A context-unique value—a value unique within a specific context—that is associated with a device (for example, a string consisting of a network address).
Sources:
NIST SP 800-213
from
NIST SP 800-56A Rev. 3 - Adapted
NISTIR 8259A
from
NIST SP 800-56A Rev. 3 - Derived
NISTIR 8259B
from
ETSI EN 303 645 v2.1.0 - Adapted