| tjf | VAXTPU Backup Data |
| tji | TaskJuggler Include File |
| tjl | HP OpenVMS ACL Editor Journal Data |
| tjp | TaskJuggler Project File |
| tjvdb | The Journal Volume Database |
| tjxml | The Journal Export Data |
| tk1 | Wintec WBT-201 TK1 Tracklog |
| tk2 | Wintec WBT-201 TK2 Tracklog |
| tk3 | Wintec WBT-201 TK3 Tracklog |
| tk4 | Wintec WSG-1000 Mark Database |
| tk5 | eXtendable Wad Editor TK5 Data |
| tka | Genie 2000 Measurements Data |
| tkb | TicketBench Data |
| tkc | MetaTrader 5 Tick Data |
| tkd | Wikit TKD Database |
| tkfl | TKLinks Saver Favorite Links |
| tki | Tkined Data |
| tkined | Tkined Configuration Data |
| tkr | eSignal Ticker Data |
| tks | NI Traktor Pro MIDI Map |
| tkt | TK Solver Data |
| tkw | TK Solver Data File |
| tkx | TK Solver Package |
| tl5 | Timeliner 5 Data |
| tlb | HP OpenVMS Text Library |
| tlb | TrialDirector Toolbar Data |
| tlbackup | True Launch Bar Settings Backup |
| tlbbackup | True Launch Bar Settings Backup |
| tlbplugin | True Launch Bar Plugin |
| tlc | TINA Logic Converter Data |
