| Abbreviation | Definition |
|---|---|
| DCU | Delphi Compiled Unit |
| DCX | Bitmap graphics (Multipage PCX - many faxes) |
| DCX | Zsoft multipage Paintbrush image format |
| DD | Compressed Macintosh file archive (DiskDoubler) |
| DDB | Bitmap graphics |
| DDE | Dynamic Data Exchange (binary) |
| DDF | BTRIEVE Database file |
| DDF | Data Description File |
| DDF | Database Definition File |
| DDFS | Digital Document Digital Document File Sustem |
| DDFS | Digital Document Digital Document File Sustem |
| DDI | DiskDupe Disk image file |
| DDIF | Bitmap graphics (DEC DDIF file) |
| DDP | OS/2 Device Driver Profile file |
| DDW | Double Data Word |
| DEB | Debug script |
| DEC | Decoded file |
| DEF | Defaults - definitions |
| DEF | Design Exchange Format |
| DEF | Geoworks Esp Assembly header file |