anchor.diff:          false ->
               case Key of
                   <<"user-data">> ->
  -                    tag_lookup(JsonBody, Rest, [[] | Results]);
  +                    tag_lookup(JsonBody, Rest, [{struct, []} | Results]);
                   _ ->
                       {error, not_found}
               end
  
positive.code:             {<<"version">>, 1},
              {<<"urls">>, D#tagcontent.urls},
              {<<"last-modified">>, D#tagcontent.last_modified},
              {<<"user-data">>, D#tagcontent.user}
          ]})).
  
  -spec tag_lookup(any(), [binary()], [any()]) ->
  
negative.code:             case tag_lookup(Body,
                              [<<"id">>, <<"urls">>, <<"last-modified">>, <<"user-data">>],
                              []) of
                  {ok, [Id, Urls, LastModified, {struct, UserData}]} ->
                      {ok, #tagcontent{id = Id,
                                       last_modified = LastModified,
                                       urls = Urls,
  