title: What is the proper way to check and uncheck a checkbox in HTML5?
body: <p>Looked at the HTML spec, but couldn't make heads or tails of it: <a href="http://www.w3.org/TR/html5/the-input-element.html#attr-input-checked" rel="noreferrer">http://www.w3.org/TR/html5/the-input-element.html#attr-input-checked</a></p>
  
  <p>What is the correct way to check a checkbox in HTML (not dynamically)?</p>
  
  <pre><code>checked="true"
  checked="checked"
  </code></pre>
  
  <p>What is the correct way to <strong><em>uncheck</em></strong> a checkbox?</p>
  
  <pre><code>&lt;input type="checkbox" /&gt; with no checked attribute
  checked="false"
  checked="none"
  </code></pre>
  
  <p>Where to check the HTML specification to check/uncheck a checkbox?</p>