The pTarget parameter specifies a pointer to the object id for which notification is required. All fields except the edition field are required.
Setting either or both the classId and instId fields to zero (0) causes a masking effect. For example, setting instId to zero (0) and specifying a classId results in any instance of that class returning a notification when it receives a matching event.
Setting the classId field to zero (0) (the instId field must also be zero (0)) results in any instance of any class returning a notification when it receives a matching event.