All articles on SAP FI
How To Get Accounting Document Number From Billing Document Number
Find out what's the link between billing document table and accounting document table
How To Park Accounting Documents Via BAPI BAPI_ACC_DOCUMENT_POST
Parking a document allows saving an SAP FI document without actually posting it. If you want to create parked documents programmatically, BAPI BAPI_ACC_DOCUMENT_POST can be used.