title: Proper semantic representation for addendum to, or description of a header
body: <p>Say I have content in the form</p>
  
  <pre><code>&lt;h2&gt;George Epworth&lt;/h2&gt;
  &lt;h3&gt;Director&lt;/h3&gt;
  &lt;p&gt;Content Content Content&lt;/p&gt;
  </code></pre>
  
  <p>There I've represented the descriptive part of the h2 as an h3, but it's really more part of the h2 isn't it? the h3 here doesn't exist on its own and is dependant on the h2. Just trying to think of the most flexible way to define this element...</p>