Messages that were originally sent to the receiving member may have been intercepted by exit IXZXIT01 and appended with additional data. Unless exit IXZXIT02 retrieves the extents from the extent queue, any extents added to the original message are lost. Such message extents are not automatically propagated beyond exit IXZXIT02. Therefore, exit IXZXIT02 must search for and match the message extent name on the queue of extents. XIT02_NAME_EXTENTS in the exit-specific segment of IXZ$XPL points to this queue.