Current bib bulk change does not allow deleting fields with specific data or deleting duplicate fields. For example, we can only delete the first instance, last instance or all instances of a MARC tag but we cannot delete a tag that contains specific data. This means in our consortium when weeding electronic resources like Kanopy for one library and not the others, we cannot tell Polaris to delete the 856s that contain one library’s URL and not the 856s for other libraries. We have to export the records out of Polaris, use MarcEdit to delete the 856 for the library then reload the records back to Polaris.
We also cannot delete tags with duplicate data in bib bulk change but have to delete the field from one record at a time or export to MarcEdit, delete the field then reload the records. For example, when records are merged, some fields like the 996 we use for our custom TOM are merged onto the new record, so we end up with duplicates.

It would be helpful if the ability to delete a tag containing specific data and ability to delete duplicate fields are included in Bib Bulk change.