title: Why does it work: background-position: top right -200px
body: <p>I'm trying to use a single image as background in a <em>fluid layout / responsive design</em> to create a <em>fake sidebar column</em>.</p>
  
  <p>Although the code in the title works just fine in Chrome (other browsers yet untested), I don't understand why. The <a href="http://www.w3schools.com/cssref/pr_background-position.asp" rel="nofollow">W3Schools</a> do not document a use of 3 "parameters". (A German site served as reference at first, but I needed an English reference for this question. That's the first I came up with.)</p>
  
  <p>I'm fine with the code working as long as it is cross-browser. I was going to test browser compatibility only once I'm satisfied with the design in Chrome.</p>
  
  <p>However, when I tried to employ something like:</p>
  
  <pre><code>background-position: -200px right -200px;
  </code></pre>
  
  <p>and tried different variations, it just failed.</p>
  
  <p><strong>Question:</strong> I couldn't find any documentation on this markup in the first place... could this be a bug or is there a valid explanation? If it is valid, could somebody explain to me how I could go about this properly?</p>