anchor.diff:  				{ServiceRating, ResultCode} = map_service_rating(ServiceElements, SessionId),
   				Container = build_container(MSCC1),
   				NewMSCC = build_mscc(ServiceRating, Container),
  +				ok = remove_ref(SessionId),
   				diameter_answer(SessionId, NewMSCC, ResultCode,
   						OHost, ORealm, RequestType, RequestNum);
   			{error, ReasonCode} ->
   				error_logger:error_report(["Rating Error",
   						{module, ?MODULE}, {error, ReasonCode}]),
  +				ok = remove_ref(SessionId),
   				diameter_error(SessionId, ReasonCode,
   						OHost, ORealm, RequestType, RequestNum)
   		end
  
positive.code: 			{ok, Body1};
  		{_RequestId, {{_HttpVersion, 200, _ReasonPhrase}, _Headers, Body1}} ->
  			{ok, Body1};
  		{_RequestId, {{_HttpVersion, StatusCode, _ReasonPhrase}, _Headers, _Body1}} ->
  			{error, StatusCode};
  		{_RequestId, {error, Reason}} ->
  
negative.code: 			RatingDataRef;
  		_ ->
  			[]
  	end.
  
  -spec remove_ref(SessionId) -> Result
  	when
  		SessionId :: binary(),
  		Result :: ok | {error, Reason},
  		Reason :: term().
  %% @doc Remove a rating data ref
  %% @hidden
  remove_ref(SessionId)
  		when is_list(SessionId) ->
  	Pattern = {SessionId, '$1'},
  	case catch ets:delete_object(?NRF_TABLE, Pattern) of
  		true ->	
  			ok;
  		{'EXIT', Reason} ->
  			{error, Reason}
  	end.
  
  -spec build_mscc(ServiceRating, Container) -> Result
  