This is about DBMS Change Notification, enhanced feature introduced from version 10g.
DBMS Change Notification can only be used for tables those are having length (including schema name) less than 30 characters. For example, Oracle Project module PA.PA_STD_BILL_RATE_SCHEDULES_ALL table length is more than 30, so this table can not be used for DBMS Change Notification.
Also DBMS Change Notification treats particular change as bulk if numbers of changed records are more than 80. In this case ROWID will be empty. So we won’t know the affected records.