In PHP what does |= mean, That is pipe equals (not exclamation)
<p>I just found this in some code and I can't find anything on the web or php manual. Most likely since its an irregular character.</p>

<p>Here is one of the lines that uses it.</p>

<pre><code>$showPlayer |= isset($params['node']) &amp;&amp; $params['node'];
</code></pre>
