anchor.diff:  process(p, 'subject', Bin) ->
       sip_binary:trim(Bin);
   
  +%% 20.37 Supported
  +%% http://tools.ietf.org/html/rfc3261#section-20.37
  +process(pn, <<"k">>, _Ignore) -> 'supported';
  +process(fn, 'supported', _Ignore) -> <<"Supported">>;
  +process(p, 'supported', Bin) ->
  +    {ExtBin, Rest} = sip_binary:parse_token(Bin),
  +    Ext = sip_binary:binary_to_existing_atom(sip_binary:to_lower(ExtBin)),
  +    parse_list('supported', Ext, Rest);
  +
  +process(f, 'supported', Ext) ->
  +    sip_binary:any_to_binary(Ext);
  +
  +
  +
   %% .....
   process(pn, <<"v">>, _Ignore) -> 'via';
   process(fn, 'via', _Ignore) -> <<"Via">>;
  
positive.code:      % Server
       ?_assertEqual(<<"HomeServer v2">>, parse('server', <<"HomeServer v2">>)),
       ?_assertEqual(<<"HomeServer v2">>, format('server', <<"HomeServer v2">>)),
       
       % Subject
       ?_assertEqual(<<"Need more boxes">>, parse('subject', <<"Need more boxes">>)),
       ?_assertEqual(<<"Need more boxes">>, format('subject', <<"Need more boxes">>)),
       
  
       % To
       ?_assertEqual(address(<<"Bob Zert">>, <<"sip:bob@biloxi.com">>, [{'tag', <<"1928301774">>}]),
  
negative.code:                                    {'reply-to', <<"Bob <sip:bob@biloxi.com>">>}, {'require', <<"foo">>},
                                     {'retry-after', <<"120">>}, {'route', <<"<sip:server10.biloxi.com;lr>">>},
                                     {'server', <<"HomeServer v2">>}, {'subject', <<"Need more boxes">>},
                                     {'supported', <<"100rel">>},
  
  
                                     {'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
                                     {'to', <<"sip:bob@localhost">>},
                                     {'x-custom-atom', 25},
                                     {'allow', <<"INVITE, ACK, CANCEL, OPTIONS, BYE">>},
                                     {'unsupported', <<"bar, baz">>},
                                     {<<"X-Custom">>, <<"value">>}])),
  
       % Already parsed
  