To establish your interest in sublist transition monitoring, specify the EMCSTGPCT and the VECTORLEN parameters on the IXLCONN macro invocation when you connect to the list structure. Specifying EMCSTGPCT indicates the amount of space in the list structure's available storage that you want to allocate to event monitor controls. Specifying VECTORLEN will cause a list notification vector to be created for your connection's use. The system will update the associated entry in the list notification vector when the your event queue transitions from empty to nonempty.