topic level configuration cleanup.policy not supported by rdkafka

[LarsKandler]

Hello,
I tried to use the topic level configuration "cleanup.policy" and got a RD_KAFKA_CONF_UNKNOWN error.
Browsing the rdkafka code showed that "cleanup.policy" is not in the
static const struct rd_kafka_property rd_kafka_properties[]
array.
Whats the reason for that ?
Thanks in advance

Lars :)