title: Using <link> where 'rel' is not 'stylesheet'
body: <p>Under what circumstances might one use a <code>&lt;link&gt;</code> element where <code>rel</code> is something <em>other</em> than <code>stylesheet</code>?  HTML5 supports quite a few other <code>rel</code> values on <code>link</code> elements, including</p>
  
  <ul>
  <li><code>archives</code></li>
  <li><code>author</code></li>
  <li><code>first</code>, <code>last</code>, <code>next</code>, <code>prev</code></li>
  <li><code>help</code></li>
  <li><code>index</code>, <code>up</code></li>
  <li>More at listed at <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Link_types" rel="nofollow">https://developer.mozilla.org/en-US/docs/Web/HTML/Link_types</a>.</li>
  </ul>
  
  <p>But <code>link</code> elements go in the <code>head</code> section; they don't correspond to page contents.  What then is the point of linking to a bunch of semantically-interesting documents if the user has no way of opening the link?  </p>