This is the Relative Name of a LunDisk instance, the naming property that distinguishes this particular disk from its sibling LunDisk objects under the same parent LUN. An admin uses it to tell apart multiple disks participating in the same LUN when only the naming component (not the full path) is relevant, such as when scripting per-disk checks. For example, if a LUN spans several physical disks, the Rn lets an admin identify which specific disk entry in a table corresponds to slot or disk number two.