title: What do margin:5px 0; and margin:5px 0 0; mean?
body: <p>Does <code>margin:5px 0;</code> mean <code>margin:5px 0 0 0;</code> or <code>margin:5px 0 5px 0;</code>?</p>
  
  <p>Does <code>margin:5px 0 0;</code> mean <code>margin:5px 0 0 0;</code>?</p>
  
  <p>Same for padding of course.</p>
  
  <p>Also, is it consistent across all browsers (including IE6)?</p>