This read-only object mirrors the `rn` property of a physical I/O expander module -- an add-on board that gives a blade or compute node extra mezzanine/PCIe ports inside Cisco UCS Manager's internal information model, exposed here as a text string for this I/O expander instance. The rn is just this object's own naming segment -- the last component appended to its parent's dn to build the full path -- rather than the whole path itself. For the IOE plugged into slot 2 of a UCS X210c compute node, the rn might be a short token like ioexpander-1 or locator-led-1, which UCS Manager concatenates onto the parent blade's dn.