This X12 Transaction Set contains the format and establishes the data contents of the Purchase Order Change Acknowledgment/Request - Seller Initiated Transaction Set (865) for use within the context of an Electronic Data Interchange (EDI) environment. The transaction set can be used by the seller to convey acceptance or rejection of changes to a previously submitted purchase order from the buyer. The transaction set is used by the seller to accept, reject, or modify a purchase order. Also, the transaction set can be seller-initiated to change a purchase order.