The practice of inserting 007 in holdings record has changed after migrating from Aleph to Alma, in addition to Harvard Libraries moving away from the single record policy towards the multiple record policy. Consult the Metadata Standards Working Group's Best Practices on 33X and 007 in Alma Bibliographic and Holdings Records.
Basically, when the format described in the bibliographic record matches the format of the holdings record, do not copy 007 from bib to holdings. However, when the format represented by the holdings record is not reflected in the bibliographic record, create appropriate 007 field in the holdings record. See the MARC field documentation for precise codes.
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