anchor.diff:  </blockquote>
   ----
   
  -==== Sections
  -
  -*HTML element*: <section>
  -
  -*Special semantics*: class="sect1", class="sect2", class="sect3", class="sect4", class="sect5"
  -
  -*Note*: EPUB 3 Structural Semantic Vocabulary only has the term "division" for sections, and has no semantics for different section levels, so the above semantics are pulled directly from DocBook (operating on the assumption that semantics for section level are valuable in CSS, such that we don't need to write selectors like:
  -
  -----
  -section section section section { font-size: 50% }
  -----
  -
  -*Note 2*: Proposed use of HTML heading elements for sections is as follows:
  -
  -----
  -sect1 -> h1
  -sect2 -> h2
  -sect3 -> h3
  -sect4 -> h4
  -sect5 -> h5
  -----
  -
  -*Note 3*: Given the current state of EPUB 3 support, we will likely need to transform back to <div> in EPUB output order to ensure backward compatibility in EPUB 2 readers
  -
  -*Example*:
  -
  -----
  -<section class="sect1">
  -  <h1>A-Head</h1>
  -  <p>If you httpparty, you must party hard</p>
  -  <!-- Some more paragraphs -->
  -  <section class="sect2">
  -    <h2>B-Head</h2>
  -    <p>What's the frequency, Kenneth?</p>
  -    <!-- And so on... -->
  -  </section>
  -</section>
  -----
  -
   ==== Headings
   
  -
  -*HTML element*: <h1>, <h2>, <h3>, <h4>, <h5>, <h6>
  -
  -*Special semantics*: class="title"
  -
  -*Note*: In DocBook, <title> is used for all heading titles, regardless of "level", and context is used to determine formatting/styling. In HTML, best practice suggests that we associate each heading with a level from <h1> to <h6> that roughly indicates its rank. Here are my proposed mappings for each section type:
  +*HTML elements*: <h1>, <h2>, <h3>, <h4>, <h5>, or <h6>
  +
  +*Content Model*: text and/or zero or more Inline elements
  +
  +*Notes*: Many main book components (e.g., chapters, parts, appendixes) require headings. The appropriate
  +element from <h1>-<h6> is outlined below, as well as in the corresponding documentation for these
  +components:
   
   ----
   book title -> h1
  
positive.code: 
  ==== Video
  
  
  *HTML element*: <video>
  
  *Note*: Should include a fallback image via the +poster+ attribute and/or a link to the video online.
  
  *Example*:
  
  ----
  <video id="asteroids_video" width="480" height="270" controls="controls" poster="images/fallback_image.png">
  
negative.code: == HTMLBook Specification: Working Draft 19 April 2013
  
  Requirements for HTML5 elements in the HTMLBook specification are below. Special semantic inflections for +class+ attributes, unless otherwise noted, come from http://idpf.org/epub/vocab/structure/[EPUB 3 Structural Semantics Vocabulary]
  
  