The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- GGZ (1 member)
- GWIT (1 member)
- Gambling (1 member)
- Geoengineering (1 member)
- Geometry (1 member)
- Geotechniek (1 member)
- German (7 members)
- Glossaries (215 members)
- Glossary (1 member)
- GoldenDict (6 members)
- Golossaries (1 member)
- Grammar (3 members)
- H (1 member)
- HR (1 member)
- HVAC (2 members)
- Hazard and Precautionary Statements (1 member)
- Hemp (1 member)
- Herman Busser (1 member)
- Horses (1 member)
- Hospitals (1 member)
- Hotels (1 member)
- Huitenga (1 member)
- Hungarian (1 member)
- Hydraulic engineering (1 member)
- I (1 member)
- IATE (9 members)
- IEEE (1 member)
- IT (16 members)
- IVDNT (1 member)
- Ihagee (1 member)
- Index (5 members)
- Information Systems Audit and Control Association (1 member)
- Inheritance law (1 member)
- Insects (1 member)
- Instituut voor de Nederlandse Taal (1 member)
- Insurance (1 member)
- International Institute of Refrigeration (IIR) (1 member)
- International Monetary Fund (IMF) (1 member)
- International Translation Day (1 member)
- International Wadden Sea School (IWSS) (1 member)
- Internet (1 member)
- Internet Archive (1 member)
- Italian (4 members)
- J.A.M. Berkien (1 member)
- Jerzy Kazojć (1 member)
- John Hutchins (1 member)
- Joostdevree.nl (3 members)
- JurLex (1 member)
- Juremy.com (1 member)
- Juridisch-Economisch Lexicon (1 member)