P4205 call serial number assignment P4220

We are on the 9.2 environment.

Can someone confirm how the following process/transaction should work?

We use P4205 to 'return product' to the on hand total.

Scenario:

Previously ship confirm sales order 880919 with an assigned serial number of 1550 via P4205.

Need to reverse transaction. Using a version of P4205 the on hand is adjusted up. .

P4220 is called. Select serial number 1550 assigned to Sales Order 880919.

In reviewing the F4220, the serial number record is not deleted from the table. However, order information previously associated is cleared (Order, Account #, Line #, etc.).

Before

After

My question is.....should the record be deleted from F4220, or only the associated sales order information from the original shipment?