If the Scribunto extension is installed, this page should be changed to the following format:

   Documentation text
   <includeonly>Categories for Module:Navbox</includeonly>
   <noinclude>Categories for this page</noinclude>

The /doc subpage of pages in the Module namespace are automatically transcluded by Scribunto. --Brian (talk) 00:55, 31 July 2014 (EDT)