The DefaultQueueManager stanza

The DefaultQueueManager stanza specifies the default queue manager for the node.

Name=default_queue_manager
The default queue manager processes any commands for which a queue manager name is not explicitly specified. The DefaultQueueManager attribute is automatically updated if you create a new default queue manager. If you inadvertently create a new default queue manager and then want to revert to the original, you must alter the DefaultQueueManager attribute manually.