This counts how many times this router, while acting as master, has sent a priority-0 advertisement to deliberately signal it's stepping down from the master role, the sending-side counterpart to cVrrpStatisticsPriZeroPktsRcvd on the peer. It's the object to check to confirm a planned maintenance failover, like taking a router out of service gracefully, actually happened as an intentional, clean handoff rather than the master simply going silent and forcing the backup to time out and take over the hard way. A maintenance runbook that includes 'gracefully relinquish VRRP master' should show this counter increment exactly once per such event.