This holds the rn — the Relative Name — of the capability entry describing how much on-chip packet-buffer memory a Fabric Interconnect's switching ASIC has available for lossless, Priority-Flow-Control traffic classes; it is only the final path segment identifying this object relative to its immediate parent, not the whole dn. Because a Priority Flow Control MMU 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/pfc-mmu-cap-1', the rn would just be the trailing segment 'pfc-mmu-cap-1'.