This value lists the extra, non-identifying fields (such as byte or packet counters) that a NetflowRecordDef includes in each exported record in addition to the flow key fields. An administrator sizing a NetFlow collector's storage and processing needs nonkeys to know what additional per-flow measurements will actually be present in the exported data beyond just source and destination. For example, a record definition whose nonkeys includes packet counts lets a downstream analytics tool report packets-per-flow, whereas one without it can only report that a flow existed.