| Rank | Abbreviation | Meaning |
|---|
| ***** | ASTT | Angle Sum Triangle Theorem
| |
| ***** | ASTT | Aeronautics and Space Transportation Technology
| |
| ***** | ASTT | Australasian Society for Trenchless Technology
| |
| ***** | ASTT | Association Sportive de Tennis de Table
| |
| ***** | ASTT | Advisory Service on Transfer of Technology
| |
| ***** | ASTT | Active Sustained Transfer Technology
| |
| ***** | ASTT | Agricultural Society of Trinidad and Tobago
| |
| **** | ASTT | Auto Start Twin Timer
| |
| **** | ASTT | Airborne Surveillance and Tracking Technology
| |
| **** | ASTT | Advocates for Survivors of Trauma and Torture
| |
| **** | ASTT | Autistic Society of Trinidad & Tobago
| |
| **** | ASTT | American Society of Traffic and Transportation
| |
| **** | ASTT | Air Sample Tracking/Trending
| |
| **** | ASTT | Aeronautices and Space Transportation Technology
| |
| **** | ASTT | Applied Science Technologists and Technicians
| |
| **** | ASTT | Association for Trenchless Technology
| |
| **** | ASTT | American Society for Trenchless Technology
| |
| *** | ASTT | Advanced Space Transportation Technologies
| |
| *** | ASTT | Anti Submarine Torpedo Tube
| |
| ** | ASTT | Apollo Special Task Team
| |
| ** | ASTT | Advanced Surveillance Tracking Technology
| |
| ** | ASTT | Adjustable Spam Threshold Tuning
| |
| ** | ASTT | Action Speed Tactics Trainer
| |
| ** | ASTT | Action Speed Tactical Trainer
| |
| ** | ASTT | Advanced Simulation Technology Thrust
| |