title: How can i set keywords or (similar information) per page on pdf?
body: <p>i have a pdf it has almost 300-400 pages.I want to set information about per page.</p>
  
  <p>Ex : </p>
  
  <pre><code>(Information will be hidden)
  
  For page 4 = Information : history books
  For page 5 = Information : history books
  For page 6 = Information : history books
  
  For page 7 = Information : biology books
  For page 8 = Information : biology books
  For page 9 = Information : biology books
  
  .
  .
  .
  </code></pre>
  
  <p>And then i can extract pages easyly.</p>
  
  <p>thx for ur helps</p>