This read-only counter, in cells, tracks the number of valid, UPC/PCR-compliant EFCI=1 cells in the ingress direction of this channel that were discarded at the class-of-service queue. An admin cares because these cells were already flagged as having experienced congestion upstream and are now additionally being dropped locally, representing compounded congestion effects along the path. For example, an admin seeing high discard counts here for cells that arrived already EFCI-marked would recognize this connection is suffering congestion at multiple points along its path, not just at this switch.