| tii | Lucene Term Info Index |
| tiip | DXF-TIIP Pattern Data |
| tika | Apache Tika Data |
| time | Light Time |
| timeline | Timeline Data |
| timg | Playground OSS Image Data |
| tin | Bentley GEOPAK Environmental Modeling Systems Data |
| tin | Carlson 2016 Triangulated Irregular Network Data |
| tin | WMS Triangulated Irregular Networks Data |
| tin | WRAP TABLES Input Data |
| tinf | Microsoft Windows Theme Info |
| tiny | Gnome Desktop Tiny Data |
| tiq | Tektronics RSA306 TIQ Data |
| tis | Lucene Term Infos |
| tis | Tru-Designer Captured Device Settings Data |
| tis | TruKnox Tru-i Suite Data |
| tit | CXTerm Text Input Table |
| tit | Novapoint Horizontal Alignment Data |
| tjexp | The Journal Exported Data |
| 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 |
