| dck | Resolume Deck |
| dck | Warajevo Emulator Data |
| dcl | Autodesk AutoCAD Dialog Definition Data |
| dcl | BricsCAD Dialog Control Language Data |
| dcl | DesignComposer Design Command Language File |
| dcl | DumpSec Report |
| dcm | DiskCatalogMaker Catalog Data |
| dcmd | DiskCatalogMaker Thumbnail-Enabled Catalog Data |
| dcmf | DiskCatalogMaker Catalog Data |
| dcn | Autodesk AutoCAD Civil 3D Depth Slope Definition |
| dcn | VerdiCash Digital Cash Note |
| dcover | Belight Disc Cover Data |
| dcp | OS/2 Warp Data Codepage |
| dcpie | DocumentsCorePack Import/Export Tool Data |
| dcpy | Disk Copy Data |
| dcr | Adobe Director Shockwave Media Data |
| dcr | AstroVIEW X Data Log |
| dcs | AcaStat Data |
| dcs | Act! Activity Data |
| dcs | QuarkXPress Desktop Color Separation Data |
| dcsdb2 | 3DCS Database |
| dct | Adobe Illustrator Dictionary |
| dct | Autodesk AutoCAD Dictionary Data |
| dct | Concordance Dictionary Database |
| dct | DeSmuME ROM Cheats Data |
| dct | E-Sword v8 Dictionary Data |
| dct5 | Microsoft Word 5 for Mac Dictionary Data |
| dctmp | DC++ Partially Downloaded |
| dctx | E-Sword v9 Dictionary Data |
| dctx | Microsoft Office IME Extended Dictionary Data |
