This field records how much the counter for FCoE frames the adapter attempted to send but discarded instead of transmitting changed during the specific collection interval this historical record captured — a frozen snapshot of that one interval's increase, not a live running total. For a network admin, this usually tracks a congested or paused fabric-facing uplink, since FCoE relies on Ethernet PFC pause frames to avoid loss and a spike here means that pause mechanism is being overwhelmed. For example, 8 frames in the last interval on this specific FCoE path would already be worth a closer look, since this counter should normally sit at or near zero.