This read-write, write-only PortList lets an admin clear cached received-neighbor LLDP information for the specific ports whose bits are set, with an empty bitmap by default meaning no ports are cleared. It's useful after replacing equipment on a port when the switch is still showing stale data about the device that used to be connected there. For example, writing the bit for port 5 in this object clears out the LLDP data cached from the previous device before a new one is plugged in.