This read-only Counter32 counts frames transmitted out this port's egress direction with the Discard Eligible (DE) bit set to 1, marking them as lower-priority traffic that can be dropped first under congestion. An admin monitoring this value gets visibility into how much of the outbound traffic on the port is being flagged as expendable, which is useful for capacity planning and for confirming DE marking policies are being applied as configured. If this count is unexpectedly high on a port carrying critical voice or data traffic, it would prompt a review of the DE-marking rules upstream.