The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Hatnote templates with errors (0 members)
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- Help (13 members)
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- Hit2key (2 members)
- Holdery (1 member)
- Horatsuki (84 members)
- Hub Worlds (110 members)
- Hubster (2 members)
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- HyperGanesh (2 members)
- INT (8 members)
- If (3 members)
- If Guides (2 members)
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- If Nexus Worlds (3 members)
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- Immuno (3 members)
- Imported vocabulary (8 members)
- In Development (763 members)
- Infobox templates (12 members)
- Infoboxes with missing header styling (100 members)
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- Jaies (1 member)
- Jared (6 members)
- Jekyle (8 members)
- Jetrotal (1 member)
- John Ruiz (3 members)
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- KKO (1 member)
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- Kappa (59 members)
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- Kong (15 members)
- Kontentsu (270 members)
- Kubotsuki's Nexus Worlds (0 members)
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- Kubotsuki BGM (1 member)
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