TPs can synchronize their communications by requesting and granting confirmations. In some situations, a TP might need to confirm that its partner has received and successfully processed data already sent. For example, a TP that is uploading data from a workstation to the host would not want to delete the data until it is sure its partner on the host received it. When the sending TP requests a confirmation, APPC sends any buffered data to the partner. When the partner receives all the data, the partner also receives the confirmation request; the partner can then grant the confirmation or reject it by sending an error notification. If a conversation is to include confirmations, the requesting TP must indicate that at the start of the conversation.