| 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 |
| 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 |
| cha | Adobe Photoshop Channel Settings |
| chc | HCFR Colorimeter Data |
| check | CASTEP Check Binary |
| chem | TI bqEASY Chemistry Data |
| chg | Windows Netlogon ChangeLog |
| chg | Quicken Online Data |
| chk | DB/TextWorks Check Textbase Problem Report |
| chk | Saved File Fragment |
| chk | Epidata Defined Checks |
| chk | Gaussian Checkpoint File |
| chls | Charles Session Data |
| chn | MODTRAN CHN Output File |
