anchor.diff:  encode_1([Label|Labels], Acc) ->
       encode_1(Labels, lists:reverse(alabel(Label), [$.|Acc])).
   
  -
   check_nfc(Label) ->
     case characters_to_nfc_list(Label) of
       Label -> ok;
  
positive.code:         encode_1(Labels, [])
      end.
  
  to_ascii(Domain) -> encode(Domain, [uts46]).
  
  
  
negative.code:       ok
    end.
  
  check_label(Label) ->
    ok = check_nfc(Label),
    ok = check_hyphen(Label),
  