This obsolete read-only flag is the ingress counterpart to zQosDot1pBcvlanin but applies to the outer, service-provider VLAN 802.1p tag rather than the inner customer tag, per its no-svlan-in/svlan-in enumeration. Since the source DESCRIPTION is only the terse label "bSvlanIn," its role is inferred from its name: toggling whether 802.1p priority inheritance is drawn from the ingress S-VLAN tag on a QinQ interface. Illustratively, a value of svlan-in(1) on this now-obsolete row would indicate the switch was inheriting priority from the outer S-VLAN tag rather than the inner C-VLAN tag on that port.