The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Sports (1 member)
- StarDict (1 member)
- Statistics (1 member)
- Stichting Studiebegeleiding Leiden (SSL) (1 member)
- Stock market (1 member)
- Swedish (1 member)
- TT-Software (1 member)
- TU/e (1 member)
- TU Delft (1 member)
- Tag cloud (1 member)
- Tags (1 member)
- Talon (1 member)
- Tax (5 members)
- Technical (25 members)
- Tenders (6 members)
- Term: G (0 members)
- TermCoord (1 member)
- TermFolders 2.0 (1 member)
- Termania (1 member)
- Terms (927 members)
- Terms: 0-9 (0 members)
- Terms: A (4 members)
- Terms: B (2 members)
- Terms: C (1 member)
- Terms: D (4 members)
- Terms: E (3 members)
- Terms: F (1 member)
- Terms: G (3 members)
- Terms: H (2 members)
- Terms: I (2 members)
- Terms: K (3 members)
- Terms: L (1 member)
- Terms: N (1 member)
- Terms: O (4 members)
- Terms: P (3 members)
- Terms: Q (3 members)
- Terms: R (3 members)
- Terms: S (9 members)
- Terms: T (1 member)
- Terms: U (14 members)
- Terms: V (3 members)
- Terms: W (2 members)
- Terms: X (1 member)
- Textielstad.nl (1 member)
- Textile (26 members)
- Textiles (1 member)
- Tilburg University (1 member)
- Time tracking software (1 member)
- Titles: 0-9 (0 members)
- Titles: A (0 members)