This holds the rn — the Relative Name — of the definition record for one built-in (onboard) component — such as an embedded LOM NIC or storage controller — soldered onto a specific server model's system board; it is only the final path segment identifying this object relative to its immediate parent, not the whole dn. Because a onboard-device definition record is nested under a parent object in UCS Manager's tree, the rn is what distinguishes it from sibling entries under that same parent without repeating the full ancestor path every time. For an object whose dn is 'capabilities/onboard-device-1', the rn would just be the trailing segment 'onboard-device-1'.