ACP 125 is the short name for Allied Communications Publication 125: Communications Instructions—Radiotelephone Procedures, developed and published by the Combined Communications Electronics Board, for use by the Five Eyes nations and the rest of NATO. According to the latest version, The standard defines the procedures for communicating by voice over two-way radio, and has served as the basis for radio communications procedures for many non-military organizations, as well as numerous U.S. government organizations, including the United States Department of State and the Civil Air Patrol.