title: How to show unread/read status of forum post's like vbulletin, phpbb, others?
body: <p>This is the million dollar question, I see it time and time again on here and other php coding related sites and forums but I have NEVER seen an answer to it.  </p>
  
  <p>So I started digging in and studying how some of the big high traffic forums accomplish this feature of showing you which threads have new unread posts in them and it appears that they store the thread ID number into a user cookie.  So there would be a cookie with a thread ID of every thread you have read within a certain amount of time.  Or something similar to this.  </p>
  
  <p>I then read on here that cookies can only store X amount of characters, so I am wanting to know how much data can be stored in a cookie?  If I have a 5-6 character ID number, how many could I fit into a cookie?</p>