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Marine Corps · SSN history

500 Trainee, Branch Immaterial

Appendix B suggests SSN 521 for the earlier SSN 500 title “Trainee, Branch Immaterial,” subject to review of the individual's Qualification Card against the job specifications. The asterisk ties that suggestion to the earlier title, not to “Military Specialty Undetermined,” which was the title listed for SSN 500 in both June 1944 and June 1945.

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Codes named in this history

Codes without a directory match

  • 521 stated by the source. No directory or archive record matches.

Documented history

Trainee, Branch Immaterial

June 1945 is the manual's publication date. No effective date for this suggested reclassification is stated.

  • SSN 521 was a suggested reclassification, not an automatic conversion or proof that an individual was reclassified.
Source extraction notes

Predecessor title from the AR 615-26 column: Trainee, Branch Immaterial. Suggested conversions/remarks, as printed: *521. Asterisks bind the suggestions to the correspondingly marked earlier title, not to an unmarked present-title meaning. The Present Title column is the manual's June 1945 meaning: Military Specialty Undetermined. It is not a present-day MOS equivalence. These are suggested reclassifications subject to individual Qualification Card and job-specification review, not automatic or present-day equivalents. The table gives no row-level calendar effective date. June 1945 is the manual publication date, not an inferred individual conversion date.

Source documents (1)

Reviewed September 24, 2026 against references 3 and 4.

Historical information is drawn from the sources linked above. Classification dates are not personal service dates. Spot an error? Let us know.