This object supplies a second unique index, also up to 65535, used in fan-temperature trap definitions, distinct from the tray-level index and intended to identify the specific sensor or event instance within that trap. An admin uses this identifier to disambiguate between multiple concurrent temperature alarms reported from the same tray. For example, two simultaneous over-temperature traps from the same tray but with different NotifId values tell the admin two different sensors tripped, not one sensor reported twice.