The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Topics covered better by other wikis/es (10 members)
- Topics covered better by other wikis/fi (16 members)
- Topics covered better by other wikis/fr (18 members)
- Topics covered better by other wikis/ja (1 member)
- Topics covered better by other wikis/ko (2 members)
- Topics covered better by other wikis/pl (3 members)
- Topics covered better by other wikis/pt-br (20 members)
- Topics covered better by other wikis/ru (15 members)
- Tracking categories (2 members)
- Trademark images (1 member)
- Translating into (1 member)
- Translating into Chinese (Simplified) (5 members)
- Translating into Chinese (Traditional) (2 members)
- Translating into Czech (3 members)
- Translating into Danish (3 members)
- Translating into Finnish (2 members)
- Translating into French (6 members)
- Translating into German (1 member)
- Translating into Hungarian (1 member)
- Translating into Italian (1 member)
- Translating into Japanese (26 members)
- Translating into Korean (18 members)
- Translating into Norwegian (1 member)
- Translating into Polish (9 members)
- Translating into Portuguese (Brazil) (10 members)
- Translating into Russian (14 members)
- Translating into Spanish (4 members)
- Translating into Swedish (5 members)
- Translation progress (3 members)
- Translations needing updating (9 members)
- Translators (45 members)
- Turret images (14 members)
- Turret voice files (154 members)
- Turret voice files/de (133 members)
- Turret voice files/fr (144 members)
- Turret voice files/ru (155 members)
- Ukranians (2 members)
- Unreleased content (0 members)
- Untagged spoilers (1 member)
- Unused content images (17 members)
- User:ChickenNuggetMan2056/Portal 2 chambers (1 member)
- User:ChickenNuggetMan2056 Portal 2 chambers (1 member)
- User favorite cores (8 members)
- User favorite human (1 member)
- User images (240 members)
- Userbox templates (94 members)
- Users (40 members)
- Users from France (6 members)
- Users from Hong Kong (1 member)
- Users that has followed CDT (3 members)
- Valve (13 members)
- Valve/de (1 member)
- Valve/es (4 members)
- Valve/fi (8 members)
- Valve/fr (4 members)
- Valve/ko (2 members)
- Valve/pt-br (9 members)
- Valve/ru (5 members)
- Valve images (252 members)
- Videos (24 members)
- Videos/es (2 members)
- Videos/fi (25 members)
- Videos/fr (10 members)
- Videos/ja (3 members)
- Videos/pl (2 members)
- Videos/pt-br (14 members)
- Videos/ru (13 members)
- Voice actors (7 members)
- Voice actors/de (3 members)
- Voice actors/es (6 members)
- Voice actors/ru (5 members)
- Voice files (3,455 members)
- Voice files/de (2,638 members)
- Voice files/es (3,037 members)
- Voice files/fr (2,960 members)
- Voice files/ru (3,588 members)
- Voice lines (26 members)
- Voice lines/cs (3 members)
- Voice lines/da (2 members)
- Voice lines/de (8 members)
- Voice lines/es (10 members)
- Voice lines/fi (9 members)
- Voice lines/fr (10 members)
- Voice lines/ja (1 member)
- Voice lines/ko (3 members)
- Voice lines/pl (1 member)
- Voice lines/pt-br (7 members)
- Voice lines/ru (10 members)
- Voice lines/sv (1 member)
- Voice lines/zh-hant (4 members)
- Walkthrough images (82 members)
- Wheatley images (10 members)
- Wheatley players (8 members)
- Wheatley voice files (828 members)
- Wheatley voice files/de (821 members)
- Wheatley voice files/es (821 members)
- Wheatley voice files/fr (821 members)
- Wheatley voice files/ru (903 members)
- Wikipedia doc (0 members)
- Музыка (1 member)