Billet requirements identified by a MOS (BMOS) must include a training concept when established that builds an inventory of Marines prepared for assignment to the BMOS.Separate MOSs are not appropriate based on grade changes unless merging with other MOSs. A single track is limited to a single MOS.

MOSs not meeting this criterion will be deemed as nonperforming MOSs and subject to deletion/disapproval.

MOSs must serve a Human Resources Development Process (HRDP) purpose (establish a skill requirement, manpower planning, manages the forces, manage training, identify special pay billets).

MOSs with no Table of Organization (T/O) requirement or no inventory are subject to deletion/disapproval.

MOSs must be required in sufficient numbers as Billet MOSs (BMOS) in the Total Force Structure Manpower System (TFSMS) to be justified.

Non-PMOSs will not be associated in current service records with General Officers and Colonels, with the exception of MOSs 822X/824X Foreign Area Officers and Regional Affairs Officers.

Colonels are considered fully qualified Marine Air Ground Task Force (MAGTF) Officers and, with the exception of lawyers and MOSs 8059/61 Acquisition Management Professionals, will only hold MOSs 8040, 8041, or 8042 as PMOS.

Restricted officers (limited duty officers and warrant officers) cannot hold non-primary MOSs and will be limited to Primary MOS (PMOS) – Basic MOS (BMOS) matches.

Not all instances of the word or word-part 'man' were removed, e.g., 0171 Manpower Information Systems (MIS) Analyst, 0311 Rifleman, 0341 Mortarman. On 30 June 2016, the Marine Corps announced the renaming of 19 MOSs with gender-neutral job titles, replacing the word or word-part 'man' with the word 'Marine' in most. Previous versions of MCO 1200.17_ series directives are cancelled, including MCO 1200.17E, the last in the series before beginning the annual NAVMC-type directive series. The USMC now publishes an annual Navy/Marine Corps joint publication (NAVMC) directive in the 1200 Standard Subject Identification Code (SSIC) series to capture changes to the MOS system. Job codes are identified in the last two digits and represent a specific job within that OccFld. Occupational Fields (OccFlds) are identified in the first two digits and represents a grouping of related MOSs. 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. All enlisted and officer Marines are assigned a four-digit code denoting their primary occupational field and specialty. The United States Marine Corps Military Occupational Specialty ( MOS) is a system of categorizing career fields.

Marine corps mos job descriptions