anchor.diff:              li #[code mark] &mdash; relevance in a certain context
               li #[code u] &mdash; annotations
               li #[code small] &mdash; side comments
  -            li #[code s] &mdash; inaccurate text #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: a.Rf(rel="this" href="#fn-s")#rf-s 16]]
  +            li #[code s] &mdash; inaccurate text #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: +reference('s-transparent-content-model')]]
           section
             h3 Documentation and Edits
             ul
  -            li #[code ins] #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: a.Rf(rel="this" href="#fn-ins")#rf-ins 17]]
  -            li #[code del] #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: a.Rf(rel="this" href="#fn-del")#rf-del 18]]
  +            li #[code ins] #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: +reference('ins-transparent-content-model')]]
  +            li #[code del] #[small.o-Textbox.c-Label.c-Label--info Transparent Content Model #[sup: +reference('del-transparent-content-model')]]
               li #[code dfn]
               li #[code b] &mdash; keyword
               li #[code var]
  
positive.code:       section
          h2 Embedded Content
          ul
            li #[code img] #[small.o-Textbox.c-Label.c-Label--info Nothing Content Model #[sup: a.Rf(rel="this" href="#fn-img")#rf-img 25]]
        section
          h2 Forms
          ul
            li #[code input] #[small.o-Textbox.c-Label.c-Label--info Nothing Content Model #[sup: a.Rf(href="#fn-input")#rf-input 26]]
        section
          h2 Interactive Content
        footer
          ul.c-ListFootnotes
            li
              sup
                a.Fn(rel="this" href="#rf-a")#fn-a 15
                a.Fn(rel="this" href="#rf-s")#fn-s 16
                a.Fn(rel="this" href="#rf-ins")#fn-ins 17
                a.Fn(rel="this" href="#rf-del")#fn-del 18
              | An element with a #[dfn Transparent Content Model] may contain only content types
              |  matching the Content Model of the said element&rsquo;s parent.
            li
              sup
                a.Fn(rel="this" href="#rf-hn")#fn-hn 19
                a.Fn(rel="this" href="#rf-p")#fn-p 20
                a.Fn(rel="this" href="#rf-pre")#fn-pre 21
              | An element with a #[dfn Phrasing Content Model] may contain only phrasing content children.
            li
              sup
                a.Fn(rel="this" href="#rf-hr")#fn-hr 6
                a.Fn(rel="this" href="#rf-col")#fn-col 11
                a.Fn(rel="this" href="#rf-br")#fn-br 13
                a.Fn(rel="this" href="#rf-wbr")#fn-wbr 14
                a.Fn(rel="this" href="#rf-img")#fn-img 25
                a.Fn(rel="this" href="#rf-input")#fn-input 26
              | An element with an #[dfn Nothing Content Model] may contain no children. 
              small.
                Most elements with a Nothing Content Model are also #[dfn void elements], which
                have a start tag but no end tag.
            li
              sup
                a.Fn(rel="this" href="#rf-section")#fn-section 2
                a.Fn(rel="this" href="#rf-article")#fn-article 3
                a.Fn(rel="this" href="#rf-aside")#fn-aside 4
                a.Fn(rel="this" href="#rf-nav")#fn-nav 5
              | #[dfn Sectioning Content] adds to the Document Outline (#[abbr.c-Acro(title="document outline") DO]).
            li
              sup
                a.Fn(rel="this" href="#rf-body")#fn-body 1
                a.Fn(rel="this" href="#rf-figure")#fn-figure 7
                a.Fn(rel="this" href="#rf-blockquote")#fn-blockquote 8
                a.Fn(rel="this" href="#rf-td")#fn-td 12
              | #[dfn Sectioning Roots] have outlines, but they are encapsulated,
              |  hidden from the #[abbr.c-Acro(title="document outline") DO].
            li
              sup
                a.Fn(rel="this" href="#rf-li")#fn-li 9
                a.Fn(rel="this" href="#rf-dd")#fn-dd 10
              | The #[code li] and #[code dd] Elements seem like they should be Sectioning Roots
              |  but they are not! Do not contain sectioning content inside these Elements
              |  unless you want to change the #[abbr.c-Acro(title="document outline") DO]!
            li
              sup
                a.Fn(rel="this" href="#rf-address")#fn-address 22
                a.Fn(rel="this" href="#rf-dt")#fn-dt 23
                a.Fn(rel="this" href="#rf-th")#fn-th 24
              | The #[code address], #[code dt], and #[code th] elements may contain flow content except
              |  sectioning content, heading content, headers, and footers.
      script(src="../bower_components/jquery/dist/jquery.js")
  
negative.code:     meta(name="viewport" content="width=device-width, initial-scale=1")
      link(rel="stylesheet" href="../../styles/chharvey.css")
    body.o-GoldenContainer
      - var refs = []
      mixin reference(id)
        - refs.push(id)
        a.Rf(id='rf-'+id href='#fn-'+id)= refs.indexOf(id)+1
      mixin footnote(id)
        a.Fn(id='fn-'+id href='#rf-'+id)= refs.indexOf(id)+1
      main.o-GoldenContainer__Content.c-Document(data-status="draft" itemscope="" itemtype="https://schema.org/Article")
        header
          h1(itemprop="name headline") Notes on HTML Elements
  