What is the best way to track internal referrals with php?
<p><code>$_SERVER['HTTP_REFERER']</code> seems to be full of holes.</p>

<p>Tracking through the url will not be possible for this particular application.</p>

<p>I have a 301 Redirect to take into account also. </p>

<p>I will check <code>$_SERVER['HTTP_REFERER']</code>, but what is a good second method to check what page on my site the user came from?</p>

<p>Is it as simple as setting up a session variable? I am looking for specific examples that will help augment <code>$_SERVER['HTTP_REFERER']</code>.</p>
