anchor.diff:  
   *Special semantics*: class="programlisting" or class="screen"footnote:[From DocBook; EPUB 3 Structural Semantics Vocabulary has no semantics for code blocks)]
   
  +Also, data-language to indicate programming language, e.g., +data-language="python"+
  +
   *Note*: May not be worth supporting semantic distinction between "screen" and "programlisting", but I can see it being valuable, if we want distinct styling for command-line environments.
   
   *Example*:
  
positive.code: ----
  <pre class="programlisting">print "Hello World"</pre>
  ----
  
  ==== Ordered lists
  
  
negative.code: </audio>
  ----
  
  ==== Canvas
  
  *Legacy DB element*: No direct correlation 
  
  *New HTML element*: <canvas>
  
  *Note*: Should include a fallback link.
  
  *Examples*:
  
  ----
  <canvas id="canvas" width="400" height="400">
   Your browser does not support the HTML 5 Canvas. See the interactive example at http://example.com.
  </canvas>
  ----
  
  ==== General Interactive
  
  *Legacy DB element*: No direct correlation 
  