Military Occupational Specialty
code used in the U.S. Army and Marine Corps to identify a specific job
Military Occupational Specialty (MOS) refers to the position earned/assigned to someone in the U.S. Armed Forces. These MOS's consist of letters and numbers, each of which signifies your position, duties, and job within the armed services. For example, the MOS for a Army Combat Engineer is 12B. They provide their expertise in areas such as mobility, countermobility, survivability and general engineering. They also are responsible for helping tackle rough terrain in combat areas. Aka, they blow stuff up when it's in the way of something trying to move past it. There's a ton of different MOS's and someone will eventually put them in here.
