This read-only object identifies which traffic policer (by its index number) should be applied to microflows that do not match any other QoS policy rules. If set to zero, unmatched traffic bypasses policing entirely; any non-zero value references a specific policer instance to enforce rate limits. An operator would check this to understand the fallback QoS policy for traffic that doesn't match explicit rules and adjust it to prevent non-conforming traffic from exceeding the link capacity.