anchor.diff:              <<Bin/binary, ?SP, DelayBin/binary>>
       end;
   
  +%% 20.39 To
  +%% http://tools.ietf.org/html/rfc3261#section-20.38
  +process(pn, <<"t">>, _Ignore) -> 'to';
  +process(fn, 'to', _Ignore) -> <<"To">>;
  +process(p, 'to', Bin) ->
  +    {Top, <<>>} = parse_address(Bin, fun parse_generic_param/2),
  +    Top;
  +
  +process(f, 'to', Addr) when is_record(Addr, sip_hdr_address) ->
  +    format_address(Addr);
  +
   
   
   %% .....
  
positive.code:                    format('to', address(<<"Bob Zert">>, <<"sip:bob@biloxi.com">>, [{'tag', <<"1928301774">>}]))),
       ?_assertEqual(<<"\"Bob \\\"Zert\" <sip:bob@biloxi.com>;tag=1928301774">>,
                     format('to', address(<<"Bob \"Zert">>, <<"sip:bob@biloxi.com">>, [{'tag', <<"1928301774">>}]))),
  
  
       % Via
  
negative.code:      ?_assertEqual([foo, bar], parse('require', <<"foo, bar">>)),
       ?_assertEqual(<<"foo, bar">>, format('require', [foo, bar])),
  
       % If the URI is not enclosed in angle brackets, any semicolon-delimited
       % parameters are header-parameters, not URI parameters, Section 20.
       ?_assertEqual({address(<<>>,
  