title: How do you determine whether a CSS property requires browser specific prefixes?
body: <p>I recently looked at the following question:</p>
  
  <p><a href="https://stackoverflow.com/questions/826782/css-rule-to-disable-text-selection-highlighting">How to disable text selection highlighting using CSS?</a></p>
  
  <p>Which nicely provided the answer to the immediate CSS problem I was facing. However, it made me wonder, how do you determine when it is safe to drop all the browser specific prefixes for CSS properties?</p>
  
  <p>I know how the mechanics of this work, older browsers which require a prefix will of course always need a prefix, so I suppose the answer really depends on the browser usage statistics. </p>
  
  <p>Is there a decent, simple, source of reference that can be used to determine whether all these prefixes are really required for a CSS property, e.g. if I use the <code>user-select</code> property without prefixes, I can guarantee 95% of browsers will interprit this correctly.</p>