Chief warrant officer Chief Warrant Officer is a military rank used by the Canadian Forces , the Israel Defense Forces , the South African National Defence Force and since 2012 , the Singapore Armed Forces . Canada . In the Canadian Forces , a Chief Warrant Officer or CWO is the most senior non - commissioned member ( NCM ) rank in the Canadian Army and the Royal Canadian Air Force . Its equivalent rank in the Royal Canadian Navy is Chief Petty Officer 1st Class ( CPO1 ) . A CWO is senior to the rank of Master Warrant Officer ( MWO ) and its Royal Canadian Navy equivalent of Chief Petty Officer 2nd Class ( CPO2 ) . Cadets Canada uses the ranks of Chief Petty Officer 1st Class , Chief Warrant Officer , and Warrant Officer 1st Class respectively . This organization ' s uniforms use a similar Coat of Arms insignia as the Canadian Forces . The French language form is " adjudant - chef " " ( adjuc ) " . Insignia . The rank insignia of the CWO is similar to the Coat of Arms of Canada , worn on both forearms of the Service Dress tunic ; in gold metal and green enamel miniature pins on the collar of the Service Dress shirt and outerwear coats ( Army only ) ; on CADPAT slip - ons worn in the middle of the chest , embroidered in tan ( Army ) or blue ( Air Force ) thread ; and in gold thread on blue slip - ons on both shoulders of other uniforms ( Air Force only ) . For whatever reason , the Canadian Forces did not update the CWO / CPO1 insignia to reflect the 1985 changes to the Coat of Arms of Canada , specifically the addition of an annulus behind the shield bearing the motto of the Order of Canada . ( This would make the insignia technically incorrect . ) Forms of address . CWOs are generally initially addressed as " Chief Warrant Officer " , and thereafter as " Sir " or " Ma ' am " by subordinates ; and as Mr . or Ms . by commissioned officers . If they hold the appointment of Regimental Sergeant - Major , they may also be addressed as " RSM " by the Commanding Officer . CWOs are never addressed as " Chief " , this being a form of addressed reserved for Chief Petty Officer s . Civilians can address them as Chief Warrant Officer or CWO or as Mr . or Ms . Appointments . CWOs may hold a number of appointments , some of which are listed below : Special appointments or Senior Appointments for Chief Warrant Officers and Chief Petty Officers 1st Class entitle the incumbents to wear a modified rank badge or an addition to the rank badge . They are as follows : Due to the unified nature of the Canadian Forces , it is not unheard - of for Royal Canadian Air Force CWOs or even Royal Canadian Navy CPO1s – especially those of the so - called " purple trades " , such as logistics or military police – to find themselves filling the appointment of RSM in what are otherwise considered Canadian Army units ( such as Service Battalions or Communication Regiments ) . Conversely , it is not impossible for a Canadian Army CWO or Royal Canadian Navy CPO1 to find themselves as the Squadron CWO of a Royal Canadian Air Force squadron . Messes and quarters . CWOs generally mess and billet with other Warrant Officer s and with Sergeant s , and their Royal Canadian Navy equivalents , Chief Petty Officer s and Petty Officer s . Their mess on military bases or installations are generally named the " Warrant Officers and Sergeants Mess " . Uniforms . Although NCMs , CWOs generally wear the uniform accoutrements of commissioned officers ; for example , officer cap badge , waistcoat instead of cummerbund with mess kit , Sam Browne belt instead of sash for infantry , etc . Israel Defense Forces . The רב - נגד Rav nagad , a " Chief Warrant Officer " is the most senior non - commissioned officers rank in the Israel Defense Forces ( IDF ) . Because the IDF is an integrated force , they have a unique rank structure . IDF ranks are the same in all services ( army , navy , air force , etc . ) . The ranks are derived from those of the paramilitary Haganah developed in the British Mandate of Palestine period to protect the Yishuv . This origin is reflected in the slightly - compacted IDF rank structure . South Africa . In 2008 the Warrant Officer ranks of the South African National Defence Force were expanded and the rank of Chief Warrant Officer was created . In the South African Navy a Chief Warrant Officer is the senior NCO in Fleet Command . In the South African Army the equivalent is the senior NCO in an Army Formation , such as Armour , Infantry etc .