This read-write Integer32 (1-65535) sets the globally configured TPID (Tag Protocol Identifier) value used for the outer service-provider VLAN tag in QinQ double-tagging, defaulting to 0x8100, and only applies on interfaces that don't have their own per-interface hh3cQinQv2IfServiceTPID override. An admin changes this from the 0x8100 default when interoperating with equipment that expects a different TPID (such as 0x88A8) to correctly recognize the outer service tag as a QinQ tag rather than an ordinary 802.1Q tag. For example, setting this to 0x88A8 (34984 decimal) globally would align the switch's outer-tag TPID with a carrier network using the standard 802.1ad service-tag value.