Asynchronous Acknowledgement > Implementing Asynchronous Acknowledgement > Subscriber Message Request
  
Subscriber Message Request
If a subscriber is configured to require acknowledgement, each of its subscriber messages contains two session context properties named requiresAcknowledgement and businessEventID.The subscribing application checks the requiresAcknowledgement session context properties to determine if an acknowledgement is required.If an acknowledgement is required, the subscribing application retrieves the subscriber message ID from the businessEventID session context properties.