Although German and Italian aircraft were not given code names by their Allied opponents, in 1942, Captain Frank T. McCoy, an intelligence officer of the USAAF, invented a system for the identification of Japanese military aircraft. Initially using short, "hillbilly" boys' names such as "Pete", "Jake", and "Rufe", the system was later extended to include girls' names and names of trees and birds, and became widely used by the Allies throughout the Pacific theater of war. This type of naming scheme differs from the other use of code names in that it does not have to be kept secret, but is a means of identification where the official nomenclature is unknown or uncertain.