Solution : https://service.sap.com/sap/support/notes/164422 (SAP Service marketplace login required)
Key words :
milestone/final billing occurs, sales order item, additional key words, attached advance corrections, fixed accounting rate, incoming payment occurs, billing split occurs, billing document items, payment request items, billing split
Related Notes :
170679 | Billing item to be billed with accounting rate |
150893 | Down payment clearing with separate exchange rate |
113347 | Down payment process. as of Release 4.0x (standard) |