This holds an additional key value UCS Central compares for uniqueness, used when the primary name alone isn't sufficient to detect a real collision. UCS Central raises one of these when it needs to verify that an identifier — such as a service-profile name or a pool ID — won't collide with one that already exists elsewhere, most commonly while registering or merging a UCS domain into UCS Central. For a service-profile duplicate check this might carry something like the profile's UUID suffix pool assignment, so two profiles with the same name in different orgs aren't wrongly flagged as duplicates.