This is the object's relative name (Rn) — just the last path segment of its Dn, the piece this DefinitionDelTaskFsmTask instance contributes to its own address within the MIT tree. Each stage of the deletion state machine hands its actual work off to an internal UCS Manager task, and this object is the record of that specific spawned task. 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/del-task/fsm/stage-2/task-1`, so two sibling instances never end up with colliding addresses under the same parent.