The JMS 1.1 specification does not specify what characters are valid in a durable subscription name.
It is proposed that the JMS 2.0 specification defines a minimum set of characters which are valid in a durable or non-durable subscription name.
This is needed to allow portable applications to be created. It is also needed because
EJB_SPEC-41 states that if a MDB is defined with subscriptionDurability set to Durable but subscriptionName is not set then the container will automatically set subscriptionName to a suitably unique global name of the MDB, and the container vendor needs to be sure that the name it generates will always be a legal subscription name.