title: Can an AJAX request utilize link prefetching?
body: <p>As most of you know, <a href="http://en.wikipedia.org/wiki/HTML5" rel="noreferrer">HTML5</a> introduced a standardized browser mechanism called <a href="http://en.wikipedia.org/wiki/Link_prefetching" rel="noreferrer">link prefetching</a>, one that allows preloading the content of select URLs in the background, if the browser determines there is no network activity. It's used by adding the following to the head:</p>
  
  <pre><code>&lt;link rel="prefetch" href="http://www.example.com/"&gt;
  </code></pre>
  
  <p>I'm curious if this mechanism works reliably for <a href="https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest" rel="noreferrer">XMLHttpRequest</a> as well -- in the sense that if I specify a link prefetch, and then sometime later on that very same page initiate an AJAX request, would the XHR be a <a href="http://en.wikipedia.org/wiki/Byte_serving" rel="noreferrer">HTTP byte-range request</a>, or ask for the entire page, effectively ignoring a partially preloaded page?</p>
  
  <p>In english: would the AJAX request benefit from the preloaded or partially preloaded content as well?</p>