The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Album articles lacking alt text for covers (3 members)
- Album chart usages for Billboard200 (2 members)
- Album chart usages for Finland (1 member)
- Album chart usages for Sweden (1 member)
- Album chart usages for UK (1 member)
- AllMusic template missing ID and not in Wikidata (1 member)
- All articles with dead external links (1 member)
- All pages needing cleanup (1 member)
- All redirect categories (3 members)
- Andrew W.K. albums (4 members)
- Andrew W.K. songs (1 member)
- Article message templates (1 member)
- Article message templates with missing parameters (1 member)
- Articles with dead external links from July 2021 (1 member)
- Articles with hAudio microformats (3 members)
- Articles with hCards (1 member)
- Articles with invalid date parameter in template (1 member)
- Articles with permanently dead external links (1 member)
- Articles with short description (4 members)
- CatAutoTOC generates no TOC (2 members)
- CatAutoTOC on pages where PAGESINCATEGORY returns zero (2 members)
- Commons category link is the pagename (1 member)
- Disambiguation and redirection templates (1 member)
- Documentation header templates (1 member)
- Documentation see also templates (1 member)
- Encyclopedia external link templates (1 member)
- Hatnote templates (1 member)
- Hidden categories (3 members)
- Internal template-link templates (13 members)
- Interviews (2 members)
- Lore (3 members)
- Lua-based templates (14 members)
- Metacritic ID not in Wikidata (1 member)
- Miscellaneous redirects (16 members)
- Music infobox templates (1 member)
- Music infoboxes with Module:String errors (2 members)
- Navboxes using background colours (3 members)
- Navigational boxes without horizontal lists (1 member)
- Official website missing URL (1 member)
- Pages used in system messages needing protection (1 member)
- Pages using Timeline (1 member)
- Pages using duplicate arguments in template calls (18 members)
- Pages using infobox artist discography with unknown parameters (1 member)
- Pages using infoboxes with thumbnail images (1 member)
- Pages using xtag template with unsupported tag name (1 member)
- Pages with TemplateStyles errors (2 members)
- Pages with broken file links (20 members)
- Pages with reference errors (2 members)
- Pages with script errors (22 members)
- Pages with template loops (2 members)
- Philosophy external link templates (1 member)
- Redirect category shell without parameters (16 members)
- Redirect formatting templates (1 member)
- Redirect tracking categories (3 members)
- Redirects from alternative names (3 members)
- Redirects from high-use templates (3 members)
- Redirects from incorrect names (1 member)
- Redirects from long names (2 members)
- Redirects from merges (3 members)
- Redirects from modifications (4 members)
- Redirects from moves (38 members)
- Redirects to embedded anchors (2 members)
- Redirects to redirect templates (6 members)
- Redirects to templates (1 member)
- Semantic markup templates (0 members)
- Short description with empty Wikidata description (4 members)
- Side Projects (1 member)
- Spam (7 members)
- Template:Template category with no topic or description (1 member)
- Template documentation (1 member)
- Template documentation pages (6 members)
- Templates needing substitution checking (1 member)
- Templates using TemplateData (4 members)
- United States punk rock group navigational boxes (1 member)
- User soft redirects (3 members)
- Webarchive template wayback links (1 member)
- Wikipedia CatAutoTOC (2 members)
- Wikipedia extended-protected redirects (3 members)
- Wikipedia fully protected redirects (3 members)
- Wikipedia interwiki soft redirects (3 members)
- Wikipedia non-empty soft redirected categories (3 members)
- Wikipedia pages with incorrect protection templates (28 members)
- Wikipedia protected soft redirects (3 members)
- Wikipedia redirects (1 member)
- Wikipedia semi-protected redirects (3 members)
- Wikipedia soft redirected categories (3 members)
- Wikipedia soft redirected project pages (3 members)
- Wikipedia soft redirected talk pages (3 members)
- Wikipedia soft redirected templates (3 members)
- Wikipedia soft redirects (3 members)
- Wikipedia soft redirects to nonexistent targets (3 members)
- Wikipedia template-protected redirects (3 members)
- Wikipedia template categories (1 member)
- Wikipedia template parameter issues (1 member)
- Wikipedia transclusionless templates (3 members)
- Wikitext typing-aid templates (11 members)