| NSA | National Security Agency Fort Meade, http://www.nsa.gov |
| CSA | Cyber Security Agency, EU |
| SARPA | Security Advanced Research Projects Agency |
| NIMA | National Imaging and Mapping Agency |
| NSC | National Security Council Washington, DC, http://www.whitehouse.gov/nsc |
| NCSC | National Computer Security Center |
| NCSA | National Computer Security Association |
| NCSC | National Computer/Computing Security Center |
| NASDAQ | National Association of Security Dealers Automated Quotations ein automatisches Kursnotierungssystem für Wertpapiere |
| RA | Radiocommunications Agency |
| LEA | Law Enforcement Agency |
| EDA | European Defence Agency Brüssel, http://www.eda.europa.eu |
| EPA | Environmental Protection Agency Washington, DC, http://www.epa.gov |
| CIA | Central Intelligence Agency |
| CNA | Central News Agency |
| MCA | Medicine Control Agency medizinische Aufsichtsbehörde Großbritanniens |
| REA | Rail Express Agency |
| IEA | International Energy Agency Paris, http://www.iea.org |
| DLA | Defense Logistics Agency |
| E.N.A. | European news agency Brüssel, http://www.european-news-agency.com |
| DEA | Drug Enforcement Agency |
| JMA | Japan Meteorological Agency |
| UTA | United Talent Agency |
| DCA | Defense Communications Agency |
| FEMA | Federal Emergency Management Agency Washington, DC, http://www.fema.gov |
| JANA | Jamahiriya News Agency [engl.] Libysche Nachrichtenagentur |
| FIAT | Field Intelligence Agency Technical |
| EUREKA | European Reasearch Coordination Agency Agentur für europäische Forschungskoordination |
| AID | Agency for International Development [engl.] |
| JEIA | Joint Export-Import-Agency |
| DISA | Defense Information System Agency |
| ERFA | European Radio Frequency Agency vgl. Brüssel, [BE], http://www.nato.int |
| AEA | Austrian Energy Agency [engl.] Österreichischen Energieagentur ,Wien |
| ECDA | European Cycle Development Agency |
| APA | Austrian Press Agency [engl.] Wien, http://www.apa.co.at |
| USIA | United States Information Agency |
| IAEA | International Atomic Energy Agency Internationale Atomenergie Organisation [IAEO] |
| DARPA | Defense Advanced Research Projects Agency |
| CEPMA | Central European Pipeline Management Agency |
| DIA | Defence Intelligence Agency [Pentagon-Abteilung] Washington, D.C., http://www.dia.mil |
| CCTA | Central Computer and Telecommunication Agency [engl.] Britisches IT-Unternehmen, heute OGC |
| ARPA | Advanced Research Projects Agency [engl.] Forschungsinstitut des amerikanischen Verteidigungsministeriums |
| USEPA | United States Environmental Protection Agency |
| AHRQ | Agency for Healthcare Research and Quality [engl.] Agentur für die Gesundheitsfürsorge-Forschung und Qualität |
| ASSA | Austrian Solar and Space Agency [engl.] Österreichische Gesellschaft für Sonnenenergie und Weltraum |
| ADRA | Adventist Development and Relief Agency [engl.] Adventistische Entwicklungs- und Katastrophenhilfe e.V., Weiterstadt |
| ACCT | Agency Council on Coordinated Transportation [engl.] Olympia, [WA], http://www.wsdot.wa.gov/acct/ |
| ARPAnet | Advanced Research Projects Agency Network [engl.] Vorläufer vom Internet |
| AHCPR | Agency for Health Care Policy Research, jetzt AHRQ |
| SAS | Security Association |