The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Airbus (2 members)
- Airline logos (36 members)
- Airlines (20 members)
- Airport CEO (3 members)
- Airport CEO/zh (1 member)
- Airport CEO Wiki (12 members)
- Articles (2 members)
- Baggage (1 member)
- Baggage Icons (5 members)
- Boeing (6 members)
- Candidates for deletion (3 members)
- Candidates for speedy deletion (0 members)
- Citation needed (0 members)
- Cleanup (0 members)
- Community (4 members)
- Copyright templates (12 members)
- Disambiguations (0 members)
- Documentation templates (65 members)
- Formatting templates (26 members)
- Front page sections (9 members)
- Fuel (2 members)
- Gameplay (5 members)
- Gameplay mechanics (0 members)
- Guides (4 members)
- Hidden categories (0 members)
- Icons (2 members)
- Images (6 members)
- Images from pre-alpha (57 members)
- Images needing improvement (0 members)
- Infobox part templates (7 members)
- Infobox templates (8 members)
- Infrastructure (12 members)
- Legal notices (3 members)
- Management (10 members)
- Media (2 members)
- Navigation templates (6 members)
- Notice templates (17 members)
- Pages to be merged (0 members)
- Pages to be moved (0 members)
- Pages with broken file links (0 members)
- Plane images (52 members)
- Planes (34 members)
- RU translation (4 members)
- Screenshots (31 members)
- Skin Images (0 members)
- Structure Icons (27 members)
- Stubs (19 members)
- Talk templates (1 member)
- Template documentation (2 members)
- Templates (20 members)