Demystifying the 4 Main CRSC Categories (video) By: Joel Pettit • February 19, 2024 Joel Pettit – private PEB attorney, and former JAG and government FPEB appellate attorney – explains the 4 most popular categories in Combat Related Special Compensation (CRSC): Instrumentalities of War, Hazardous Service, Armed Combat, and Simulation of War. Joel discusses the nuances that plague each category and the reasons why military retirees get confused when trying to decided which category or categories their medical condition(s) fall under.