This read-only counter, in cells, tracks the number of valid RM (Resource Management) cells received in the ingress direction of this channel before the class-of-service queue. An admin monitoring an ABR connection's closed-loop rate control uses this to confirm RM-cell feedback is actually flowing on this channel, which is essential for the ABR rate-adaptation mechanism to function. For example, if an ABR connection's throughput seems stuck at a conservative rate, the admin might check this RM-cell count to confirm feedback cells are arriving as expected before suspecting a rate-control misconfiguration.