title: What is utmu parameter in google analytics __utm.gif request?
body: <p>I am trying to make the google analytic __utm.gif request using php. I have broken all the variables and the only one which I don't know about is <strong>utmu</strong> parameter. It is not documented anywhere.</p>
  
  <p>When I see a pageview tracking request it is appended to the end of request as <code>&amp;utmu=qB~</code>
  While doing ecommerce tracking it is appended as <code>&amp;utmu=qBAL~</code></p>
  
  <p>Please help me with this.</p>