| 1. | .sy1 | Smartpix symbol library (Ami Pro) |
| 2. | .sy3 | Symbol file (Harvard Graphics 3.x) |
| 3. | .syd | Backup (QEMM - Sysedit) |
| 4. | .syk | SYLK spreadsheet format (Excel) |
| 5. | .sylk | SYLK spreadsheet format (Excel) |
| 6. | .sym | Component symbols (P-CAD) ◊ Graphics symbols (Harvard Graphics 2.0 - Microsoft Windows SDK) ◊ Precompiled headers (Borland C++) ◊ Program symbol table (many compilers and linkers) &#… 0.3 KB |
| 7. | .syn | Bitmap graphics (SDSC Synu image file) ◊ Synonym file (Microsoft Word 5) |
| 8. | .synu | Bitmap graphics (SDSC Synu image file) |
| 9. | .sys | Datafile (SYGRAPH - SYSTAT - SPSS/PC) ◊ System file - device driver or hardware configuration info (DOS) |
| 10. | .syw | Graphics symbols (Harvard Graphics Win) ◊ Wave File (Yamaha SY-85/SY-99) |
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