anchor.diff:  let title      = tag "title"
   
   // Content sectioning
  +let blockquote = tag "blockquote"
   let body       = tag "body"
   let address    = tag "address"
   let article    = tag "article"
  
positive.code:     let _hreflang           = attr "hreflang"
      let _httpEquiv          = attr "http-equiv"
      let _id                 = attr "id"
      let _keytype            = attr "keytype"
      let _kind               = attr "kind"
      let _label              = attr "label"
  
negative.code:     let _readonly           = flag "readonly"
      let _required           = flag "required"
      let _reversed           = flag "reversed"
      let _scoped             = flag "scoped"
      let _selected           = flag "selected"
      let _typemustmatch      = flag "typemustmatch"
  
  