I am positive all branches of the service have similar ratings. Few veterans would forget theirs. Hell, I even remember my serial number.
Serial Number....What years were you in?
When I was in it was just your SS#. No more serial numbers. It was too many numbers for the Army types to remember!
I was making a point about the semantics, among other things. My AFSC was 2T451 - General Purpose Vehicle Mechanic Craftsman.
Marine Corps uses specialty, as in MOS, military occupational specialty (IIRC). No "rating" or proficiency. 0311 is a grunt, 0811 a cannon cocker, etc.