This counter reports the number of packets that were dropped as a result of the 'conform' policing action, i.e. traffic that already conforms to the rate limit set on the interface. It only increments when the policy's configured action for 'conform' traffic is to discard it rather than forward or remark it. A rising value here, without a matching rise in the non-dropped counter for the same class, indicates the policy is actively discarding more of that traffic category.