<P> The United States Marine Corps Military Occupational Specialty (MOS) is a system of categorizing career fields . All enlisted and officer Marines are assigned a four digit code denoting their Primary occupational field and specialty . Additional MOSs may be assigned through a combination of training and / or experience, which may or may not include completion of a formal school and assignment of a formal school code . </P> <P> Occupational Fields (OccFlds) are identified in the first two digits and represents a grouping of related MOSs . Job codes are identified in the last two digits and represent a specific job within that OccFld . </P>

What does mos mean in the marine corps
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