title: Is HTML case sensitive?
body: <p>Is HTML case sensitive?</p>
  
  <p>In an example I'm working with it says:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  </code></pre>
  
  <p>Would <code>&lt;!doctype html&gt;</code> or <code>&lt;!DocType Html&gt;</code> work differently (or not at all)?</p>