22 SAS normally has a strength of 400 to 600. The regiment has four operational squadrons: A, B, D and G. Each squadron consists of approximately 65 men commanded by a major, divided into four troops (each troop being commanded by a captain) and a small headquarters section. Troops usually consist of 16 men (Members of the SAS are variously known as "blade" or "Operator") and each patrol within a troop consists of four men, with each man possessing a particular skill e.g. signals, demolition, medic or linguist in addition to basic skills learned during the course of his training. The term "squadron" dates back to the unit's earliest days when the unit's name was intended to confuse German intelligence. The four troops specialise in four different areas: