title: Reliability of PHP'S $_SERVER['REMOTE_ADDR']
body: <p>I'm building a site that is designed to be administered from localhost, but contains pages that expose data to internet or local network users. Can I rely on PHP's <strong>$_SERVER['REMOTE_ADDR']</strong> as a secure/reliable way of identifying the user as localhost?
  Thanks!</p>
  
  <p><strong>Edit:</strong>
  To clarify, I am only concerned with determining whether or not the request originates from localhost (perhaps there is a better way).</p>