Chapter 3, Part B of the Joint Travel Regulations (JTR), titled “Training Travel,” establishes the comprehensive guidelines and travel allowances for Department of Defense personnel attending instructional courses and educational events. The regulation dictates the critical temporal threshold for active-duty Service members, classifying courses with a scheduled duration of 139 or fewer days as Temporary Duty (TDY), while those lasting 140 or more days are designated as a Permanent Change of Station (PCS). It provides detailed allowance frameworks for diverse groups, including Reserve Component (RC) members attending Active Duty for Training (ADT) or Inactive Duty Training (IDT)—with specific compensation rules based on whether they commute daily or travel outside ...