The United States Coast Guard's ratings are general occupations that consist of specific skills and abilities. Each rating has its own specialty badge, which is typically worn on the left sleeve of their service dress uniform by enlisted personnel in that particular field. On operational dress uniforms, they wear generic rate designators that exclude the rating symbol. Commissioned officers do not have ratings. U.S. Coast Guard ratings are the equivalent of the rating system used by the United States Navy, known as Navy Enlistment Classification (NEC) codes. The United States Army and United States Marine Corps use Military Occupational Specialty (MOS) codes and the United States Air Force use Air Force Specialty Codes (AFSC) that service the same function as U.S. Coast Guard and U.S. Navy