If SupplyType = S, DocumentNumber should not be allowed to be overwritten if RecipientAction = A(Accepted) or P(Pending).

If SupplyType = S, DocumentNumber should not be allowed to be overwritten if RecipientAction = A(Accepted) or P(Pending).

This error states that you can not edit document once your vendor has taken action on that as accepted or pending.

You can't edit the document once the vendor has accepted the document or put it in Pending status.