title: How to hide element on small screens with Bootstrap 4 Beta
body: <p>I just moved from bootstrap 4 alpha to beta, but I can't figure out how to hide an element on a small screen now. In the alpha this was "hidden-md-up" and "hidden-sm-down" which worked beautifully. "hidden-md-up" is now "d-md-none", but the other one I can't get to work</p>
  
  <pre><code>&lt;div class="d-md-block d-xs-none d-sm-none"&gt;Show on large screen only - NOT working for me&lt;/div&gt;
  &lt;div class="d-md-none"&gt;Show on small screen only&lt;/div&gt;
  </code></pre>
  
  <p>Any ideas?</p>