Too many ISBNs on record

There is more than one subfield a in MARC tag 020 or there are more than two 020 MARC tags on the record. Frequently records provided by book distributors will contain ISBN numbers for all of the formats available for that title, including hard back, paperback, sound recording, movie, etc. Any extraneous ISBNs that do not describe the item that is held by the library should be deleted from the record, before submitting.