United States Signals Intelligence System
Department of Defense Regulation 5240.1-R, Procedures Governing the Activities of DOD Intelligence Components that Affect U.S. Persons, § C188.8.131.52 (Dec. 1982): “United States Signals Intelligence System”
United States Signals Intelligence System means the unified organization for signals intelligence activities under the direction of the Director, National Security Agency/Chief, Central Security Service, comprised of the National Security Agency, the Central Security Service, the components of the Military Services authorized to conduct signals intelligence and such other entities (other than the Federal Bureau of Investigation) as are authorized by the National Security Council or the Secretary of Defense to conduct signals intelligence. FBI activities are governed by procedures promulgated by the Attorney General.