| trk | STAR-CD v4 Droplet Track Data |
| trk | Train Dispatcher Data |
| trl | Holux GM-101 Tracklog |
| trl | Topocad Roadlines Data |
| trm | eSignal Trade Manager Data |
| trm | Oracle Trace Map Data |
| trm8 | Avantes Avasoft v8 Transmittance Mode Data |
| trn | CFX Transient File |
| trn | Corel Quattro Pro Translation Support Data |
| trn | MegaHAL Training Data |
| trn | Microsoft SQL Server Transaction Log |
| trn | Oracle Documaker Transaction Data |
| trn | PTC Creo Turning Parameter Data |
| trn | STN Express Transcript Text |
| trn | TextBridge Pro Trainging Data |
| tro | IBM Voice Type Data |
| trp | MotionTracking Track Search Parameters Data |
| trp | Topocad Road Profile |
| trp | TrimeTool TRP Output |
| trp | TripMaker Document |
| trr | GROMACS Trajectory File |
| trs | Table Retrieval System Document |
| trs | TrIDNet Serialized Definitions Package |
| trs | WinTrack Railroad Track Text Data |
| trt | Team Sports Scheduling System Report Template |
| truck | Rigs of Rods Truck Description File |
| trv | Topocad Traverse Document |
| trxml | Textkernel Sourcebox XML Data |
| try | CIBSE Test Reference Year Data |
| trz | Norton Antivirus Rapid Release Definition Update |
