This holds the rn — the Relative Name — of the capability entry recording which physical ports on a piece of UCS gear are certified to accept passive optical/AOC cabling instead of copper twinax; it is only the final path segment identifying this object relative to its immediate parent, not the whole dn. Because a non-copper-passive-cabling port capability entry 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/non-copper-passive-1', the rn would just be the trailing segment 'non-copper-passive-1'.