| tcls | TestComplete Configuration File |
| tcnet | TestComplete Configuration Reference File |
| tds | TerrAlign Dataset Configuration |
| tel | NCSA Telnet Configuration File |
| ter | CorelFlow Line Terminator Data |
| terminal | Terminal Settings Data |
| tf | Borland Turbo Configuration |
| tfa | Aston Theme Configuration |
| tfd | TFSImage Settings |
| tgb | TheGreenBow VPN Client Configuration |
| thc | AbleCommerce Wizard Theme Configuration |
| thc | Therion Configuration File |
| ti0 | Tabula Initialization Data |
| ti1 | Tabula Initialization Data |
| ti2 | Tabula Initialization Data |
| timer | Systemd Service Timer Configuration |
| tiw | Bentley InRoads Wizard Settings Data |
| tlp | Tunnelier Profile |
| tlset | Text Locker Settings |
| tm | Tecmail Configuration |
| tmap | TI PowerLAN Configuration |
| tn7 | Casio WK-3000 User Tones |
| toe | TouchDesigner Environment |
| tofp | Toshiba Fingerprint Utility Settings |
| tol | Zemax Tolerance Settings |
| top | IBM Netfinity Server Rack Configurator Data |
| top | Zemax Tolerance Settings Data |
| tos | The Only Sheet Settings Data |
| tpp | Topo Explorer Preferences Data |
| tprc | Terminal-Plus Script |
| tps | Treepad Settings File |
| tpx | TinyTERM Connection Settings Data |
| tr2 | Borland Turbo Debugger Session-state Settings Data |
| trm | Terminal Settings |
| tsi | NI Traktor Settings File |
