| tp_webwiz | ThumbsPlus Web Scheme Data |
| tq | STK Torque File |
| tq5 | TQSL Certificate Request Data |
| tq6 | TQSL Certificate Data |
| tq8 | TQSL Signed Certificate Data |
| tqc | TqcRunas Document |
| tqi | Parasoft Insure++ Interface Data |
| tqq | Ten Quick Questions Data |
| tqr | EROS B Metadata |
| tqs | Parasoft Insure++ Data |
| tqsl | TQSL Log |
| tqx | NZ Infoshare Table Query File |
| tqz | TurningPoint QuestionPoint Data File |
| tr | CIRS Transaction Data |
| tr0 | SPICE Transient Analysis Output Data |
| tr1 | SPICE Transient Analysis Output Data |
| tr1 | IBM VoiceType Data File |
| tr2 | SPICE Transient Analysis Output Data |
| tr3 | SPICE Transient Analysis Output Data |
| tr4 | SPICE Transient Analysis Output Data |
| tr5 | OnyxTree Professional Data |
| tr5 | SPICE Transient Analysis Output Data |
| tr6 | SPICE Transient Analysis Output Data |
| tr7 | SPICE Transient Analysis Output Data |
| tr8 | SPICE Transient Analysis Output Data |
| tr9 | SPICE Transient Analysis Output Data |
| tra | WinTrack Railroad Track |
| tra | RFM Transmission Spectrum File |
| trace | VMware ThinApp Binary Trace Log |
| trak | NI Traktor Pak File |
| trashinfo | Linux Trash Storage Metadata |
| traw | PLINK Variant-major Additive Component File |
| trb | HP Printer Diagnostic Package |
| trbw | STAR-CCM+ TurboWizard File |
| trc | Lattice Reveal Analyzer Waveform Data |