An LUID is a 64-bit value guaranteed to be unique only on the system on which it was generated. The uniqueness of a locally unique identifier (LUID) is guaranteed only until the system is restarted.
An LUID is not for direct manipulation. Applications are to use functions and structures to manipulate LUID values.
typedef LARGE_INTEGER LUID
AllocateLocallyUniqueId, LookupPrivilegeName, LookupPrivilegeValue, PrivilegeCheck, LUID_AND_ATTRIBUTES, PRIVILEGE_SET