Hi, Raymund-- I overlay (and thus update) authority records based on the 010 $a all the time without any problems--the match & authority record overlay works perfectly. When the appropriate script(s) run on Friday night, all my linked fields in bibs are updated, which also works perfectly. Some of our authority records are in our system from our initial data load (from an Athena catalog, loaded to our new Koha catalog by ByWater Solutions), and I currently export authority records from OCLC using Connexion Client into a file and then import them into Koha using the stage records for import tool, since there's not yet a gateway export for authorities. It works perfectly no matter the original source of the authority record. Here's what an 010 field of ours looks like when I save an authority record from Koha as MARCXML, so you can see an example: <datafield tag="010" ind1=" " ind2=" "><subfield code="a">n 98048791 </subfield></datafield> I'm very far from an expert--I am a cataloger!:)--but it doesn't sound like a bug to me. It sounds to me like something is going on with your 010 fields from Voyager and that they may need to be standardized. (We are using the fully open source version of Koha 3.22, hosted and supported by ByWater Solutions.) I hope this is helpful! Best, heather ~~~~~~~~~~~~~~ Heather Hernandez Technical Services Librarian San Francisco Maritime National Historical Park Research Center 2 Marina Blvd., Bldg. E, 3rd floor, San Francisco, CA 94123 415-561-7032, heather_hernandez@nps.gov http://www.nps.gov/safr/learn/historyculture/museum-collections.htm "The sailor does not pray for wind, he learns to sail."--Gustaf Lindborg