January 15, 2021

With the focus on linked data, libraries now request that we provide the information when a bib term is matched to an appropriate authority record. We can insert the control number of the authority record or the URI of the authority record into subfield $0 of the bib record (recommended).

Example of control number in subfield $0 of a bib record:

650_0 $a Drawing. $0 (DLC) sh 85039408

If this option is chosen, subfield $0 control numbers will be added for the following vocabularies: AAT, ACP, FAST, GSAFD, LAC, LCSH, LCGFT, MeSH, NASA, NLA, Sears, TGM.

Example of a URI in subfield $0 of a bib record:

100 1 $a Kelly, Katy, $0 http://id.loc.gov/authorities/names/n88121754 $e author.

If this option is chosen, subfield $0 URIs will be added for the following vocabularies: ACP, FAST, LCSH, LCGFT, MeSH, TGM.

There’s been some documentation from PCC declaring a preference for using URIs that represent full matching access points and not partial access points as we provide.

October 2017    PCC Task Group on URIs in MARC Year 2 Report to PoCo (October 2017) (page 5)
“After careful consideration, the Task Group recommends against providing URIs that represent only partial entities of a MARC field. Faceted vocabularies provide an alternative means to represent such concepts by post-coordination. If the entire concept is to be represented as a single semantic unit within the LCSH vocabulary, in our view that becomes an issue for the maintenance agency rather than for implementers.”
https://www.loc.gov/aba/pcc/bibframe/TaskGroups/PCC_URI_TG_20171015_Report.pdf

This recommendation was repeated in a 2019 report (quoted from the 2017 report above): 09/12/19   PCC Task Group on Linked Data Best Practices Final Report (page 9)
https://www.loc.gov/aba/pcc/taskgroup/linked-data-best-practices-final-report.pdf

To date, we have not seen anything from the Library of Congress regarding community-wide adoption of these recommendations and it may be up to the library to choose to follow them or not. In response to customer inquiry, we will now insert subfield $0 when either a full or partial access point matches an authority record, or only when a full access point matches an authority record.

Which option is best? It really is up to the library.  If a library want to follow PCC stated best practices, they should get $0 URIs for full matching access points only.  However, this will result in a lot fewer added $0 subfields in their bib records and this additional information may be missed.  Unless the library is experimenting with Bibframe and the Sinopia linked-data editing environment, we suggest that the option to get $0 subfields for full and partial matches be chosen.  Since this is an ever-evolving area, this is likely not the last URI recommendation we will see from PCC.  It may well be that partial match URIs are acceptable in the future.

It should be noted that the choices a library makes for adding $0 subfields do not affect which authority records are returned to the library, as these are an entirely separate processes in Authority Match.  Our authorities processing provides authority records to the library for the fullest matching string.  If the library chooses to add $0 subfields for full matches only, they will still receive authority records for full and some partial matches.  For example, there is no authority record match for this full string so a URI will not be added if the library chooses to add them for full access points only:

650_0 $a Automobiles $x Air conditioning $z Arizona.

However, the library does get two matching authority records for this string:

$a Automobiles $x Air conditioning                          sh 85010204

$z Arizona                                                                       n  79034873

Here’s another example:

650_0 $a Personality disorders $x Religious aspects $x Buddhism

There is no authority record match for this full string, so a URI will not be added IF the library chooses to add them for full access points only.  The library will get this matching authority record:

$a Personality disorders $x Religious aspects       sh2019101837

Whether a library chooses to follow the current PCC guidelines for $0 enrichment or not, we have an option that is best for your library.

Please feel free to contact us with any questions at [email protected], or if you wish to adjust your profile options.

Written by Candy Riley
Manager of Metadata Services