The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Martial Arts (29 members)
- Mbox and messagebox templates (7 members)
- Medical Conditions (1 member)
- Missing or Dead (21 members)
- Missing or Destroyed (32 members)
- Modern Technology (3 members)
- Modules for general use (1 member)
- Modules subject to page protection (4 members)
- Modules that add a tracking category (2 members)
- Modules that check for strip markers (1 member)
- Music templates (1 member)
- Narcissism (0 members)
- Navboxes using background colours (3 members)
- Navigational boxes without horizontal lists (1 member)
- Needs Setting (2 members)
- Nibara Sector (6 members)
- Non-Player Characters (152 members)
- Non-subject-matter-related article-talk header templates (1 member)
- Notice and warning templates (2 members)
- Novelist navigational boxes (1 member)
- OOC (47 members)
- Omega Tal'us Sector (1 member)
- Onyx Actions (1 member)
- Onyx Characters (0 members)
- Onyx Non-Player Characters (2 members)
- Onyx Vessels and Facilities (4 members)
- Orders (9 members)
- Organizations (2 members)
- Pages generating RSS feeds (0 members)
- Pages monitored by Wikipedia bots (1 member)
- Pages related to the WikiProject meta banner (1 member)
- Pages used in system messages needing protection (3 members)
- Pages using deprecated source tags (3 members)
- Pages using duplicate arguments in template calls (8 members)
- Pages with Issues (0 members)
- Pages with broken file links (0 members)
- Pages with incorrectly transcluded templates (1 member)
- Pages with script errors (52 members)
- People (127 members)
- Personal life (0 members)
- Personality traits (1 member)
- Philosopher navigational boxes (2 members)
- Philosophy and thinking navigational boxes (3 members)
- Philosophy and thinking sidebar templates (3 members)
- Philosophy of life (1 member)
- Places (48 members)
- Planes of Existence (13 members)
- Played by Amis (3 members)
- Played by BROK3N (5 members)
- Played by Bucket (9 members)