Unless this category is identified as an infobox or ambox category, by default the only kind of templates within it should be navboxes (and/or occasionally less common template types).
Greek-letter indices
μ = stub; τ = template; ω = WikiProject
To include a template in this category, add <noinclude>[[Template:Template category|{{PAGENAME}}]]</noinclude> to the end of the template code, making sure it starts on the same line as the last character of the code.
Template documentation