Standard use of OrderIDAssignmentNotification in SNC?

We have a process in which our customers provide PO number ranges for use in replenishment orders. The number ranges are proveded via EDI and need to be stored in SNC for use. It appears that the standard service interface OrderIDAssignmentNotification is available for this requirement, however it SAP has only provided OrderIDAssignmentNotification_In. In order for PI to transfer the data to SNC I would expect OrderIDAssignmentNotification_Out to also be available. If OrderIDAssignmentNotification_Out does not exist, what is the standard process for mapping PO range information into OrderIDAssignmentNotification_In?

Thanks,

S. Parker