The reference establish the system used to publish all training standards, provide policy, and assign training responsibilities, especially as applied to the System Approach to Training (SAT). ITS establish training standards for all Marines in the same occupation field (OccFld), Military Occupational Specialty (MOS), or billet. They provide a foundation upon which unit commanders, Functional Learning Center (FLC) directors, and distance learning (DL) developers build training packages for individual Marines as part of unit training plans or formal courses of instruction. ITSs represent the skills that contribute to the unit mission as expresses in the Mission Performance Standards (MPS).