title: Who Add "_" Single Underscore Query Parameter?
body: <p>I have a PHP server running on Apache, I get lots of request looks like this,</p>
  
  <pre><code>10.1.1.211 - - [02/Sep/2010:16:14:31 -0400] "GET /request?_=1283458471913&amp;action=get_list HTTP/1.1" 200 547 0 "http://www.example.com/request" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 (.NET CLR 3.5.30729)" 28632 15602
  </code></pre>
  
  <p>The _ parameter is mysteriously added to the request. I am trying to find out who is doing that.</p>
  
  <p>There is a NetScaler running in front of Apache.</p>