The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Talk message boxes (1 member)
- Talk namespace templates (1 member)
- Technic Stations (1 member)
- Template:Template category with no topic or description (1 member)
- Template documentation (1 member)
- Template documentation pages (225 members)
- Template metamodules (1 member)
- Template namespace templates (4 members)
- Template stylesheets (1 member)
- Templates (1 member)
- Templates generating hCards (1 member)
- Templates generating hCards and Geo (7 members)
- Templates that add a tracking category (13 members)
- Templates that generate named references (1 member)
- Templates that generate short descriptions (5 members)
- Templates using TemplateData (32 members)
- Templates using TemplateStyles (23 members)
- Templates using data from Wikidata (3 members)
- Templates with coordinates fields (7 members)
- Text-specific formatting and function templates (1 member)
- Tracking categories (2 members)
- Tracking templates (5 members)
- Train Line Proposals (1 member)
- Train Lines (5 members)
- Train lines operated by the NEG (1 member)
- Transport infobox templates (1 member)
- Transportation Locations (1 member)
- Transportation infrastructure operated by the NEG (2 members)
- Travelnet hubs (1 member)
- Tutorial (3 members)
- Tutorials (5 members)
- Typing-aid templates (2 members)
- Uncategorized Tutorials (3 members)
- Unicode character modules (1 member)
- Unicode data modules (8 members)
- Uses TemplateStyles templates with errors (1 member)
- Varieties of English templates (1 member)
- WikiProject Mountains templates (1 member)
- Wikipedia Portal templates (1 member)
- Wikipedia XHTML tag-replacing templates (3 members)
- Wikipedia formatting and function templates (1 member)
- Wikipedia infoboxes (1 member)
- Wikipedia magic word templates (1 member)
- Wikipedia metatemplates (2 members)
- Wikipedia multilingual support templates (2 members)
- Wikipedia non-diffusing parent categories (1 member)
- Wikipedia soft redirected templates (1 member)
- Wikipedia soft redirects (2 members)
- Wikipedia soft redirects to nonexistent targets (3 members)
- Wikipedia substituted templates (6 members)