Some sailors and Coast Guardsmen receive a rating following completion of a military technical training course for that particular rating known as an "A" school. Other sailors and Coast Guardsmen who have completed the requirements to be assigned a rating and have been accepted by the Navy Personnel Command/Bureau of Naval Personnel (USN) or the Coast Guard Personnel Service Center Command (USCG) as holding that rating (a process called "striking") are called "designated strikers", and are referred to by their full rate and rating in formal communications (i.e., machinist's mate fireman (MMFN), as opposed to simply fireman (FN)), though the rating is often left off in informal communications. Those who have not officially been assigned to a rating are officially referred to as "undesignated" or "non-rates." Once selected for a particular rating of their choice they become eligible for advancement in that community.