Template:Documentation/doc

On template (or other) pages
This template displays a "(Namespace) documentation" box like the one you are seeing now. Place the following code on the template (or other) page, and edit the documentation page (click the "[edit]" link after you save) where you can put instructions, categories, et cetera. &lt;noinclude&gt;&lt;/noinclude&gt;

On documentation subpages
Please add the following code at the top of the subpage to put it in Category:Documentation subpages; this keeps it out of Special:Uncategorizedpages and links back to the main page. &lt;noinclude&gt;&lt;/noinclude&gt;

Typically documentation subpages are not also put in the categories in which the page the documentation refers to is put.

Explanation
Transcluding a template B on a page A adds to the of page A, which is the amount of text the server must process for transclusion to render the page. Content of template B that is discarded during this process due to noinclude tags, like documentation, adds to this include size of page A even though it doesn't appear on the page. Transcluding the documentation from a subpage C reduces this include size to the negligible number of bytes added by the characters on the template page itself, thus reducing server load.

Using a subpage also allows anyone to edit the documentation, categories, or interwiki links of a protected template.