PBXX required for free of charge PO

Hi All,

I have a PO document type to be used for internal purchase.

Internal purchase I mean is that a user department becomes the vendor on the PO of another user department.

We don't want to have any price on this PO, so I assigned purchase order field selection key: $DE1 - without entry of price

to the document type.

When I try to create a PO with this document type, net price and free item flag is successfully grayed out.

However, PBXX is required to enter in the item detail condition view.

How can I solve this problem? Why PBXX is required despite the item is free of charge?

Could anyone help me on this please?

Thanks,

ATO