Koha How-To

Authorities Town Hall Recap

We had a great turnout for the Authorities Town Hall on Wednesday (8/24). In case you missed it, or if you’d like to view it again as a refresher, the slide show is here and the recording can be seen here.  In this blog I’ll describe the main authority system preferences and review the linker options/system preferences in a bit more detail than is visible in the slide show. I’ll also address some of the questions we received in the town hall but didn’t have time to cover fully. Fasten your seatbelts!

Authority System Preferences

Two system preferences exist that control how authorities are created during the cataloging process. The first is BiblioAddsAuthorities which controls whether you can create new authority records or if you are restricted to using existing authority records in your system. The second, AutoCreateAuthorities, controls the creation of new (machine generated) authorities.

These two authority system preferences work together. For example if you have AutoCreateAuthorities set to ‘generate’ you must have BiblioAddsAuthorities set to ‘allow’ in order to create the machine generated authority records. Here is a table that shows what happens in the interplay of these two system preferences.



Don’t allow



Koha creates authority records for headings that don’t have a matching authority record.

Authority driven tag is locked and an existing authority record must be chosen. No Machine Generated records are created.

Don’t Generate

Koha will not automatically generate authority records. User can select existing authority or enter free text in tag.

User must use existing authority record – cannot enter free text. No machine generated authority record is created.

The Authority “Linker” Script

Here is a step by step description of how the “link bibs to authorities” script works in Koha.

  1. Bibliographic and Authority records are created and indexed.

  2. The cron job runs on the server (link_bibs_to_authorities.pl)

  3. The cron job looks for an exact match between the tag in the bibliographic record and the authority tag

– A match means a complete match (including punctuation).

– If the script doesn’t find a match it may create a “machine generated authority record” or not depending on your settings in the system preferences (AutoCreateAuthorities set to generate)

  1. The cron job will or will not link the bibliographic tags to authorities based on the Linker System Preferences. Let’s take a look at those preferences:

CatalogModuleRelink – If the tag was previously linked to an authority record, opening and saving the bibliographic record will relink the authority controlled tags. This is primarily an issue when catalogers are editing records manually, but can have an effect on the linker script which does open and save records when creating links to authority records.

LinkerKeepStale – Do you want to keep the links to ‘old’ (non matched) authority records in the bibliographic tag? (do/do not)

LinkerModule – first match or last match or default. We recommend using the default setting here.

LinkerOptions – The only option that currently exists is “broader headings”. Using this option can create very broad headings that are not useful to patrons. Best to test this option on a test server before employing it in production. There is a great description in the Koha Manual explaining the intended behavior of this option.

LinkerRelink: A heading that has been already linked to authority can be relinked to a new authority if a new match is found. (do/do not)

Questions from the Group:

1. What about the deprecated series data in the 440/490 and the new 8XX tags? How are these linked?

In the example in my slideshow you will see the 440 tag linked to a Uniform Title. This is a holdover from AACR2. If you have records with a 440 tag it will link to a Uniform Title authority record. If you’ve updated your records with 490 and 800/810/811/830 tags you will see the 8XX tags linked to authority records, but not the 490.

2. Do subject searches include information stored in the 450 tags?

I am happy to admit I was wrong on this. I did not think the 4XX tags were indexed and searched during subject searches. Heather from SF Maritime sent me an example from her catalog (catalog.keys.bywatersolutions.com) that shows a subject search on a term in the 450 tag in the authority record produces the appropriate bibliographic that it is linked to. Her notes is below. Thanks Heather and this is great for me to know and great news for the librarian whose patrons are searching for ‘conjuring’ instead of ‘magic tricks’!

Found one: if you do a subject search in our catalog for “Handicapped” (which is a 450 in the aut record), the bib record retrieved has the 650 heading “People with disabilities” (which is in the 150 of that aut record).

3. How can I dedupe my Authorities?

There is not currently a way to dedupe authorities in batch. We do have a script that we can use to dedupe your authorities at the command line on the server. There is currently a community ticket about this issue and hopefully we will have access within Koha (maybe as a plugin) to do this soon! https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=13706

4. How do I see my unused authorities?

There is currently a plugin available to check for unused authority records. https://github.com/bywatersolutions/koha-plugin-unused-authority-check Contact us if you’d like more information about this.


Read more by Joy Nelson

Tags authorities tutorial, koha