The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Telegram Group (1 member)
- Template documentation pages (1 member)
- Templates (1 member)
- Templates using TemplateData (1 member)
- Terrorism (1 member)
- The Compatible Left (11 members)
- Thematic maps (2 members)
- Theologians (2 members)
- Theories of history (1 member)
- Theory (essays) (1 member)
- Think tanks (5 members)
- Time zone maps (1 member)
- Timelines (1 member)
- To-do lists (2 members)
- Trade unionists (1 member)
- Trade unions (6 members)
- Trade unions by country (1 member)
- Trade unions in the United States (6 members)
- Trans comrades (0 members)
- Transgender Warriors (0 members)