The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Article message templates (24 members)
- Article message templates with missing parameters (11 members)
- Articles containing Arabic-language text (1 member)
- Articles containing Japanese-language text (2 members)
- Astra Per Aspera Sector (1 member)
- Astralis Vertex Sector (1 member)
- Ataraddon Sector (7 members)
- Autonomy (2 members)
- Bars and Lounges (5 members)
- Beeria Sector (8 members)
- Bellatrix Antares Sector (6 members)
- Blazing Umbra (76 members)
- Blazing Umbra Characters (233 members)
- Blazing Umbra Non-Player Characters (80 members)
- Blazing Umbra Organizations (6 members)
- Book stub templates (1 member)
- CS1 errors: empty citation (2 members)
- CS1 errors: missing title (2 members)
- CatAutoTOC generates no TOC (1 member)
- CatAutoTOC on pages where PAGESINCATEGORY returns zero (1 member)
- Category namespace templates (1 member)
- Characters Not in the Game (4 members)
- Computer Systems (0 members)
- Computer science navigational boxes (1 member)
- Conceptions of self (0 members)
- Concepts in the philosophy of mind (1 member)
- Conformity (1 member)
- Control (social and political) (1 member)
- Crimson Horizon Sector (3 members)
- Cross Setting Characters (6 members)
- Cross Setting Non-Player Characters (1 member)
- Culture (1 member)
- Cybernetics (24 members)
- Danish writer navigational boxes (1 member)
- Dark triad (1 member)
- Darkian Churarius Sectors (1 member)
- Darkian Churarius Star Systems (2 members)
- Data templates (2 members)
- Decommissioned (1 member)
- Deletion Issues (4 members)
- Delphi (1 member)
- Delta Nadacan Sector (9 members)
- Denied Characters (0 members)
- Denied or Banned (3 members)
- Denied or Banned Characters (0 members)
- Destroyed Facilities (2 members)
- Disambiguation (28 members)
- Disambiguation message boxes (1 member)
- Documentation assistance templates (1 member)
- Documentation see also templates (1 member)