i just noticed, after gotting a shock as PSC told me the same, that the documentation has a big bug:
Chapter 2: Using the JMS Test Client
— Integer values 0 (the highest) through 9 (the lowest)
Later, in the same doc, it's printed correct.
But who read this may be confused.
At least it is correct in the JavaDoc for javax.jms.Message and progress.message.client.Message. (It was still incorrect in Sonic 8.5... I am not sure about later versions of the doc.
9 is the highest (expedited) JMSPriority. 0 is the lowest.