This is the relative name (RN) -- the final naming component appended to its parent's DN -- that distinguishes one boot-device constraint rule -- a catalog entry stating which boot-device types a given server or adapter model is permitted to use in a boot policy from its siblings under the same parent object. Reading the RN alongside the parent DN is how UCS Manager, and any SNMP poller querying it, reconstructs which boot device constraint a given row of data actually belongs to without repeating the full path in every field. For a boot device constraint the RN is typically the last path segment shown in 'sys/chassis-2/blade-5/boot-device-constraints', e.g. 'boot-device-constraints'.