Categories & Templates
FYI, see the talk page of the Blogging Handbook about use of templates and categories. Unfortunately, I can't provide a direct link because it seems of a LQT bug that can't handle ampersands in the title of a thread post. In brief, there is no need for use of Template: at the start of a transclusion. Plus there is no need for the page name unless you're wanting to use parameters, in which it needs to be separated by a |. By removing the page names from your transclusions, all your pages for the Blogging Handbook would be automatically now categorised since I've inserted categories into the template.