title: In what standard is specified that elements with an id also get a global variable?
body: <p>I've noticed this a really long time ago, but I never found any information as to why this is supported by browsers in the first place.</p>
  
  <p>In every major browser, it is possible to refer to elements on the page by using their id as a global variable. <strong><a href="http://jsfiddle.net/SRCGU/" rel="nofollow">This fiddle</a></strong> shows an example of how it works. You can also try this out yourself (on this page) by just opening your console and pasting <code>footer</code> in it (which will return the <code>&lt;div id="footer"&gt;</code> on this page), or if you want to try it on a browser without console, just run <code>javascript:alert(footer)</code> from your url bar, which should alert "[object HTMLDivElement]" or something similar.</p>
  
  <p>I've tested this in Chrome, Firefox, Opera and even Internet Explorer, and in each of those browsers it seems to work. After searching for any standards about it though, I couldn't find anything.</p>
  
  <p>My question is, why does this work in every single browser, and is this part of any standards? Or is this just core JavaScript?</p>