anchor.diff:  		_ ->
   			ocs_rest:fields("id,href," ++ Filters, Object)
   	end;
  -usage_aaa_ipdr(Event, Filters) when is_record(Event, ipdr_voip) ->
  +usage_ipdr(Event, Filters) when is_record(Event, ipdr_voip) ->
   	UsageSpec = {struct, [{"id", "VoIPUsageSpec"},
   			{"href", ?usageSpecPath ++ "VoIPUsageSpec"},
   			{"name", "VoIPUsageSpec"}]},
  
positive.code: 		{_, {_, "AAAAccountingUsage"}, _Query1} ->
  			query_page1(PageServer, Etag, fun usage_aaa_acct/2, Filters, Start, End);
  		{_, {_, "PublicWLANAccessUsage"}, _Query1} ->
  			query_page1(PageServer, Etag, fun usage_aaa_ipdr/2, Filters, Start, End);
  		{_, {_, "VoIPUsage"}, _Query1} ->
  			query_page1(PageServer, Etag, fun usage_aaa_ipdr/2, Filters, Start, End);
  		{_, {_, "HTTPTransferUsage"}, _} ->
  			query_page1(PageServer, Etag, fun usage_http_transfer/2, Filters, Start, End);
  		{_, {_, _}, []} ->
  
negative.code: 	lists:reverse(Acc).
  
  %% @hidden
  usage_ipdr(Event, Filters) when is_record(Event, ipdr_wlan) ->
  	UsageSpec = {struct, [{"id", "PublicWLANAccessUsageSpec"},
  			{"href", ?usageSpecPath ++ "PublicWLANAccessUsageSpec"},
  			{"name", "PublicWLANAccessUsageSpec"}]},
  