Chapters 3 and 5 and sections 402–407, 409–411, and 414 of this title apply equally to persons who are not serving as members of a uniformed service but whose pay or allowances, or both, are assimilated under law or a regulation prescribed under law, to the pay or allowances, or both, of commissioned officers, warrant officers, or enlisted members of any grade, rank, or rating in any uniformed service.