| 11. | .sdml | Spacial Data Modeling Language |
| 12. | .sdn | Software Distribution Network compressd file archive (pak251.exe) |
| 13. | .sdp | Datafile (Cocreate SolidDesigner) ◊ Scalable Multicast (RealAudio) |
| 14. | .sdpc | Datafile (Cocreate SolidDesigner) |
| 15. | .sdr | Drawing (SmartDraw) ◊ Music (Sounder) |
| 16. | .sds | MIDI Sample DUMP Standard File |
| 17. | .sdt | Template (SmartDraw) |
| 18. | .sdts | Spatial Data Transfer Standard |
| 19. | .sdv | Semicolon Divided Values file |
| 20. | .sdw | Datafile (Scenery data for Windows) ◊ Sound (Raw Signed DWord (32bit) data) ◊ Vector graphics (Ami Draw) |