Staged MARC Record Management
Finally, we will import these records into Koha and see the items have been created. When working with the Stage Records for Import tool, Koha will tell you how many records and items it found, and give a list of the MARC records. Once the library chooses to import these records, Koha will assign a bibliographic number and the magic has happened. Your library now has successfully imported a file of records and created items at the same time!
Using MARC Modification Template From a Record
From the full-record display of a record, select edit, modify record using template.
This option will allow the record to be modified using a saved MARC modification template. When choosing this option, Koha will bring the user directly to the Batch MARC Record Tool, set up the record, and have the opportunity to choose which template to apply to this record.
Koha will send this to a processing queue, which will be alerted to the user. Koha will give a link to the processing queue, and once this edit has been applied, Koha will update the queue.
Background jobs can be found in Administration > Jobs. Tasks such as Batch Item Modification, Batch Record Deletion, and Batch Record Modification can be seen for when they were sent to be processed and when they have been processed. Here is an example of what is logged in the Background Jobs.
Templates For Specific MARC Data
The Batch Item Modification tool is a powerful cataloging resource that empowers librarians to make changes to their data for updates to shelving locations or new item types. Sometimes, though, librarians need to make adjustments based on criteria that are not in the existing item data, like making all the items associated with a particular publisher into their own collection code, for example. The tool in the cataloging module doesn't have a way to query these other criteria, but a SQL report can.
Reports can help identify these items, which identifies the materials that need to be modified, and with the inclusion of a column with the itemnumber, can even unlock a shortcut to unlocking batch tools without the intermediate step of exporting a barcode list.

The inclusion of the itemnumber column in my report made the batch actions with visible results possible. Reports can display up to 1000 items at a time, so this can be a great way to modify large portions of a collection at once.
The sample report I used queried by publisher info (a field in the biblioitems table), but for specific MARC data that is not already mapped to Koha fields in the biblio or items tables, a report can also query MARC data via biblio metadata. The possibilities are vast here - a library might be genrefying a shelving location and want to identify materials by some known subject headings, or e-books loaded into the catalog have started confusing patrons, so they want to identify materials by the 337 RDA media type field to identify which "items" should actually have a clearer item type of EBOOK. A report can identify these records, then the items attached to it, making it easy to modify them in bulk.
Can Indicators be Updated via MARC Modification Templates?
While Koha's MARC modifications are a powerful cataloging tool, modification templates do not currently interact with indicators in a MARC field. There is
an enhancement request for it in the Koha community.
Libraries have found other workarounds in the meantime, typically identifying records by MARC data via report (which can query based on modifier values), exporting the identified records, and then updating via software like MarcEdit and reimporting.
Tutorial Videos