This is a yes/no switch on an SDP (Service Distribution Point) bind that turns on counting of packets dropped because they carried an unexpected extra VLAN tag on ingress. An admin enables it, setting the value to true, only on the specific service bindings where they need visibility into that particular drop reason, since it defaults to false to avoid unnecessary counting overhead everywhere. For example, setting sdpBindIngressExtraVlanTagDropCount to true on a troubled SDP bind would start the paired packet and octet counters incrementing whenever double-tagged frames are rejected there.