This read-only counter tracks how many cells the port received from the attached customer equipment with the Cell Loss Priority bit already set to 1, marking them as discard-eligible before the card even processes them. An administrator uses it to see how much of the incoming traffic is arriving pre-marked as lower priority, which affects how policing and ingress queueing (tracked via ingrXmtCells) will treat it. A high ratio of ingrRcvClpSetCells to ingrRcvCells suggests the customer device is itself shaping or de-prioritizing a large share of its own traffic.