The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Guam (1 member)
- Guideline properties (16 members)
- Hatnote templates (5 members)
- Hatnote templates documentation (1 member)
- Hawaii (1 member)
- Hidden categories (3 members)
- Hidden tags (25 members)
- IPhone (1 member)
- IPhone Instructions (0 members)
- ISO date templates (1 member)
- Icons (14 members)
- Idaho (1 member)
- Illinois (3 members)
- Image required (9 members)
- Image templates (1 member)
- Images (2 members)
- Improper wiki style (0 members)
- Incomplete templates (19 members)
- Index (23 members)
- Indexed pages (2 members)