This is the state of the ciiSysProtSuppEntry, following RowStatus behavior. It creates or removes an entry declaring which network-layer protocol this Intermediate System advertises support for in its protocol-supported TLVs, so deleting the entry for a protocol the router still actually forwards would misrepresent its capabilities to neighbors relying on that TLV. For example, adding an entry here for IPv6 support ensures the router correctly advertises dual-stack capability to IS-IS neighbors instead of being treated as IPv4-only when they form multi-topology adjacencies.