The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Cloudview Center images (6 members)
- Cmn (0 members)
- Cmn-3 (0 members)
- Coda images (7 members)
- Cole (1 member)
- Combat Missions (3 members)
- Combat knives (8 members)
- Comm-Link (43 members)
- Comm-Link images (282 members)
- Comm-link images (3 members)
- Comm Arrays in Stanton System (16 members)
- Commercial buildings (2 members)
- Commodities (24 members)
- Commodity (52 members)
- Commodity icons (77 members)
- Communications from Chris Roberts (0 members)
- Community (5 members)
- Community Events (50 members)
- Companies (269 members)
- Company & organization logos (329 members)
- Company Logos (1 member)
- Compensators (3 members)
- Competition computers (2 members)
- Competition coolers (6 members)
- Competition power plants (5 members)
- Competition quantum drives (4 members)
- Competition radars (1 member)
- Competition shield generators (6 members)
- Component Images (2 members)
- Components (7 members)
- Computer system manufacturers (1 member)
- Computers (34 members)
- Concept Art (1 member)
- Concierge Items (11 members)
- Congress Now (0 members)
- Consolidated Outland (8 members)
- Constantine Hurston (1 member)
- Constellation Andromeda images (95 members)
- Constellation Aquila images (35 members)
- Constellation Images (1 member)
- Constellation Phoenix images (48 members)
- Constellation Taurus images (37 members)
- Constellation series (11 members)
- Consumables (4 members)
- Consumer electronics (1 member)
- Consumer goods (5 members)
- Containers (12 members)
- ContainsSEO (0 members)
- Controls (2 members)
- Convention centers (4 members)