MSMQ queues are referenced in three ways: by their MSMQ pathname, their format name, and a queue handle. The method that is used depends on what is happening with the queue.
First, the queue's MSMQ pathname is used to create a queue. After the queue exists, its format name is used to open the queue for sending or reading messages, resetting the queue's properties (including its security) and deleting the queue. After the queue is open, while messages are sent to the queue or read from the queue, a queue's handle is used.
For information on the three ways to reference the queue, see: