This indicates the direction of this ERM notification -- effectively whether it represents a rising-threshold up crossing, resource usage getting worse, or a falling-threshold down crossing, resource usage recovering. This is the field that lets an automated alert-management system distinguish, without inspecting the raw threshold value, whether an incoming trap is a new problem to open a ticket for or a resolution that should close an existing one. A ticketing integration watching for this field to flip from up to down on the same resource/policy pairing is how it would know to automatically close out a previously opened incident.