I never said don't use ad_page_contract for documentation purposes. But it sounds to me like you have a page which is designed to be accessed normally, and then you decide to include it in some other page. _If_ it is an include, write it like one, in other words, write a wrapper around the include. Now you have provided documentation on how to include the tcl/adp pair in other templates.
It might also be nice in this case to pass in the .adp template that should be used like:
<include src="myfile" var="val" template="mytemplate" >
# then in the include:
ad_return_template $template
Now everyone knows they can include 'myfile', and they can use their own template on top of that!
