title: html5 meta tag cache-control no longer valid?
body: <p>How do I define </p>
  
  <pre><code>&lt;meta http-equiv="cache-control" content="no-cache" /&gt;
  </code></pre>
  
  <p>in HTML5? It is no longer valid according to the W3C Validator and the <a href="http://www.w3.org/TR/html5/semantics.html#attr-meta-http-equiv" rel="noreferrer">documentation</a>.</p>