This read-create object sets the customer VLAN ID (C-VID) that a multicast VLAN (M-VID) is translated to on a specific interface, identified by ifIndex and subinterface index in the same table row; a value of 0 means translation to untagged packets. Admins use this to override the global multicast VLAN translation on a per-interface basis, for instance when one access interface needs a different customer-facing VLAN tag than the rest of the device. For example, setting this to 200 on a particular interface's entry would tag multicast traffic for that M-VID with C-VID 200 only on that interface, independent of the global translation setting.