title: Preserve dynamically changed HTML on back button
body: <p>It's amazing, I constantly see this working in other sites but never in sites that I'm working on.</p>
  
  <p>I'm bringing in new content with ajax, I know about history.js and the History API, I do not want to change the URL, just have the browser cache the new HTML content so when a user leaves the page and comes back using the back button, it still has the updated HTML.</p>
  
  <p>I see this working all the time in other sites without URL changes or using the hash #.<br>
  Is there a trick to get it to work or is it randomly decided by the browser?<br>
  If I don't want to use the URL to have this information, is there an easy alternative?</p>