The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- CommonState (1 member)
- Communication templates (1 member)
- Community Administration (16 members)
- Community administration (0 members)
- Computer keys (2 members)
- Connecticut (7 members)
- Construction (133 members)
- Convert to subpage (0 members)
- Convert to subpages (12 members)
- Country list (2 members)
- Cross-reference templates (1 member)
- Custom color scheme (1 member)
- Date-computing templates (4 members)
- Delaware (1 member)
- Disambiguation (29 members)
- Disambiguation and redirection templates (3 members)
- District of Columbia (1 member)
- Doctorblah (1 member)
- Documentation assistance templates (2 members)
- Documentation pages (7 members)