Template:Documentation subpage/doc

Usage
OR

This template should be placed at the top of "/doc" pages. It changes output depending on where it is viewed:
 * On a "/doc" page, it displays a box explaining template documentation and links to the template page.
 * On other pages (ie, pages transcluding the "/doc" page), it notes that the documentation is transcluded from a subpage.

Functions
In addition to the output message, the template categorizes pages to Category:Template documentation, Category:User documentation, or similar (named after the subject space), but only for documentation pages in namespaces with the subpage feature. It defaults the sort key to the page name without namespace (ie, "Foo" on "Template:Foo", so it would be sorted in categories under 'F').