| tei | TrackEye Image Sequence Data |
| tei | Text Encoding and Interchange Data |
| tek | Tektronix HEX Data |
| teo | TruTops Tube Data |
| teq | TINA Equation File |
| ter | Terragen Terrain File |
| term | Apple Terminal Data |
| terrain | Terragen Terrain File |
| terrn | Rigs of Rods Terrain Data |
| terrn2 | Rigs of Rods Terrain Data |
| tet | Textease Database CT Single-user Database Template |
| tew | Bentley InRoads Text Export Wizard Data |
| tex0 | Nintendo Wii Texture Data |
| texter | Texter Snippet Data |
| textfactory | BBEdit Text Factory Data |
| tf10 | IRIG 106 Data Transfer Data |
| tfa | TreeSoft CashFlow Analysis Data |
| tfam | PLINK Individual Information File |
| tfh | Borland Turbo Profiler Help Data |
| tfl | ALKFLOW Total Flow Data |
| tfl | Tific Client Data |
| tfr | 4D Database Windows Formula Document |
| tfrm | 4D Database Mac OS X Formula Document |
| tfv | YETI Vegetation Plot Database Export File |
| tfx | Avid Pro Tools Eleven Rack Presets |
| tfz | FBS Vehicle Database |
| tg3 | TexGen 3 Geometry Data |
| tgc | Terragen Clip File |
| tgd | Terragen 2 World |
| tgf | Stonevoice Translator Tag Data |
| tgf | libigl Control Handle Graphs |
| tgl | SkyMap Target Lists |
| tgmd | WDTV ThumbGen Movie Metadata |
| tgmg | TabGroups Manager for Firefox Exported Group Data |
| tgo | Terragen Object File |