anchor.diff:      (q cite)
       (script type language src defer async charset language)
       (select name disabled form size multiple autofocus required)
  -    (source src type media)
  +    (source src srcset sizes type media)
       (style type media scoped)
       (table border)
       (td colspan rowspan
  
positive.code:      novalidate target autocomplete)
      (html manifest)
      (iframe src srcdoc name width height sandbox seamless)
      (img src alt height width usemap ismap border)
      (input name disabled form type maxlength readonly size value
       autocomplete autofocus list pattern required placeholder
       dirname checked multiple src height width
  
negative.code:     figcaption figure footer form head h1 h2 h3 h4 h5 h6 header
      hgroup hr html i iframe img input ins kbd keygen label legend li
      link main map mark menu meta meter nav noscript object ol
      optgroup option output p param picture pre progress q rp rt ruby s samp
      script section select small source span strong style sub summary
      sup table tbody td textarea tfoot th thead time title tr
      track u ul var video wbr))
  