| cl | QIP Contact List Data |
| cl2 | Hy-Tek Meet Manager Results Data |
| cl7 | Free Clipboard Viewer Saved Data |
| clam | Adobe InDesign User Dictionary Data |
| classlist | SMART Notebook Class List |
| clb | Corel Mosaic 5.0 Library |
| clb | ICQ Contact List Data |
| clb | NoteTab Clipbook Library |
| clbu | Android Call Log Backup |
| clbx | MP3 Automagic CD Cover Creator Label |
| clc | Corel Mosaic 5.0 Catalogue |
| clc | Schedule Plus Habits Mission Statement Data |
| clc | UltimaCalc Data |
| clct | RootCause Collect Data |
| cld | ClamAV Local Database |
| cld | Terragen Cloud Layer Data |
| cldcvt | CD-LabelPrint Converted Data |
| cldlyr | Terragen Cloud Layer Data |
| cle | Icon Lock-iT XP Locked File Indicator |
| clean | Instagram for Android Cache Data |
| clf | DesignWorks Library |
| clf | ListPro Data |
| clf | Source Insight Custom Language Data |
| clf1 | Common Loudspeaker Format Type 1 File |
| clf2 | Common Loudspeaker Format Type 2 File |
| clg | QIP Ignored Contact List Data |
| clh | NoteTab Clip Assistant List |
| cli | AquaCrop Climate Data |
| clib | CATS Library File |
| clipping | Mac Text Clipping Data |
| clk | ClickFORMS Data |
| clkc | Clicker Connect Set |
| clkk | Clicker Keyboard |
| clkm | Clicker Matching Set |
| clkp | Clicker Palette |
