| syx | MIDI System Exclusive Message |
| syz | SYSTAT Data |
| sy_ | Compressed SYS File |
| sz | WinAMP Skin |
| sz4 | E-triloquist Phrase Library |
| szs | Wii Game Data |
| szt | Super ZZT Game Creation System Data |
| szx | Spectaculator ZX-State Snapshot |
| t$ab | Timbuktu Pro Address Book Data |
| t$m | AVG Internet Security Temporary File |
| t00 | TaxCut Federal Data |
| t01 | TaxCut Federal Data |
| t02 | TaxCut Federal Data |
| t03 | TaxCut Federal Data |
| t04 | TaxCut Federal Data |
| t05 | TaxCut Federal Data |
| t06 | TaxCut Federal Data |
| t07 | TaxCut Federal Data |
| t08 | TaxCut Federal Data |
| t09 | TaxCut Federal Data |
| t10 | IRIG 106 Data Transfer Data |
| t12 | At Home 2012 Tax Return Data |
| t13 | At Home 2013 Tax Return Data |
| t15 | H&R Block 2015 Tax Return Data |
| t16 | H&R Block 2016 Tax Return Data |
| t2flow | Taverna v2 Workbench Workflow Definition |
| t2g | Kallisto Transcript to Gene Data |
| t2k | Teach2000 Document |
| t2ks | Teach2000 Student Answers File |
| t2kt | Teach2000 Exam File |
| t2s | Tier2 Submit Data |
| t32 | PowerQuest Drive Image 5 Data |
| t3a | Swift 3D Animation Preset Data |
| t3d | TicTacTi Advertisement Definition |
| t3g | Sunpinyin Data |