title: "CAUTION: provisional headers are shown" in Chrome debugger
body: <p>I noticed a strange caution message when looking at downloaded resources using Google chrome inspector (<kbd>F12</kbd>):</p>
  
  <blockquote>
    <p>Caution provisional headers are shown</p>
  </blockquote>
  
  <p><img src="https://i.stack.imgur.com/PrUY4.jpg" alt="enter image description here"></p>
  
  <p>I found something possibly relevant, <a href="https://code.google.com/p/chromium/issues/detail?id=294891" rel="noreferrer">Network Panel: add caution about provisional request headers</a>, but I could not fully understand it. Related questions can be found <a href="https://stackoverflow.com/questions/20521755/chrome-block-requests">Chrome block requests</a> as well as <a href="https://stackoverflow.com/questions/21035814/xmlhttprequest-cannot-load-unloaded-resources-show-caution-provisional-headers">XMLHttpRequest cannot load. Unloaded resources show caution: Provisional headers are shown</a>. </p>
  
  <p>Similar to the <a href="https://stackoverflow.com/questions/20521755/chrome-block-requests">first question</a>, my resource was blocked, but later automatically loaded the same resource. Unlike the <a href="https://stackoverflow.com/questions/21035814/xmlhttprequest-cannot-load-unloaded-resources-show-caution-provisional-headers">second question</a>, I don't want to fix anything; I want to know what this message means and why I received it.</p>