| .cdd |
ConceptDraw PRO Document |
| .cdb |
Symbian Phonebook Database |
| .catproduct |
CATIA V5 Assembly File |
| .clg |
Windows Catalog File |
| .chr |
Doki Doki Literature Club! Character File |
| .cdmm |
ConceptDraw MINDMAP Document |
| .cub |
Analysis Services Cube File |
| .cdx |
Compound Index File |
| .cdf |
Computable Document Format File |
| .cst |
Manga Studio Story File |
| .clp |
CrazyTalk Clip File |
| .cddz |
ConceptDraw PRO Document |
| .cma |
Coach Activity File |
| .crypt12 |
WhatsApp Encrypted Database File |
| .chk |
InterCheck Checksum Database |
| .cwk |
ClarisWorks Document |
| .cil |
Clip Gallery Packaged File |
| .cdt |
CD-Text File |
| .cv5 |
Canvas 5 Drawing File |
| .cod |
Compiled Source Code |
| .clkx |
Clicker Grid Set |
| .cmx |
Corel Metafile Exchange Image File |
| .cam |
Gerber CAM Job File |
| .chw |
Compiled Help Index File |