title: Behaviour of <link rel=alternate> in browsers
body: <p>I am a bit confused about the behavior of <code>&lt;link rel="alternate" ...&gt;</code> in browsers and i am looking for some clarification. Let's use the following code for illustration:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
      &lt;head&gt;
          &lt;link rel="stylesheet" href="a.css" type="text/css" 
                title="Main Stylesheet"&gt;
          &lt;link rel="alternate stylesheet" href="b.css" type="text/css" 
                title="Alternative Stylesheet"&gt;
          &lt;link rel="alternate" href="fr.pdf" hreflang="fr" type="application/pdf" 
                title="Alternative document in French"&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>When this code runs in a modern browser (e.g. Firefox v27.01), the browser parses the above HTML document and then downloads the stylesheets, a.css and b.css. The former is used to apply the style to the document. However, b.css is available through the 'View > Page Style' menu of the said browser. So, clearly the parser in Firefox is able to recognize the "alternative" stylesheet and in this case decided to download it. </p>
  
  <p>One can read at <a href="http://www.w3.org/TR/html5/links.html#rel-alternate" rel="noreferrer">W3C > HTML5 > 4.8.4.1</a> that the outcome of parsing those <code>&lt;link&gt;</code>s are <strong>basically</strong> hyperlinks referencing the respective document. In the case of stylesheet, the browser is smart enough to download it as well. But, for the other alternate document (fr.pdf) in our example, it looks like Firefox does not download it and if it links it, it is not visible anywhere. I tested in Chrome (v.33.0.1750.117), Opera (v.19.0.1326.63), IE (v.10.0.9200.16798) and could observe same thing (i.e. no visible artifact that the fr.pdf has been linked). So, as all those modern browsers behave like this, it looks like I have misunderstood the meaning of "alternate" relationships:) Would someone have an explanation for me of how they are intended to be used? My belief is that in a RESTful manner, user-agents should be able to (hyper)link all the <code>&lt;link&gt;</code>s in order to navigate that web.</p>
  
  <p>Thanks in advance. </p>