In the United States Army, the term “MOS” stands for “Military Occupational Specialty”. It’s a code used to identify a specific job. The MOS 00 is not a specific job code. However, there are some codes that start with 00 which have specific meanings. For example, MOS 00F is an identifier for MOS Immaterial for the position, which means that any MOS with the required grade can fill it1. Another example is MOS 00Z, which identifies positions and personnel in grade E9 (CSM & SGM) where the incumbents are Sergeants Major of organizations commanded by General Officers2.