PPDS - Item Category determination of PR/PO in ECC for APO created PR/PO

Hi All:

How does the ECC determines the Item Category (Standard, Subcontracting, Stock Transfer, etc) for PR/PO that are created in APO based on the info in the Transportation lane?

Literature says that ECC will use the Procurement Form in the Transportation lane of the material-locations to determine the item category and there are only three Procurement forms in the TL in APO (Standard, Subcontracting and Consignment).

Question is, if the Procurement Form is Standard and if the PR or PO is for stock transport (item category U), what other info from APO will ECC use to determine the correct Item category in ECC, which it does?

Pl. help.

Thanks

Ryan