anchor.diff:  process(f, 'content-disposition', Disp) when is_record(Disp, sip_hdr_disposition) ->
       TypeBin = sip_binary:any_to_binary(Disp#sip_hdr_disposition.type),
       append_params(TypeBin, Disp#sip_hdr_disposition.params);
  +
  +%% 20.12 Content-Encoding
  +process(pn, <<"e">>, _Ignore) -> 'content-encoding';
  +process(fn, 'content-encoding', _Ignore) -> <<"Content-Encoding">>;
  +process(p, 'content-encoding', Bin) ->
  +    {MethodBin, Rest} = sip_binary:parse_token(Bin),
  +    Method = sip_binary:binary_to_existing_atom(sip_binary:to_lower(MethodBin)),
  +    parse_list('content-encoding', Method, Rest);
  +
  +process(f, 'content-encoding', Allow) ->
  +    sip_binary:any_to_binary(Allow);
   
   %% .....
   process(pn, <<"v">>, _Ignore) -> 'via';
  
positive.code:                    format('content-disposition', #sip_hdr_disposition{type = 'icon', params = [{handling, optional}, {param, value}]})),
  
  
  
  
  
  
  
negative.code:      ?_assertEqual([{'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
                      {'from', <<"sip:alice@localhost">>}, {'to', <<"sip:bob@localhost">>},
                      {'call-id', <<"callid">>}, {'contact', <<"Alice <sip:example.com>">>},
                      {'supported', <<"100rel">>}, {'content-encoding', <<"gzip">>}],
                     parse_headers(<<"l: 5\r\nv: SIP/2.0/UDP localhost\r\nf: sip:alice@localhost\r\n",
                                     "t: sip:bob@localhost\r\ni: callid\r\nm: Alice <sip:example.com>\r\n",
                                     "k: 100rel\r\ne: gzip\r\n">>)),
       % multi-line headers
       ?_assertEqual([{'subject', <<"I know you're there, pick up the phone and talk to me!">>}],
                     parse_headers(<<"Subject: I know you're there,\r\n               pick up the phone   \r\n               and talk to me!\r\n">>)),
  