The Predator system was initially designated the RQ-1 Predator. The "R" is the United States Department of Defense designation for reconnaissance and the "Q" refers to an unmanned aircraft system. The "1" describes it as being the first of a series of aircraft systems built for unmanned reconnaissance. Pre-production systems were designated as RQ-1A, while the RQ-1B (not to be confused with the Predator B, which became the MQ-9 Reaper) denotes the baseline production configuration. These are designations of the "system" as a unit. The actual aircraft themselves were designated RQ-1K for pre-production models, and RQ-1L for production models. In 2002, the USAF officially changed the designation to MQ-1 ("M" for multi-role) to reflect its growing use as an armed aircraft.