The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Windows CE (1 member)
- Windows Phone games (1 member)
- Windows video games by name (2 members)
- Xbox 360 games by name (1 member)
- Xbox One games by name (1 member)
- ZVProject Tree of Life (1 member)
- Zenniverse Media biology maintenance (2 members)
- Zenniverse Media category maintenance by used template (1 member)
- Zenniverse Media geocoding (1 member)
- Zenniverse Media maintenance (2 members)
- Zenniverse Media maintenance content (1 member)
- Zoom (1 member)