# description
 Specifies the mode, immediate versus deferred or queued, by which a receiver should communicate its receiver responsibilities.

# concept[].definition
The receiver may respond in a non-immediate manner. Note: this will be the default value.

# concept[].definition
The receiver is required to assume that the sender is blocking and behave appropriately by sending an immediate response.

# concept[].definition
The receiver shall keep any application responses in a queue until such time as the queue is polled.