anchor.diff:  
   *HTML element*: +<aside>+
   
  -*Attribute requirements*: +class="sidebar"+
  +*Attribute requirements*: +data-type="sidebar"+
   
   *Content model*: Zero or one +<h5>+ element that contains the sidebar title); then zero or more Block elements
   
   *Example*:
   
   ----
  -<aside class="sidebar">
  +<aside data-type="sidebar">
     <h5>Amusing Digression</h5>
     <p>Did you know that in Boston, they call it "soda", and in Chicago, they call it "pop"?</p>
   </aside>
  
positive.code: "sect5" -> h5
  ----
  
  The heading is followed by zero or more subheading elements whose hierarchy level is one lower than the main heading (e.g., +<h2>+ for a ++sect1++), folloed by zero or more Block elements, followed by zero or more +<section>+ elements with a class value one level lower in the hierarchy, as long as the parent section is a "sect4" or higher (e.g., +<section class="sect4">+ nested in +<section class="sect3">+)
  
  *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... -->
  
negative.code: 
  *HTML element*: +<section>+
  
  *Attribute requirements*: +data-type="bibliography"+
  
  *Content model*: First child must be +<h1>+ that contains bibliography title; then zero or more +<h2>+ elements for subtitle content; then zero or more Block Elements; then zero or more Sect1 children (+<section data-type="sect1">+)
  
  *Example*
  
  ----
  <section data-type="bibliography">
    <h1>Bibliography Title</h1>
    <p>Bibliography content</p>
    <section data-type="sect1">
      <!-- Section content here... -->
    </section>
  </section>
  