| After The Flat | Accounts and Finance |
| Ambato | Airport Code |
| Australian Temporary Fencing | Business |
| Aviation Turbine Fuel | Business |
| As Trustee For | Business |
| Bureau of Alcohol, Tobacco, and Firearms (former name) | Business |
| After The Future | Business |
| American Type Foundry | Business |
| American Type Founders | Business |
| Activating Transcription Factor | Business |
| Albuquerque Teachers Federation | Community |
| ASEAN Tourism Forum | Community |
| All Things Forgotten | Community |
| American Taekwondo Foundation | Community |
| All Time Favorite | Community |
| Accreditation Task Force | Community |
| Features Working Group (TC AT) | Computer and Networking |
| Administrative Task Force | Computer and Networking |
| Adobe Transfer Functions | Computing |
| Application Transparent Failover | Computing |
| Automatic Tracking Following | Computing |
| Autoload Overlay Trace Formatter | Computing |
| Architecture Task Force | Computing |
| Ascii Text Format | Computing |
| Adobe Type Font | Computing |
| Advanced Title Format | Computing |
| Application Transport Failover | Computing |
| Area To Free | Computing |
| French Southern Territories | Country ISO Code |
| Automation Test Facility | Electronics |
| Accident Tolerant Fuel | General |
| Automatic Transmission Fluids | General |
| Alcohol Testing Form | General |
| Authorised Testing Facility | General |
| Automated Test Facility | General |
| Automotive Trades Foundation | General |
| Automotive and Tractor Faculty | General |
| Automotive Technology Fair | General |
| Automotive Task Force | General |
| Fleet Tug (Auxiliary, Tug, Fleet) | General |
| Automated Testing Framework | General |
| Ajax Tools Framework | General |
| Accelerator Test Facility | General |
| Allschutz Transport Fahrzeug | General |
| All The F | General |
| All Things Fresh | General |
| and ATF definition | General |
| Always Think Forfeiture | General |
| Alcohol Tobacco and Firearms | General |
| AGI Task Force | General |
| Advanced Thin Films | General |
| Authoring Tools Framework | General |
| Authorised Treatment Facility | General |
| American Typecasting Fellowship | General |
| Addicted To Fresh | General |
| Above The Fold | General |
| Always Totally Foolish | General |
| Advanced Tactical Fighters | General |
| Average Transaction Frequency | General |
| Authorised Treatment Facilities | General |
| Alcohol Tobacco Firearms | General |
| Amino Terminal Fragment | General |
| All Terrain Flotation | General |
| After the flood | General |
| Alaskan Thunder F*** | General |
| Analog To Future | General |
| Animal Task Force | General |
| Aerodrome Traffic Frequency | General |
| All Time Finest | General |
| Across The Fence | General |
| Almost The Fbi | General |
| Airport Transport Forum | General |
| Agreement on Trade Facilitation | General |
| Anti-Terrorist Financing | Governmental |
| Alochol Tobbaco and Firearms | Governmental |
| Anti Terrorism Force | Governmental |
| Automatic Transmission Fluid | Governmental |
| Austrian Task Force | Governmental |
| Automatic Transmission Ford | Governmental |
| After The Fire | Governmental |
| Allied Tactical Force | Governmental |
| A** To the Floor | Internet |
| Anterior Talofibular | Medical |
| Amphibious Task Force | Military and Defence |
| Bureau of Alcohol, Tobacco, Firearms, and Explosives | Military and Defence |
| Alliance Task Force | Military and Defence |
| Acquire The Fire | Military and Defence |
| Advanced Tactical Fighter | Military and Defence |
| Air Task Force | Military and Defence |
| All Try Fire | Military and Defence |
| Advanced Targeting Flir (forward Looking Infrared) | Military and Defence |
| Asian Tennis Federation | Sports |
