The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- CitizenCon 2019 sessions (2 members)
- CitizenCon 2020 images (1 member)
- CitizenCon 2022 (1 member)
- CitizenCon 2023 images (8 members)
- CitizenCon 2948 (1 member)
- CitizenCon images (1 member)
- CitizenCon sessions (1 member)
- Citizencon 2018 (9 members)
- Citizens (1 member)
- City Districts (2 members)
- City Lights (25 members)
- Civilian Carrack-class vessels (2 members)
- Civilian Chariot-class vessels (1 member)
- Civilian Constellation-class vessels (1 member)
- Civilian Defense Force images (2 members)
- Civilian Freelancer-class vessels (1 member)
- Civilian Hammerhead-class vessels (1 member)
- Civilian Idris-Class Vessels (4 members)
- Civilian Mercury-class vessels (1 member)
- Civilian computers (8 members)
- Civilian mining laser heads (0 members)
- Civilian radars (8 members)
- Civilian vessels of unknown class (5 members)
- Civilians (1 member)
- Clark Defense Systems (391 members)
- Clash armor images (2 members)
- Clash images (5 members)
- Clean Shot (16 members)
- Cleaver images (5 members)
- Clio (4 members)
- Clio images (15 members)
- Cloak images (1 member)
- Closed issues (4 members)
- Clothing (18 members)
- Clothing images (165 members)
- Clothing industry (29 members)
- Clothing set (4 members)
- Cloud Imperium Staff images (8 members)
- Cloud Imperium images (9,488 members)
- Cloudview Center images (10 members)
- Cmn (0 members)
- Cmn-3 (0 members)
- Coda images (11 members)
- Code Blue Apparel (92 members)
- ColdSnap images (1 member)
- Cole (1 member)
- Collision Course (3 members)
- Colonial outpost (1 member)
- Colonial structures (1 member)
- Combat Missions (4 members)