List of Acronyms and Initialisms: A - AR

AR

• ar – (s) Arabic language (ISO 639-1 code)
• Ar – (s) Argon
• AR – (s) Argentina (FIPS 10-4 country code; ISO 3166 digram) – Arkansas (postal symbol) – Armour – (s) Arunachal Pradesh (Indian state code)
• ara – (s) Arabic language (ISO 639-2 code)
• ARAG – (a) Advanced Research and Assessment Group
• ARB – (i) Administrative Review Board
• ARBA – (a/i) Army Review Boards Agency
• ARC – (i) Arc-second Raster Chart – Appalachian Regional Commission
• ARCA – (a) Automobile Racing Club of America
• ARCENT – (p) United States Army Central Command
• ARDA – (a) Advanced Research and Development Activity (became DTO 2006)
• ARE – (i) UK Admiralty Research Establishment (–1991) – (s) United Arab Emirates (ISO 3166 trigram)
• ARF – (i) ASEAN Regional Forum
• arg – (s) Aragonese language (ISO 639-2 code)
• ARG – (s) Argentina (ISO 3166 trigram)
• ARH – (s) Armed Reconnaissance Helicopter
• ARI – (i) Acute Respiratory Infection – U.S. Army Research Institute for the Behavioral and Social Sciences
• ARL – (i) UK Admiralty Research Laboratory (1921–1977) – U.S. Army Research Laboratory – UIUC Aviation Research Laboratory
• ARM – (a) Anti-Radiation Missile – Adjustable-rate mortgage – (s) Armenia (ISO 3166 trigram)
• ARNet – (p) Acquisition Reform Network
• ARP – (i) Address Resolution Protocol – Applied Research Programme
• ARPA – (a) Advanced Research Projects Agency
• ARRC – (i) ACE Rapid Reaction Corps
• ARRF – (i) Allied Rapid Reaction Force
• ARRL -
• ARS – (i) Agricultural Research Service – (s) Argentine peso (ISO 4217 currency code)
• ARSC – (i) Arctic Region Supercomputing Center
• ARSPACE – (p) U.S. Army Space Command
• ART – (a) Adaptive Resonance Theory – Anti-Retroviral Therapy
• ARTCC – (i) Air Route Traffic Control Center
• ARWG – (i) Army Research Working Group ("are-wig")