This is the object's distinguished name (Dn) — the exact path in Cisco UCS Manager's Management Information Tree that addresses one specific instance of an egress QoS policy definition. This is the policy object a vNIC or vHBA template points to; it's what UCS Manager pushes down through the fabric interconnects to shape and prioritize that interface's outbound traffic. For example, this Dn might read something like `org-root/ep-qos-def-gold-video`, which is the handle UCS Central or a script calling the UCS XML API would use to fetch this exact record rather than every Definition in the domain.