title: Error by execution varnishtop with some parameters
body: <p>I'm trying to debug my varnish configuration, but when I execute </p>
  
  <pre><code>varnishtop -i TxUrl 
  </code></pre>
  
  <p>I get this error: </p>
  
  <pre><code>-i: "RxUrl" matches zero tags
  </code></pre>
  
  <p>Any idea why?</p>