In addition, for the following number fields, if subfield $z is present, and subfield $a is missing, no Mandatory Fields error message will be shown: 015, 017, 024, 027, 030, 074, 086, 088. This cancellation is handled internally and there is no need to adjust your Mandatory Fields table accordingly. This change was made to make the program more in accord with the MARC examples (eg. “If no valid number exists, subfield $z may be used alone in the record”).