A Canadian armoured regiment (and most Commonwealth regiments), such as the King's Own Calgary Regiment, is made up of several tank squadrons. Each squadron is commanded by an officer of the rank of Major whom is know as the OC. However, as anyone who has been in the Army knows, a squadron may be commanded by the OC, but it is run by the senior non-commissioned officer, in this case the Squadron Sergeant Major. The SSM is in charge of the squadron's rear echelon, which is responsible for supporting the squadron's forward combat troops. This entails providing the troops with food, ammunition, fuel and other such supplies essential to the efficient operation of a tank squadron.