ist.

 <P>In some cases, a connection may both publish and subscribe to a topic.
 The subscriber <code>NoLocal</code> attribute allows a subscriber to inhibit
 the 
 delivery of messages published by its own connection.

 <P>If a client needs to receive all the messages published on a topic, 
 including the ones published while the subscriber is inactive, it uses 
 a durable <code>TopicSubscriber</code>. The JMS provider retains a record of
 this durable 
 subscription and insures that all messages from the