOs . Sergeants ( corporal of horse , sergeant ) and staff sergeant s ( colour sergeant and staff corporal ) ( and in the RAF chief technician s and flight sergeant s ) are senior NCOs . Warrant officers are often included in the senior NCO category , but actually form a separate class of their own , similar in many ways to NCOs but with a royal warrant . Senior NCOs and WOs have their own messes , which are similar to officers ' messes ( and are usually known as sergeants ' messes ) , whereas junior NCOs live and eat with the unranked personnel . The Royal Navy does not refer to its petty officers as NCOs , but calls them senior ratings ( or senior rates ) . Leading rating s and below are junior ratings . United States . In the United States Army , United States Air Force , and United States Marine Corps , all ranks of sergeant are termed NCOs , as are corporals in the Army and Marine Corps . A Marine Corps lance corporal is not considered an NCO . The rank of corporal ( E - 4 ) in the Army is a junior NCO , and is to be shown the same respect as any other NCO . In the United States Navy and United States Coast Guard , all ranks of petty officer are so designated . Junior NCOs ( E - 4 through E - 5 grade ) , or simply " NCOs " ( E - 4 and E - 5 only ) in USMC usage , function as first - tier supervisors and technical leaders . NCOs serving in the top three enlisted grades ( E - 7 , E - 8 , and E - 9 ) are termed senior non - commissioned officers ( chief petty officers in the Navy and Coast Guard ) . Senior NCOs are expected to exercise leadership at a more general level . They lead larger groups of service members , mentor junior officers , and advise senior officers on matters pertaining to their areas of responsibility . A select few senior NCOs in paygrade E - 9 serve as Senior Enlisted Advisor s to senior commanders in each service ( e . g . , major command , fleet , force , etc . ) and in DoD ( unified commands , e . g . , STRATCOM , EUCOM , PACOM , etc . , and DoD agencies , e . g . , DISA , DIA and NSA . One senior E - 9 , selected by the service chief of staff , is the ranking NCO / PO in that service , holds the highest enlisted rank for that service , and is responsible for advising their service secretary and chief of staff . One E - 9 holds a similar position as the SEA to the Chairman of the Joint Chiefs of Staff . Senior enlisted advisors , service enlisted advisors and the SEA to the Chairman advise senior officer and civilian leaders on all issues affecting operational missions and the readiness , utilization , morale , technical and professional development , and quality of life of the enlisted force . Within the United States Marine Corps , senior NCOs are referred to as staff noncommissioned officers and also include the rank of staff sergeant ( E - 6 ) . SNCOs are those career marines serving in grades E - 6 through E - 9 . The ranks include staff sergeant , gunnery sergeant ( E - 7 ) , master sergeant / first sergeant ( E - 8 ) , and master gunnery sergeant / sergeant major ( E - 9 ) . Unlike warrant officers in other militaries , warrant officers in the United States Armed Forces are considered specialty officers and fall between non - commissioned and commissioned officers . Warrant officers also have their own rank tier and paygrade . However , when warrant officers achieve the rank of chief warrant officer ( CWO2 ) or higher , they are commissioned and are considered commissioned officers just like any other commissioned officer , but are still held in a different paygrade tier . They are entitled to salutes from their juniors , an officer ' s saber and uniform , but for much of the Uniform Code of Military Justice ( UCMJ ) are considered on par with NCOs . NCO Candidate Course . Beginning in 1967 at Fort Benning , Georgia , the US Army Non - commissioned Officer Candidate Course ( NCOOC ) was a Vietnam - war era program developed to alleviate shortages of enlisted leaders at squad and platoon level assignments , training enlisted personnel to assume jobs as squad leaders in combat . Based loosely on the Officer Candidate School ( OCS ) , NCOC was a new concept ( at the time ) where high performing trainees attending basic infantry combat training were nominated to attend a 2 - phased course of focused instruction on jungle warfare , and included a hands - on portion of intense training , promotion to sergeant , and then a 12 - week assignment leading trainees going through advanced training . Regular Army soldiers who had received their promotion through traditional methods ( and others ) used derisive terms for these draftees ( typically ) who were promoted quicker , such as " Instant NCOs , Shake ' n ' Bake and ' Whip n ' Chills . ' The program proved to be so successful that as the war began to wind down they elected to institutionalize training non - commissioned officers and created the NCO Education System ( NCOES ) , which was based around the NCO Candidate Course . NCO Candidate course generally ended in May 1971 .