The IMPLICIT_ACKNOWLEDGEMENT and EXPLICIT_ACKNOWLEDGEMENT modes are assigned to a QAManager instance using the QAManager::open()
method. The TRANSACTIONAL mode is implicitly assigned to QATransactionalManager instances.
In implicit acknowledgement mode, messages are acknowledged as soon as they are received by a client application. In explicit
acknowledgement mode, you must call one of the QAManager acknowledgement methods. In transactional mode, you must call the
QATransactionalManager::commit() method to acknowledge all outstanding messages. The server propagates all status changes
from client to client.