| crp1 | LG 2-3G Tool Firmware |
| crplugin | ComicRacks Plugin |
| crt | Certificate File |
| csr | Certificate Signing Request |
| csu | Crestron Software Update |
| cuj | Personal Backup Saved Task |
| cursemod | Curse Client Mod |
| cvr | Microsoft Crash Report |
| cvt | ACDSee Canvas External Tool |
| cxn | Conexant Modem Driver |
| cya | CYANA Macro File |
| d2a | AviSynth MPASource Plug-in |
| dbase | Aston-Tate dBASE Database |
| dbf | Aston-Tate dBASE Database |
| dcover | Disc Cover |
| der | Certificate File |
| desklink | Windows Desktop Shortcut |
| develve | Develve Data File |
| devicesalt | NOOK Device Salt |
| dfk | D Fusion Key File |
| dfp | Fusion Plugin |
| dfu | iOS Device Firmware Upgrade File |
| dfu | DFUWizard Firmware Image |
| dgaddin | DigiGuide Add-in |
| dhv | Doc-To-Help File Lock |
| diagcab | Windows Troubleshooting Pack Cabinet |
| diagpkg | Windows Troubleshooting Pack Data |
| diff | Diff Output |
| dimax | DiMAX Firmware Image |
| directory | KDE Desktop Folder View Properties |
