title: What is the "#fbml=1" doing in <script src="http://connect.facebook.net/en_US/all.js#xfbml=1"> ? URLs don't have hash but without it, it won't work
body: <p>What is the <code>#fbml=1</code> doing in <code>&lt;script src="http://connect.facebook.net/en_US/all.js#xfbml=1"&gt;</code> ?  (this is the official Facebook Like button code obtained from <a href="http://developers.facebook.com/docs/reference/plugins/like/" rel="nofollow">http://developers.facebook.com/docs/reference/plugins/like/</a> )</p>
  
  <p>Also, in Fiddler, I see it simply doing a </p>
  
  <pre><code>GET /en_US/all.js HTTP/1.1
  </code></pre>
  
  <p>But try to remove <code>#fbml=1</code>, and the page won't show the Facebook Like button.  What is the mechanism going on here?</p>