U.S. Army Combat Arms Regimental System in the context of "Individual Ready Reserve"

The Individual Ready Reserve (IRR) is a category of the Ready Reserve of the Reserve Component of the Armed Forces of the United States composed of former active duty or reserve military personnel. Its governing statute is codified at 10 U.S.C. § 10144. For soldiers in the National Guard of the United States, its counterpart is the Inactive National Guard (ING). As of 22 June 2004, the IRR had approximately 112,000 members (does not include all service IRR populations) composed of enlisted personnel and officers, with more than 200 Military Occupational Specialties are represented, including combat arms, combat support, and combat service support.