This is the distinguished name of the QoS policy Definition that this deletion task is in the process of removing. Deleting a QoS definition isn't instantaneous — UCS Manager has to unwind every reference to it on every fabric interconnect and adapter that used it, and this task object is what tracks that cleanup to completion. For a task cleaning up the 'gold-video' policy, this would hold that policy's original Dn, e.g. 'org-root/ep-qos-def-gold-video', preserved here so the task's target is still identifiable after the policy itself is gone.