anchor.diff:  	Value1 = {struct, [Typ1]},
   	Value = {usageSpecCharacteristicValue, {array, [Value1]}},
   	[{struct, [Name, Desc, Conf, Value]} | Acc].
  -
  -%% @hidden
  -spec_timestamp() ->
  -	Name = {name, "timeStamp"},
  -	Desc = {description, "Time and date request was processed by OCS."},
  -	Conf = {configurable, true},
  -	Typ1 = {valueType, "dateTime"},
  -	Value1 = {struct, [Typ1]},
  -	Value = {usageSpecCharacteristicValue, {array, [Value1]}},
  -	{struct, [Name, Desc, Conf, Value]}.
   
   %% @hidden
   spec_protocol() ->
  
positive.code: 	Start = {startDateTime, "2017-01-01T00:00:00Z"},
  	End = {endDateTime, "2017-12-31T23:59:59Z"},
  	Valid = {validFor, {struct, [Start, End]}},
  	Chars = [spec_timestamp(), spec_protocol(), spec_node(),
  			spec_server_address(), spec_server_port(), spec_type_accounting(),
  			spec_attr_username(), spec_attr_nas_ip(), spec_attr_nas_port(),
  			spec_attr_service_type(), spec_attr_framed_address(),
  			spec_attr_framed_netmask(), spec_attr_framed_routing(),
  
negative.code: 	Start = {startDateTime, "2017-01-01T00:00:00Z"},
  	End = {endDateTime, "2017-12-31T23:59:59Z"},
  	Valid = {validFor, {struct, [Start, End]}},
  	Chars = [spec_protocol(), spec_node(), spec_server_address(),
  			spec_server_port(), spec_client_address(),
  			spec_client_port(), spec_type_access(),
  			spec_attr_username(), spec_attr_nas_ip(),
  			spec_attr_nas_port(), spec_attr_service_type(),
  