This read-only Counter32 counts frames discarded in the egress direction on this port specifically because they exceeded the configured DE (Discard Eligible) threshold. This tells an admin that the port's egress queue management is actively shedding discard-eligible frames to protect higher-priority traffic during congestion, which is expected behavior under load but a warning sign if it happens constantly. Persistent growth in this counter during normal traffic hours would suggest the port's egress capacity or DE threshold needs to be re-tuned.