This is the relative name (RN) -- the final naming component appended to its parent's DN -- that distinguishes one port breakout capability record, which describes whether a specific fabric-interconnect or switch port can be split into multiple lower-speed ports (for example one 40G QSFP port broken into four 10G ports) 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 breakout capability record a given row of data actually belongs to without repeating the full path in every field. For a breakout capability record the RN is typically the last path segment shown in 'sys/switch-A/slot-1/breakout-cap', e.g. 'breakout-cap'.