anchor.diff:    h3 Modifications applied to W3C HTML 5.1
     ul
       li Replace “’” with “'”
  -    li Replace “Serializing” with “Serialising” in “The HTML syntax” and “The XHTML syntax”
  -    li Replace “Colors” with “Colours” in “Common infrastructure”
  -    li Replace “Plugin Content Handlers” with “Plugins” in “Common infrastructure”
  +    li Replace “behavior” with “behaviours”
  +    li Replace “Color” with “Colour” “excepting type=color”
  +    li Replace “Plugin Content Handlers” with “Plugins”
  +    li Replace “Serializing” with “Serialising”
  +    li Replace “Synchronizing” with “Synchronising”
       li Reorder “Links” in “The elements of HTML”
   
     h2 Q. Are HTMLs displayed in this site same as the specifications?
  
positive.code:     li Remove <code>a.self-link</code>
      li Remove <code>highlight</code> from <code>class</code> attribute
      li Remove <code>role</code> attribute (ex. <code>role=note</code>)
      li Remove “Allowed ARIA role attribute values:” and “Allowed ARIA state and property attributes:” (temporary)
  
negative.code:     li <code>ruby</code>
      li <code>cite</code>
      li <code>iframe[seamless]</code>
      li <code>xml:base</code>
      li Table sorting model
      li <code>input[type="datetime-local"]</code> and <code>input[type="datetime"]</code>
      li Canvas 2D Context
  