The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Cooler images (34 members)
- Coolers (88 members)
- Cordimon images (1 member)
- Corel System (11 members)
- Coreless Planet (7 members)
- Corsair images (69 members)
- Corsair series (0 members)
- Corvette (0 members)
- Corvettes (6 members)
- Cosplay (1 member)
- Counterfeit (4 members)
- Covalex Hub Gundo images (7 members)
- Crawler Images (1 member)
- Creative Commons Attribution-NonCommercial-ShareAlike 2.0 files (16 members)
- Creative Commons Attribution-NonCommercial 2.0 files (108 members)
- Creative Commons Attribution-ShareAlike 2.0 files (4 members)
- Creative Commons Attribution-ShareAlike 2.5 files (43 members)
- Creative Commons Attribution-ShareAlike 3.0 files (5 members)
- Creative Commons Attribution-ShareAlike 4.0 files (4,897 members)
- Creative Commons Attribution 2.0 files (9 members)
- Creative Commons Attribution 2.5 files (1 member)
- Creative Commons Attribution 3.0 files (8 members)
- Creative Commons Attribution 4.0 files (42 members)
- Creative Commons Attribution files (5 members)
- Creative Commons ShareAlike files (3 members)
- Creative Commons files (10 members)
- Croshaw System (12 members)
- Crossbows (1 member)
- Crucible Images (10 members)
- Cruisers (0 members)
- Crusader (2 members)
- Crusader AO Missions (24 members)
- Crusader FPS Cave Missions (2 members)
- Crusader Industries (28 members)
- Crusader Security images (1 member)
- Crusader images (35 members)
- Cruz Images (1 member)
- Cruz images (3 members)
- Cryptokeys (7 members)
- CureLife (11 members)
- Currency (3 members)
- Custodian images (17 members)
- Cutlass Black images (119 members)
- Cutlass Blue images (41 members)
- Cutlass Red images (46 members)
- Cutlass Steel images (17 members)
- Cutlass series (4 members)
- Cutter Scout images (0 members)
- Cutter images (47 members)
- Cutter series (0 members)