title: What does "OPT PSEUDOSECTION" mean in dig report?
body: <p>Take Facebook as an example, I found <code>OPT PSEUDOSECTION</code> doesn't exist in the first query request, but exist in the second try.</p>
  
  <p>What does <code>OPT PSEUDOSECTION</code> mean?</p>
  
  <p>Why it doesn't exist in the first try?</p>
  
  <p><a href="https://i.stack.imgur.com/uAqLT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uAqLT.png" alt="enter image description here"></a></p>