This is the relative name (RN) -- the final naming component appended to its parent's DN -- that distinguishes one capacity/expansion-module specification entry in the hardware catalog 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 capacity module spec a given row of data actually belongs to without repeating the full path in every field. For a capacity module spec the RN is typically the last path segment shown in 'sys/chassis-1/cap-mod-spec', e.g. 'cap-mod-spec'.