| dbw | DataBoss Database |
| dbwal | iOS CalDAV Temporary Sync Data |
| dbx | Alteros 3D Thumbnail Cache |
| dbx | Autodesk AutoCAD Database Extension |
| dbx | Dropbox Encrypted Database |
| dbx | Microsoft Outlook Express Folder Database |
| dby | Dolby CP650 Data |
| dbz | DB Zipper Archive |
| dc | Microsoft SMS Collection Evaluator Deletion Data |
| dc | SPICE DC Data |
| dc1 | Bloomba E-mail Message |
| dc2 | Kodak Photo-Enhancer DC2 Data |
| dc4 | ViaThinkSoft DeCoder 4 File |
| dca | Visual Basic Active Designer Cache |
| dcb | Concordance Database |
| dcb | DAZ Studio Custom Brick |
| dcb | TrialDirector Concordance Database |
| dcd | CHARMM DCD File |
| dcd | DisCryptor Encrypted Database |
| dce | Autodesk AutoCAD DCL Error Log |
| dce | BricsCAD Dialog Error Log |
| dcext | DC++ Extension Plugin |
| dcf | DisCryptor Encrypted Archive |
| dcf | DOpus Command File |
| dcf | OMA DRM Content Format |
| dcf | WordExpress Dictionary Data |
| dcf | WRAP Daily Flows Columnar Data |
| dch | Draft Choice Drawing |
| dck | Resolume Deck |
| dck | Warajevo Emulator Data |
