This is the object's relative name (Rn) — just the last path segment of its Dn, the piece this Definition instance contributes to its own address within the MIT tree. 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 this kind of object the Rn is typically built from the same identifying value as its Dn's final segment, e.g. the tail end of `org-root/ep-qos-def-gold-video`, so two sibling instances never end up with colliding addresses under the same parent.