This is the rn (Relative Name), the single naming segment that, appended to its parent's dn, forms the full dn for this one instance of a statically assigned IPv4 management address, such as the fixed mgmt0 IP configured on a fabric interconnect rather than one obtained via DHCP. UCS Manager derives this segment automatically from the object's own defining attribute (such as an address, index, or configured name), so seeing a distinctive rn like this is how you tell one IpV4StaticAddr row apart from every sibling row under the same parent. For this class the rn typically looks like 'ipv4-static'.