From a recent conversation on the GP Developer forum:
I'm having difficulty updating POs using eConnect. The issue involves POs that have more than one line, and one of the lines have been received against. I need to be able to cancel the line that has no receipts.
I can't update the whole PO, because it has receipts...
In SOP, I can send in the lone line and it works. In POP, it is requiring the POP header node so I can't use that approach.