The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Transhumanism (1 member)
- Trotskyism (9 members)
- Trotskyist organisations (8 members)
- Trotskyists (3 members)
- Trumpism (1 member)
- U-S-U work (1 member)
- U.S government collaborators (1 member)
- UN resolutions (3 members)
- US-backed coups (1 member)
- USA News outlets (2 members)
- USA states (14 members)
- USSR (0 members)
- US News Outlets (1 member)
- US politician memes (4 members)
- UT Austin (1 member)
- Ukrainian collaborators with Nazi Germany (1 member)
- Ultra-left YouTube channels (2 members)
- Unfinished transcripts (2 members)
- Unfree labor (1 member)
- Union of Soviet Socialist Republics (6 members)