This read-create integer, 0-65535 and defaulting to 0, identifies which entry in the RMON event table is triggered when this alarm's falling threshold is crossed; a value of 0 means no event is generated since zero is not a valid event index, and it cannot be modified once the entry's status is valid. Admins set it to link a falling-threshold crossing - such as a value returning to normal - to a specific logged or trap-generating event action. For example, an admin might point h3cRmonExtAlarmFallingEvtIndex at an event entry that logs a recovery message once CPU utilization drops back below the falling threshold.