| tbi | The Bat! Message Index |
| tbio | Toxic Biohazard Presets Data |
| tbk | DBase Memo Backup Data |
| tbl | ARIA CNS Table Data |
| tbl | ArcVIEW Geocode Support Table |
| tbl | Pro/ENGINEER Table |
| tbm | Tableau Bookmark Data |
| tbo | Turbo Architecture Database |
| tbpd | Toon Boom Studio for Mac Project Directory |
| tbr | Norton Desktop Custom Toolbar |
| tbs | DB/TextWorks Persistent Scripting Information |
| tbu | DB/TextWorks Textbase User File |
| tbu | SDL Passolo Translation Bundle |
| tbv | Turbo-BrainVoyager Data |
| tbw | ModelSim Test Bench Waveform |
| tbx | TermBase eXchange Data |
| tc1 | GeoTide Harmonic Location Constants Data |
| tc2 | GeoTide Vector Stream Prediction Constants Data |
| tcap | HP OpenCall TCAP File |
| tcax | TestComplete Events Project Data |
| tcb | Tokyo Cabinet Database |
| tcc | Tibbo Composite Compressed Data |
| tcdb | Tokyo Cabinet Database |
| tcdock | TestComplete Panel Layout Data |
| tce | STK Two-line Element Sets |
| tcf | Topocad Camber Diagram |
| tcg | Trading Card Game Data |
| tcgb | TCGB Data |
| tcia | TCIA Manifest Data |
| tckdt | TestComplete Keyword Test Data |