Void an already completed transaction. For example, suppose that, as the initiator, you successfully execute a RosettaNet PIP 3A4 transaction with one of your trading partners. The conversation ends when your trading partner receives the final Receipt ACK from you, indicating that you have received their Purchase Order Acceptance (POA). However, after the conversation ends, you encounter a semantic error in that partner's POA (for example, the POA states that you ordered four PCs instead of only two, as you stated in your PO Request).

Cancel a transaction in progress. For example, suppose that you, as the seller, have received a PIP 3A4 PO Request from your trading partner and have sent a Receipt ACK. While processing the PO in your internal system, you realize that you have a semantic problem with the PO received.