Bowker Book Analysis System (BBAS) first tries to match each individual ISBN in the record. It will then place each in the appropriate file:
If no ISBN is present in the record, BBAS will look for an exact title match. It will use both the title and subtitle, strip out any spaces, and then look for an exact character match. There are three different types of title match that it will try:
If no records are matched in the first step, then it will go to second step and will continue to the third step if necessary.