This read-only INTEGER flag indicates whether a filter's usage has exceeded its configured threshold and the resulting alarm hasn't yet been acknowledged by the NMS; the description notes a direct poll will always read False since the device only reports True via an unsolicited trap. Admins rely on the trap notification rather than polling this value to learn when a filter has tripped its alarm threshold. Because polling filterThreshFlag always returns False, an admin must watch for the corresponding SNMP trap rather than periodically reading this object to catch a threshold breach.