This value is a text string carried inside an HP IPF (In-Path Filtering) trap under hpIpf02Events that spells out the details of whatever event just occurred, including any variable information tied to it. An admin reads it in a trap log or SNMP manager to understand exactly what triggered the alert without having to decode numeric event codes. For instance, the string might read something like 'Filter rule 12 blocked traffic from host 10.1.1.5' when a filtering event fires.