| tkx | TK Solver Package |
| tl5 | Timeliner 5 Data |
| tlb | HP OpenVMS Text Library |
| tlb | Portfolio Automation Interface Data |
| tlb | TrialDirector Toolbar Data |
| tlb | VAX Text Library |
| tlbackup | True Launch Bar Settings Backup |
| tlbbackup | True Launch Bar Settings Backup |
| tlbplugin | True Launch Bar Plugin |
| tlc | TINA Logic Converter Data |
| tlc | Topocad Layer Collection Data |
| tld | PTC Creo Thermal Temperature Load Data |
| tld | TINA Library Descriptor |
| tld | Trellix Document Design Data |
| tle | dpsVelocity Timeline Data |
| tle | STK Two-line Element Sets |
| tlf | QUANTA Template File |
| tlf | Timing Library Format File |
| tlic | ClickOnce Trust License Data |
| tlist | Geomview Transformation Matrices Data |
| tll | LG TV Link-Loader File |
| tlm | Spektrum DX8 Telemetry Log |
| tlm | Timeline Maker Timeline Data |
| tln | HyperLynx LineSim Schematic |
| tlo | SPSS Table Look File |
| tlog | ArduCopter Telemetry Log |
| tlog | Oracle Database Transaction Log |
| tlr | Tableau Offline License Registration Data |
| tlst | GibbsCAM Tool List Data |
| tlsv | Topcon TopSURV Database |
