A child policer parented to an arbiter can be enabled to forward traffic exceeding its PIR, in which case:
Traffic exceeding the operational PIR of the child policer is reprofiled to be exceed-profile, where the operational PIR is determined by the H-pol algorithm from the configuration of the policer parent and the associated arbiters (root and, or intermediate).
Traffic exceeding the child policer's operational PIR and exceed-profile traffic entering the child policer does not consume capacity from the parent policer (meaning that it does not contribute to the parent policer bucket depth with respect to any of its thresholds).
Traffic that did not exceed the child policer's operational PIR (when that child is configured with enable-exceed-pir) can exceed its parent rate (max-rate for the root arbiter) in which case the traffic is forwarded and reprofiled to be exceed-profile and its effect on the child policer is revoked (meaning that it does not contribute to any of the child policer bucket (PIR, CIR, FIR) depths with respect to any of its thresholds).