| tec | TECkit Compiled Mapping Table |
| tei | TrackEye Image Sequence Data |
| tek | Tektronix HEX Data |
| teq | TINA Equation File |
| ter | Terragen Terrain File |
| terrain | Terragen Terrain File |
| tet | Textease Database CT Single-user Database Template |
| tew | Bentley InRoads Text Export Wizard Data |
| texter | Texter Snippet Data |
| tfa | TreeSoft CashFlow Analysis Data |
| tfam | PLINK Individual Information File |
| tfd | Tape Format Requirements Document |
| tfh | Borland Turbo Profiler Help Data |
| tfl | Tific Client Data |
| tfv | YETI Vegetation Plot Database Export File |
| tfx | Avid Pro Tools Eleven Rack Presets |
| tfz | FBS Vehicle Database |
| tgc | Terragen Clip File |
| tgd | Terragen 2 World |
| tgf | libigl Control Handle Graphs |
| tgl | SkyMap Target Lists |
| tgmd | WDTV ThumbGen Movie Metadata |
| tgo | Terragen Object File |
| tgs | GSTree Tree Data |
| tgw | Terragen World |
| th | Therion Data |
| th2 | Therion TH2 Map |
| tha | Thunderbird MoreFunctionsForAddressBook Add-on Data |
| the | Microsoft Plus! Theme File |
| theme | Microsoft Windows Desktop Theme |
