| cdt6 | CorelDraw 6 for Mac Template |
| cdtx | ConceptDraw PROJECT XML Template |
| cdw | KOMPAS 3D Drawing |
| cdw | CeledyDraw Document |
| cdx | ChemDraw Exchange Document |
| cdxml | ChemDraw XML Document |
| cdy | Cinderella Construction File |
| ce3 | Calendar Creator v3 Document |
| cedx | CardExchange 7 Card Design |
| cer | Broderbund PrintMaster Certificate |
| cg | Guitar Chord Groover Chord |
| cg3 | Cabri 3D Document |
| cgr | Catia V5 Drawing |
| ch3 | Harvard Graphics 3.0 Chart |
| ch4 | Micrografx Charisma 4.0 Presentation |
| chai | Chaimera Artwork Document |
| chait | Chaimera Artwork Document Template |
| chd | Chordastic Chord |
| che | Stitch & Sew Embroidery Design |
| chm | Compiled HTML Help |
| cho | Chord Pro Chord |
| chopro | Chord Pro Chord |
| chord | Guitar Chord File |
| chp | Corel Ventura Chapter |
| chrt | KDE KChart Document |
| cht | Chemtool Document |
| chtml | Compact HTML Document |
| cida | xplorer2 Scrap Document |
| cil | Microsoft ClipArt Gallery Download Package |
| cip | InPrint 2 Document |
| circuit | KTechlab Circuit Design |
| cit | BibExcel Cited Document |
| ckd | Kubotek KeyCreator Design Container |
| ckt | CircuitMaker Document |
| cl2doc | Comic Life 2 Document |