| svdl | Security Validation Description Language Document |
| svh | SystemVerilog Include File |
| svn | Subversion Data File |
| svn-base | Subversion Base Data |
| svn-work | Subversion Cache |
| svntmp | Subversion Temporary Data |
| svq | SAS 6 Sequential Engine View Data |
| sw | Free Pascal Assembler Data |
| swag | Swag Data |
| swc | Shockwave Flash Component File |
| swd | Shockwave Flash Debug |
| swift | Swift Source Code |
| swt | Shockwave Flash Template |
| sxp | OpenOffice.org Script |
| syds | Essential Studio Data Sources Data |
| sydx | Syncfusion Dashboard Data |
| syp | SYP Script |
| sysml | Systems Modeling Language Document |
| systag | Android System Tag Data |
| syt | Sytes Template File |
| t | ReaGeniX Code Generator Tester Symbol Table |
| t | Tom Source Code |
| t | Turing Source Code |
| t2p | Tex2Page Macro Code |
| t3i | WebFOCUS TScom3 Script |
| t3o | WebFOCUS TScom3 Log |
| t6i | Mazak 640-MT Mazatrol Program |
| t6m | Matrix Mazatrol Program |
| taasmt | thinAir Assembly Template |
| tacls | Tangible Class Diagram |
