Prerender spec

Hi,
It has been on our charter to write a specification for "prerender".

Please check:
http://www.w3.org/html/wg/drafts/html/master/single-page.html#link-type-prefetch

It seems logical to specify the behavior of <link rel="prerender"> in this
document.

Do folks agree? Or should there be a separate document?

Of course, we would need the editors of the HTML5.1 spec to agree that this
belongs in their specification.

My suggestion for the text is as follows. Any comments?
4.13.5.10 Link type "prerender"

The prerender keyword may be used with a
link<http://www.w3.org/html/wg/drafts/html/master/single-page.html#the-link-element>
 element. This keyword creates an external resource
link<http://www.w3.org/html/wg/drafts/html/master/single-page.html#external-resource-link>
.

The prerender keyword indicates that preemptively fetching and loading the
specified resource in a hidden top-level browsing
context<http://www.w3.org/html/wg/drafts/html/master/single-page.html#top-level-browsing-context>is
likely to be beneficial, as it is highly likely that the user will
navigate to this resource. If the resource is navigated to, the user agent
may replace the current browsing context with the one it loaded the
specified resource in.

The user agent may discard the browsing context corresponding to the
prerendered resource if any of the following is true:


   - If the resource is not navigated to within a reasonable amount of time.
   - If the user navigates to some other resource from the current browsing
   context.
   - If the link element is removed from the document.

There is no default type for resources given by the prerender keyword.