Solution : https://service.sap.com/sap/support/notes/38597 (SAP Service marketplace login required)
Key words :
additional key words mr08, manually inputed assignment number, field assignment number, usual default logic, field bseg-zuonr, previously created document, 'allocation number' field, allocation number, parked document, posted/ cancelled
Related Notes :
| 92486 | MR08: Field allocation no. when offsetting entries |
| 49560 | MR44 : Parked document cannot be posted |