The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- 1920 standard tanker (0 members)
- 1920 standard tanker Images (5 members)
- Agricultural Products (7 members)
- April Fools (4 members)
- April Fools Images (16 members)
- Article management templates (1 member)
- Babel - Users by language (3 members)
- Braked 1920 standard tanker Images (3 members)
- CC-zero files (17 members)
- CC Files (1 member)
- CC Icons (8 members)
- Candidates for deletion (0 members)
- Cargo (10 members)
- Chemicals (7 members)
- Cities (5 members)
- Coach Images (31 members)
- Coaches (22 members)
- Companies (1 member)
- Construction Materials (8 members)
- Creative Commons Attribution-ShareAlike 4.0 files (115 members)
- Creative Commons Attribution 4.0 files (1 member)
- DMU (7 members)
- DPL Template (5 members)
- Diesel (12 members)
- Disambiguations (2 members)
- Documentation templates (1 member)
- Doubleheading (33 members)
- En (1 member)
- En-5 (1 member)
- Engine Images (4 members)
- Engines (45 members)
- File management templates (5 members)
- Files (3 members)
- Fr (1 member)
- Fr-1 (1 member)
- Freight (7 members)
- Game Interface Images (2 members)
- Gamepass (1 member)
- Gamepass Images (4 members)
- General Goods (15 members)
- General Templates (1 member)
- General wiki templates (4 members)
- Guides (1 member)
- Help (1 member)
- Hidden categories (2 members)
- Images (34 members)
- Imported vocabulary (8 members)
- Info (10 members)
- Infobox templates (5 members)
- Interface icon (4 members)