Markmanship Instructor
The manual took effect on May 15, 2006, but personnel implementation was explicitly deferred. No specific effective date is given for the 8531-to-0931 change, so 2006 identifies the manual transition rather than an exact conversion date.
Source extraction notes
The cited source prints the MOS code but not its occupational title; no title was inferred. Enlisted MOS moved to new occupational field 09, Training. The manual is effective 2006-05-15, but personnel/HRDP implementation is explicitly deferred, so effective_to is null. No row-specific effective date is printed; year-only precision reflects the 2006 manual transition.
Source documents (2)
Reviewed September 24, 2026 against references 1, 2 and 3.
- MARADMIN 329/06, MOS Manual Changes and Conversions
1. MARADMIN 329/06, paragraph 1.B(5), enlisted block, lines 152-154 · source dated July 20, 2006 · cited by the explanation
Open source document (opens in a new tab)3.MARADMIN 329/06, MOS Manual Changes and Conversions · event transcription · docs/legacy-data/usmc-mos-conversions.jsonl:106; MARADMIN 329/06, paragraph 1.B(5), enlisted block, lines 152-154 · cited by the explanation
Open source document (opens in a new tab) - MCO P1200.16, Military Occupational Specialties Manual, 18 Apr 2005 (title source)
2. Figure 3-37, alphabetical listing of enlisted MOSs, printed p. 3-521 / PDF p. 712, MOS 8531 title row · cited by the explanation
PDF page 712 (opens in a new tab)