| tyimport | Typinator Set Import Data |
| tym | Adobe Pagemaker Timestamp Data |
| tyset | Typinator Set File |
| tza | TZ Medical Aera-CT Data |
| tzd | Netscape Communicator Locale Data |
| tzl | SketchUp Custom Location Data |
| tzx | ZX Spectrum Emulator Tape Data TZX |
| u | Nitpicker IP Flow Data |
| u | Unreal Engine Data |
| u01 | Barudan Embroidery Data |
| u08 | UFile 2008 Tax Return Data |
| u10 | UFile 2010 Tax Return Data |
| u11 | UFile 2011 Tax Return Data |
| u12 | UFile 2012 Tax Return Data |
| u14 | Embird Embroidery Data |
| u2n | Baan ERP Unicode to Native Mapping Data |
| u32 | Adobe Authorware Cover File |
| u3d | Ultimate 3D Engine Model |
| u96 | EasyZip Temporary Data |
| ual | Entrust Auto-enrollment Server Unattended Login Credentials |
| uamodel | OPC-UA Model Data |
| uap | SIMATIC WinCC User Archive Export |
| ubd | UltraBac Data |
| ubj | Universal Binary JSON Data |
| ubjson | Universal Binary JSON Data |
| ubm | Apple iPhoto mtwain Install Data |
| ubox | Universe Sandbox Simulation Data |
| ubs | Microsoft BugsLayer Data |
| ubu | UEFI BIOS Updater Data |
| ucc | National UCC Fininacing Statement Data |
