• Rating – Identifies broad enlisted career fields (occupational specialties) that encompass related aptitude, training, experience, knowledge, and skills for the purpose of career development and advancement.
• NEC (Navy Enlisted Classification) – NEC codes supplement the enlisted rating structure in identifying personnel on active or inactive duty and billets in manpower authorizations. NEC codes identify a non-rating wide skill, knowledge, aptitude, or qualification that must be documented to identify both people and billets for management purposes. The NEC coding system facilitates management control over enlisted skills by identifying billets and personnel and enhancing efficient use of personnel in distribution and detailing.

• DESIG (Designator) – Identifies primary specialty qualifications, associated legal and specialty categories and competitive categories for promotion.
• NOBC (Navy Officer Billet Classification) – Functionally describes general occupational duties. 
• SSP (Subspecialty) – Identifies postgraduate education (or equivalent training and/or experience) in various fields and disciplines.
• AQD (Additional Qualification Designation) – Identifies additional qualifications and skills not included in the other code structures.

Links and References

NEOCS Process Chart