This OID, typed as TruthValue, reports whether that NetFlow monitoring session previously had a monitoring destination configured before its current state. An admin uses this flag to understand the history of a monitoring session's configuration, which matters when diagnosing why a session behaves differently than a freshly created one. A NetflowMonSession reporting true here indicates it once had a destination assigned, useful context if the session is now failing to export and the admin is comparing it against a brand-new one.