The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Advanced Trains Tutorials (1 member)
- Albums by Artist (1 member)
- Albums by John Oestmann (1 member)
- Article message templates (1 member)
- Article message templates with missing parameters (1 member)
- Articles (5 members)
- Articles containing Chinese-language text (3 members)
- Articles using infobox body of water without image bathymetry (1 member)
- Articles using infobox body of water without pushpin map (1 member)
- Articles with hatnote templates targeting a nonexistent page (3 members)