the five branches of the u.s. armed forces all use the same "e-" designation for enlisted pay grades, with service-specific names applied to each (e.g., chief petty officer, master gunnery sergeant, private first class). each branch incorporates it as part of a service member's job specialty designator. in the united states air force, this job specialty designator is known as an air force specialty code, in the united states army and united states marine corps, a military occupational specialty, and in the united states navy and united states coast guard, a rating.