| cflt | CATS Flat File |
| cfog | Cloudfogger Encrypted Data |
| cfp | Intuit Quickbooks Cash Flow Projector File |
| cfs | Lucene Single Compound File |
| cft | Microsoft SQL Server Data Replication Conflict Tables |
| cfv | CFView Data |
| cfw | ChemFinder Form File |
| cfx | CFX Case File |
| cfx | Lucene 2 Compound File |
| cfx | Picasa Collage Data |
| cgc | Compressed Gamecube Disk Image |
| cgd | CricketGraph Data |
| cgk | BlueSoleil Driver Data |
| cgn | PoldatDB Data |
| cgns | CFD General Notation System Data |
| cgp | PixelCryptor Encrypted File |
| cgrp | Avid Pro Tools Clip Group File |
| cgt | SmartCAM Code Generation Template |
| cgx | Autodesk Land Desktop Label Style |
| ch10 | IRIG 106 Original Recording Data |
| ch5 | VisIt CH5 Data |
| ch6 | ZX-Paintbrush Character Data |
| ch8 | ZX-Paintbrush Character Data |
| cha | Adobe Photoshop Channel Settings |
| char | Nintendo DS Character Tile Data |
| chatlog | Adium Chat Log |
| chb | CHMReader.NET Internal Data |
| chb | OLE DB Checkbook Data |
| chc | HCFR Colorimeter Data |
| chck | Microsoft Exchange Database Check Data |
| check | CASTEP Check Binary |
| chem | TI bqEASY Chemistry Data |
| chg | Quicken Online Data |
| chg | Windows Netlogon ChangeLog |
| chj | IBM SPSS Interview Cache |