| Activity Relationship Chart | Academic & Science |
| Automated Radiotheodolite | Academic & Science |
| Architectural Resources Cambridge | Academic & Science |
| Academic Resource Connection | Academic & Science |
| Architecture Registration Corps | Academic & Science |
| Academic Resource Center | Academic & Science |
| Aftercare Research Counselling | Academic & Science |
| Academic Regulations Committee | Academic & Science |
| Australian Research Council | Academic & Science |
| Applied Research Center | Academic & Science |
| Academic Research Collaborative | Academic & Science |
| Artifact Research Centre | Academic & Science |
| Area Research Center | Academic & Science |
| Academy of Richmond County | Academic & Science |
| Artificial intelligence, Robotics & Consciousness | Academic & Science |
| Aviation Research Centre | Academic & Science |
| Architecture Restoration Conservation | Academic & Science |
| Advanced Reader Copy | Academic & Science |
| Archaeological Resource Centre | Academic & Science |
| Accreditation and Registration Council | Academic & Science |
| Allison Road Classroom | Academic & Science |
| Autonomous Robotic Controller | Academic & Science |
| Accurate Radius Curvature | Academic & Science |
| Astrophysical Research Consortium | Academic & Science |
| Agulhas Return Current | Academic & Science |
| Accounting Regulatory Committee | Accounts and Finance |
| Arctic Village (ak) | Airport Code |
| Abortion Rights Campaign | Associations & Organizations |
| Airport Regions Council | Associations & Organizations |
| African Rainforest Conservancy | Associations & Organizations |
| Alliance of Religions and Conservation | Associations & Organizations |
| Australian Red Cross | Associations & Organizations |
| Augmentation Research Center | Associations & Organizations |
| Aircraft Radio Corpoation | Business |
| American Record Corporation | Business |
| Arena Racing Company | Business |
| Auto Research Center | Business |
| Access Rescue Canada | Business |
| Atlantic Richfield Company | Business |
| Acknex Resource Center | Business |
| Attentive Reliable Courteous | Business |
| American Restoration Contractors | Business |
| Airlines Reporting Corporation | Business |
| Agricultural Risk Consultants | Business |
| Area Residence Coordinator | Business |
| American Record Company | Business |
| American Reprographics Company | Business |
| Amalgamated Roadstone Corporation | Business |
| Account Receivables Conversion | Business |
| Authorised Release Certificate | Business |
| Aluminum Rigid Conduit | Business |
| Advice and Reformation Committee | Business |
| Asset Reconstruction Company | Business |
| Arcontech Group, P.L.C. | Business |
| Artists Residents Chicago | Community |
| Autism Resource Centre | Community |
| Association for Retarded Citizens | Community |
| Association for Retarded Children | Community |
| Awareness, Responsibility, and Communication | Community |
| Association of Retarded Citizens | Community |
| Animal Rights Conference | Community |
| Adoption Resource Center | Community |
| Advocacy, Respect, and Community | Community |
| Allied Rainbow Communities | Community |
| Activity and Recreation Center | Community |
| Association of Related Churches | Community |
| American Refugee Committee | Community |
| Anteater Recreation Center | Community |
| Albino Rabbit Club | Community |
| Annual Report Card | Community |
| Accessing Resources For Community | Community |
| Apiit Recreational Club | Community |
| Affinity, Reality, Communication | Community |
| Animal Rescue Center | Community |
| Audio Return Channel | Community |
| Activity Recreation Center | Community |
| Art Response And Copy | Community |
| Advocacy for Respect for Cyclists | Community |
| Advanced Readers Copy | Community |
| Area Recreation Center | Community |
| Architectural Review Committee | Community |
| Action, Reflection, and Celebration | Community |
| Alarm Reporting Control | Computer and Networking |
| ARChive | Computing |
| Atomically Reference Counted | Computing |
| Argonaut Risc Core | Computing |
| Authenticated Request Code | Computing |
| Automatic Relay Computer | Computing |
| Attack Retrieve Capture | Computing |
| Automatic Reference Counting | Computing |
| Attached Resources Computing | Computing |
| Aspect Ratio Control | Computing |
| Archive File | Computing |
| Area Chart | Computing |
| Access Rights Class | Computing |
| Action Replay Codes | Computing |
| Aspect Ratio Convert | Computing |
| Atm Research Consortium | Computing |
| Architecture Resource Center | Computing |
| Archival Research Catalog | Computing |
| Audio Response Controller | Computing |
| Automated Reference Counting | Computing |
| Almaden Research Center | Computing |
| Antivirus Research Center | Computing |
| Authenticated Received Chain | Computing |
| ArcadeNetwork | Cryptocurrency |
| Arcade | Cryptocurrency |
| ARCx (old) | Cryptocurrency |
| American River College | Educational Institute |
| Anti-reflective Coating | Electronics |
| Arc Or Pkarc Compressed File Archive | File Type |
| Automated Assistance in Roadworks and Congestion | General |
| Alcohol Racing Components | General |
| American Racer Cup | General |
| Atelier Recherche Creation | General |
| Association of Riley Clubs | General |
| Automobile Recycling Congress | General |
| Alfa Romeo Control | General |
| African Rally Championship | General |
| Auto Retro Club | General |
| Auto Restoration Club | General |
| Amg Red Cut | General |
| Amg Ride Control | General |
| American Racing Club | General |
| Alerte Risque Collision | General |
| Automotive Repair Center | General |
| Auto Refinishing Centre | General |
| Automotive Recruitment Consultants | General |
| Audi Renting Class | General |
| Additional Remote Control | General |
| Automotive Resource Center | General |
| Aries Custom | General |
| Automotive Restoration Club | General |
| Australian Rally Commission | General |
| Accelerating Rate Calorimetry | General |
| Absorb Reflect Counter | General |
| Agriculture Risk Coverage | General |
| Automatic Ride Control | General |
| Active Roll Control | General |
| Accident Research Centre | General |
| Australian Rally Championship | General |
| Automotive Research Center | General |
| Accident Repair Centre | General |
| Approved Repair Centre | General |
| Automotive Recyclers of Canada | General |
| Alfa Romeo Club | General |
| Adaptive Robust Control | General |
| Adaptive Ride Control | General |
| Advanced Research for Chariots | General |
| Active Ride Control | General |
| Aussie Racing Cars | General |
| American Refugee Commitee | General |
| Automatic Retarder Control | General |
| Action Reinhard Camps | General |
| Airport Reference Code | General |
| Aimee And Ralph Cabrera | General |
| Advanced Reciprocating Cannula | General |
| Advance Reading Copy | General |
| Accounts Receivable Conversion | General |
| Art Rhythm And Combination | General |
| Advanced Rope Control | General |
| Aktion Reinhard Camps | General |
| Air Rifle Club | General |
| Advanced Reading Copy | General |
| Airworthiness Review Certificate | General |
| Art Renewal Center | General |
| Address Resolution Client | General |
| Advance Reader Copy | General |
| App Runtime | General |
| App Runtime for Chrome | General |
| Advocacy Resource CenterHow | General |
| Advanced Reconnaissance Clone | General |
| All Round Craft | General |
| Art For Real Change | General |
| Cable Repair Ship (Auxiliary, Repair, Cable) | General |
| Advanced Recon Commando | General |
| Advocacy Resource Center | General |
| Accreditation Review Commission | General |
| Automatic Reception Control | General |
| Avatar Rendering Cost | General |
| Anti Recidivism Coalition | General |
| Alternative Radio Coalition | General |
| Anime Realm Cosplay | General |
| Acid Rocket Clan | General |
| Advanced Risc Console | General |
| Alliance of Rutherford County | Governmental |
| Appalachian Regional Commission | Governmental |
| Awareness Responsibility Communication | Governmental |
| Appalachian Regional Committee | Governmental |
| Abject Reform Confinement | Governmental |
| Alcohol Recovery Center | Governmental |
| Addicts Rehabilitation Center | Governmental |
| Actual Rolling Conditions | Governmental |
| Auckland Regional Council | Governmental |
| Advanced Recycling Center | Governmental |
| Armada Nacional de Colombia | Governmental |
| Army Reuse Center | Governmental |
| Agricultural Resource Center | Governmental |
| Airline Reporting Corporation | Governmental |
| Alien Residents Card | Governmental |
| Action Reinhardt Camps | Governmental |
| Alien Resident Certificate | Governmental |
| Allison Road Center | Governmental |
| Aviation Royale Canadienne | Governmental |
| Agricultural Research Council | Governmental |
| Administrative Reforms Commission | Governmental |
| Alien Registration Card | Governmental |
| Alberta Research Council | Governmental |
| American Red Cross | Healthcare |
| Adaptive Replacement Cache | Information Technology |
| Advanced RISC Computing | Information Technology |
| Avions Ren Couzinet | International |
| Actually Real Crush | Internet |
| Acquire Retain and Cultivate | Jobs |
| Augmented Renal Clearance | Medical |
| Activity-Regulated Cytoskeleton | Medical |
| AIDS Related Complex | Medical |
| Accessible, Responsive, and Caring | Medical |
| Australian Resuscitation Council | Medical |
| Aerobic Respiration Control | Medical |
| Arthritis Research Campaign | Medical |
| Access Respite Care | Medical |
| Aggregation of Red Cells | Medical |
| Absolute Reticulocyte Count | Medical |
| Accreditation Review Committee | Medical |
| Accreditation Review Council | Medical |
| Addiction Research Center | Medical |
| Age-Related Cataract | Medical |
| Ageing Research Centre | Medical |
| AIDS-related condition | Medical |
| Annual Rate of Change | Medical |
| Annual Report on Carcinogens | Medical |
| Antigen Responsive Cell | Medical |
| Application Review Committee | Medical |
| Ashcroft Rehabilitation Center | Medical |
| Arthritis and Rheumatism Council | Medical |
| Abnormal Retinal Correspondence | Medical |
| Arthritis Rehabilitation Center | Medical |
| Atypical Reparative Changes | Medical |
| Allergic RhinoConjunctivitis | Medical |
| Attack, Retrieve, and Capture | Military and Defence |
| Airborne Radio Communications | Military and Defence |
| Advanced Reconnaissance Commando | Military and Defence |
| Army Recruiting Command | Military and Defence |
| Almost Ready To Cover | Military and Defence |
| Advanced Research Center | Military and Defence |
| Advanced Rotor Concepts | Military and Defence |
| Accounting Requirements Code | Military and Defence |
| Arc Second Raster Chart | Military and Defence |
| Air Reserve Component | Military and Defence |
| Attitude, Respect, Cooperation | Military and Defence |
| Architecture Review Committee | Military and Defence |
| Advanced Router Configuration | Networking |
| Advanced Resource Connector | Networking |
| Archaeological Review from Cambridge | News & Entertainment |
| Amateur Radio Club | Radio Science |
| Advance Radio Car | Radio Science |
| Arctic Village Airport, Arctic Village, Alaska USA | Regional |
| Aramaic | Regional |
| Alexander Railroad Company | Regional |
| Atlanta Regional Commission | Regional |
| Austin Regional Clinic | Regional |
| Arctic | Regional |
| ARChive of Contemporary Music | Regional |
| Artist-Run Centre | Regional |
| Alexander Railroad | Regional |
| African Risk Capacity | Regional |
| Ames Research Center | Space Science |
| Association of Rover Clubs | Sports |
| Arcane Roleplayers Consortium | Sports |
| American Roundball Corporation | Sports |
| Alloy Racing Composites | Sports |
| Adventure Racing Canada | Sports |
| Atlantic Rally for Cruisers | Sports |
| Active Race Control | Sports |
| Athletics–Recreation Center | Sports & Games |
| American Rivers Conference | Sports & Games |
| Americas Rugby Championship | Sports & Games |
| Australian Rugby Championship | Sports & Games |
| Alphense Racing Club | Sports & Games |
| Adelaide Rowing Club | Sports & Games |
| Atlanta Rowing Club | Sports & Games |
| Auction Rate Securities Certificate | Stock Exchange |
| Access to the Region’s Core | Transport & Travel |
| Arctic Village Airport | Transport & Travel |
| Anaheim Rapid Connection | Transport & Travel |
| Aqaba Railway Corporation | Transport & Travel |
