This is the Relative Name (Rn) of a Virtual Layer-3 Interface object, the in-band management routing interface configured on a UCS fabric interconnect, the naming component that distinguishes this instance from its sibling VirtL3Intf objects under the same parent in the UCS tree. Admins rarely read the Rn directly, but UCSM uses it to build the full Dn path, so it matters when correlating which parent object a given VirtL3Intf instance belongs to. For instance, if two VirtL3Intf objects sit under the same parent container, their Rn values are what tell UCSM (and any script parsing the Dn) apart which one is which.