Hi Beni,
Related to your advice, I have create a new Item, managed by Serial Numbers - On Release Only.
Then I create a Inventory Goods Receipt, without specifying the Serial Number.
When I query to the OSRI and OSRN table in the database, I could not find any record related, - seems it different with your description where there should be "empty SN records".
Btw, I'm doing my test in SAP 8.82 PL 05.