A read-write port list specifying the complete set of ports in a VLAN to which frames destined for this multicast MAC address are being explicitly forwarded, not including ports that only receive it implicitly. This lets an admin see, or set, exactly which ports a static multicast MAC entry is forwarded out of, useful for controlling exactly where a specific multicast stream's traffic is delivered within a VLAN. An admin restricting a multicast group to two specific ports would set this object to a port list containing only those two ports.