anchor.diff:          ext_opts = [
               {<<"reg-id">>,<<"1">>},
               {<<"+sip.instance">>,
  -                <<"\"<urn:uuid:00000000-0000-0000-0000-000097ee887e>\"">>}]
  +                <<"<urn:uuid:00000000-0000-0000-0000-000097ee887e>">>}]
       }] =
           uris("<sip:xxxx@192.168.1.2:5060;transport=TCP;ob>;reg-id=1;"
                "+sip.instance=\"<urn:uuid:00000000-0000-0000-0000-000097ee887e>\""),
       [#uri{
  -        domain = <<"host">>, opts = [{<<"key">>,<<"\"my \\\"\"">>}],
  -        headers = [{<<"hd">>,<<"\"your \\\"\"">>}]
  +        domain = <<"host">>, opts = [{<<"key">>,<<"my \\\"\"?hd=\"your \\\"">>}]
       }] = uris("<sip:host;key=\"my \\\"\"?hd=\"your \\\"\">").
   
   
  
positive.code:             opts(Rest, Block, Uri1)
      end;
  
  opts_value([Ch|_]=Rest, Key, Acc, false, Block, Uri) when Ch==32; Ch==9; Ch==13 ->
      case strip(Rest) of
          [] ->
              opts_value([], Key, Acc, false, Block, Uri);
          [Ch1|_]=Rest1 when Ch1==$;; Ch1==$?; Ch1==$>; Ch1==$, ->
              opts_value(Rest1, Key, Acc, false, Block, Uri);
          _ ->
              {error, opts_value, ?LINE}
      end;
  
  opts_value([Ch|Rest], Key, Acc, Quoted, Block, Uri) ->
      opts_value(Rest, Key, [Ch|Acc], Quoted, Block, Uri).
  
  
  %% @private URI Header Keys
  
negative.code: 
  
  %% @private URI Opts Values
  opts_value([], Key, Acc, Quoted, _InnerQuoted, Block, Uri) ->
      case Acc==[] orelse Quoted of
          true ->
              {error, opts_value, ?LINE};
  