title: How reliable is $_SERVER['REQUEST_URI'] at capturing query strings?
body: <p>From what I've read, it seems that <code>$_SERVER['REQUEST_URI']</code> won't <em>always</em> return query strings properly, but does anyone have a good sense of what the success rate is? Will it work in the majority of cases for the average client?</p>
  
  <p>What, if anything, would cause <code>REQUEST_URI</code> to not be populated or not include the query string?</p>