Common device identifiers include Media Access Control (MAC) addresses, Internet Protocol (IP) addresses, or device-unique token identifiers. The management of individual identifiers is not applicable to shared system accounts. Typically, individual identifiers are the usernames of the system accounts assigned to those individuals. In such instances, the account management activities of AC-2 use account names provided by IA-4 . Identifier management also addresses individual identifiers not necessarily associated with system accounts. Preventing the reuse of identifiers implies preventing the assignment of previously used individual, group, role, service, or device identifiers to different individuals, groups, roles, services, or devices.