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About Thing 20

Purpose: Adding linked data pieces in our MARC records now will make the transition to a fully linked-data world easier and smoother. 

Learning Outcomes: Participants will learn which fields already defined for use in MARC records can be used with linked data applications and uses.

Intended Audience: Intermediate

Author: Lizzy Baus, Macalester College

Expected Duration: 45-60 minutes

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

Getting Started

We’ve talked a lot about Linked Data formats, projects, visions, and goals. But what can the average cataloger do right now, with the existing infrastructure and systems, to increase the linkability of our library data?

There is good news: many fields and subfields in the MARC21 Bibliographic format have been defined for use with Linked Data objects. Chief among these is $1 for a real world object URI, defined for use in lots of important MARC fields. This allows us to add pieces of Linked Data into our legacy records right now, without having to wait for new systems and standards that are designed around Linked Data from the ground up. (Some systems may even have URI insertion tools already, so the cataloger need not enter them manually.) It is a way to bridge the past and the future while things are still in development. This will also make it smoother when we finally are able to transition to new systems - some of our valuable linking information will already be present and ready for use. 

For example, you might have a record with the following:

100  1  Jemison, Mae, ǂd 1965- ǂe author ǂ1

That information being present in the record means it is available and actionable by scripts and other Linked Data tools. So even before we get to our Linked Data dreamland we can start to see some of its power. 


  • Read OCLC’s information about Control Subfields in general, and focus in particular on Subfield 0 and Subfield 1. 
  • Take a look at a MARC record that uses these control subfields. Look at where they appear and think about what information they add to the record. Some examples include: 
    • A queer history of the United States for young people, OCLC #1089258677
    • Nepantla : an anthology for queer poets of color, OCLC #1008775259
    • Gravity, OCLC #870305395
    • Comic drama in the low countries, c.1450-1560 : a critical anthology, OCLC #742510466
    • Memories lost, OCLC #924738796
  • Choose three resources in your library’s collection. For each one, find at least one Real World Object URI and add it to the appropriate MARC field. For instance, you can find the page for the author or illustrator, or you can find a geonames tag for a place named in a 651 field. 


How might you use these pieces of Linked Data now, in your organization? Think about how this could connect to Wikidata and other things we’ve learned about. 

Consider sharing your thoughts in the Comments section at the bottom of the page.

Additional Resources

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How might you use these pieces of Linked Data now, in your organization? Think about how this could connect to Wikidata and other things we’ve learned about.