title: Label and placeholder accessibility
body: <p>I'm trying to find out if markup looks something like:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;label for="cc"&gt;Credit card&lt;/label&gt;
  &lt;input type="text" placeholder="Credit card" id="cc"&gt;
  </code></pre>
  
  <p>Is there a scenario where "Credit card" will be announced twice by the screen reader? </p>
  
  <p>I understand that the behavior might be different depending on the combination of browsers/screen readers, so I wonder if the general suggestion is to use only the <code>label</code> and to avoid duplication of the same text in <code>placeholder</code>.</p>