Joint Regulation 4120.15E: Designating and Naming Military Aerospace Vehicles is the current system for designating all aircraft, helicopters, rockets, missiles, spacecraft, and other aerial vehicles in military use by the United States Armed Forces. History United States Department of Defense Directive 4120.15 "Designating and Naming Military Aircraft, Rockets, and Guided Missiles" was originally issued November 24, 1971 and named the Air Force as the Executive Agent empowered to carry out the directive. Directive 4120.15 was implemented by Air Force Regulation (AFR) 82-1/Army Regulation (AR) 70-50/Naval Material Command Instruction (NAVMATINST) 8800.4A on March 27, 1974. The Joint Regulation designation system was heavily based upon the 1962 US Tri-Service aircraft designation system but also took control of the previously separate designation system for missiles and drones. The current version was enacted by Joint Regulation 4120.15E Designating and Naming Military Aerospace Vehicles and was implemented via Air Force Instruction (AFI) 16-401, Army Regulation (AR) 70-50, Naval Air Systems Command Instruction (NAVAIRINST) 13100.16 November 3, 2020. The list of US military aircraft was kept via 4120.15-L Model Designation of Military Aerospace Vehicles 31 August 2018 until its transition to data.af.mil. Overview There are two basic components to a craft's identity: its vehicle designation and its popular name. A vehicle designation is sometimes referred to as a Mission Design Series (MDS), referring to the three main parts of the designation that combine to form a unique profile for each vehicle. The first letters (up to four) signify the type of craft and its mission. The design number, preceded by a dash "-", essentially signifies the product design of the aircraft (i.e. design 16 in F-16A). The series number identifies the specific "production model of a particular design number" with subsequent series indicating major revisions or changes. Finally, there may be variant and block identifiers which clarify the exact configuration of the vehicle. The popular name is a matter of less specific construction, but is aimed at providing an official common name which eases identification and communication regarding the vehicle. The popular name is not used in official internal publications (an official internal report would refer to the "F-16" and "AIM-9" but not mention the names "Fighting Falcon" or "Sidewinder"). The popular name may be based on the manufacturer's internal name for the craft but all popular names must have the manufacturer's permission and be approved by the DoD. Pilots often have their own nicknames for