| tcnm | TestComplete Name Mapping Project Data |
| tcnunit | TestComplete NUnit Test Data |
| tcodt | TestComplete Object-Driven Testing Project Data |
| tcomp | Tome Editor Component Data |
| tcs | Topocad Cross Sections |
| tcscript | TestComplete Script Project Data |
| tctas | TestComplete Tested Applications Project Data |
| tctbl | TestComplete Table Elements Data |
| tctbls | TestComplete Tables Settings Data |
| tctest | TestComplete Unit Test Data |
| tcu | Tibbo Composite Uncompressed Data |
| tcusrfrm | TestComplete Single User Form Data |
| tcusrfrms | TestComplete User Forms Project Data |
| tcvis | TestComplete Test Visualizer Index |
| tcwat | TestComplete Web Accessibility Data |
| tcwcm | TestComplete Web Comparison Data |
| tcws | TestComplete Web Service Project Data |
| tcwtc | TestComplete WebTesting Collection Data |
| tcx | Tacx Exported Training Data |
| tczip | Tekla Structures Exported Data |
| tczl | Tiny Core Linux Xlib |
| tda | Palm To-Do Archive |
| tda3mt | DivX Author Template |
| tdata | Tome Editor Data |
| tdb | SlamDB Database |
| tdc | Tableau Data-connection Customization File |
| tddd | Imagine 3D Data Description File |
| tde | Tableau Data Extract |
| tdf | DVD X Copy TDF File |
| tdf | Guide Text Definition File |
| tdf | XTrans Data |
| tdh | Borland Turbo Debugger Help Data |
| tdo | Xilinx Text Design Output |
| tdp | Serif DrawPlus Thumbnail |
| tdr | Keysight PLTS TDR Calibration Data |