Lists, as a port bitmap, which ports on this VLAN are manually (statically) configured as multicast router ports, always treated as router ports regardless of whether the switch actually detects router traffic on them; an admin sets this to pin a known upstream router-facing port, e.g. an uplink to a core router, rather than relying only on dynamic detection. The object's own DESCRIPTION is blank in this MIB; this reading follows from its position alongside the dynamic and forbidden router-port list objects.