title: How to specify a thumbnail when sharing to Facebook?
body: <p>I ave embedded youtube video on my CodeIgniter page, i'm using official youtube embedding code: </p>
  
  <pre><code>&lt;iframe width="560" height="315" src="http://www.youtube.com/embed/msHFJhMqaKI" frameborder="0" allowfullscreen=""&gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>But when I try to share my page into facebook, i have no thumbnail, is there a tag or something what can help me with sign my video as future facebook thumbnail?</p>