anchor.diff:      m_to_list/2,
       m_value/2,
       url_for/1,
  -    language_url_for/2
  +    language_url_for/2,
  +    label/1
   ]).
   
   -include_lib("zotonic.hrl").
  
positive.code: m_find_value(url, #m{value = License}, _Context) ->
      url_for(License);
  m_find_value(language_url, #m{value = License}, Context) ->
      language_url_for(License, Context).
  
  m_to_list(_, _Context) ->
      [].
  
negative.code: url_for(_) ->
      undefined.
  
  label(<<"https://", Url/binary>>) ->
      label(<<"http://", Url/binary>>);
  label(<<"http://creativecommons.org/licenses/", Label/binary>>) ->
      label(Label);
  label(<<"by/", _Version/binary>>) ->
      <<"BY">>;
  label(<<"by-sa/", _Version/binary>>) ->
      <<"BY-SA">>;
  label(<<"by-nd/", _Version/binary>>) ->
      <<"BY-ND">>;
  label(<<"by-nc/", _Version/binary>>) ->
      <<"BY-NC">>;
  label(<<"by-nc-sa/", _Version/binary>>) ->
      <<"BY-NC-SA">>;
  label(<<"by-nc-nd/", _Version/binary>>) ->
      <<"BY-NC-ND">>;
  label(<<"http://creativecommons.org/publicdomain/zero/", _Version/binary>>) ->
      <<"CC0">>;
  label(<<"http://creativecommons.org/publicdomain/mark/", _Version/binary>>) ->
      <<"PD">>.
  
  %% @doc Get URL to translated license at the Creative Commons website
  -spec language_url_for(binary(), #context{}) -> binary() | undefined.
  language_url_for(License, Context) ->
  