Solution : https://service.sap.com/sap/support/notes/445169 (SAP Service marketplace login required)
Key words :
additional key words purchase order, read purchase order dates, bapimmpara-selection default, extensions type spec, extensionout type spec, bapi interface bapi_po_get_detail, bapi bapi_po_get_detail, parameter 'extensions', reference type, parameter 'extensionout'
Related Notes :
| 395311 | BAPI_PO_CREATE: Customer enhancements not copied |
| 336589 | BAPI_PO_CREATE: Customer enhancements |