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WorldCat Validation release notes, April 2026

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Release Date: 6 April 2026

Introduction

This release of changes to WorldCat Validation involves the following new features, enhancements, and bug fixes that support the Library of Congress's latest MARC standards, enable richer authority data for discovery, and resolve validation errors reported by the cataloging community.

  • New features and enhancements
    • OCLC-MARC Validations of New MARC Codes Announced 11 December 2025-27 January 2026
      • Cartographic Data Source Codes
      • Data Provenance Category Codes
      • Genre/Form Code and Term Source Codes
      • Musical Instrumentation and Voice Code Source Codes
      • Standard Identifier Source Codes
    • MARC 21 Bibliographic Update No. 41 (Announced December 2025)
    • MARC 21 Authority Update No. 41 (Announced December 2025)
    • MARC 21 Holdings Update No. 41 (Announced December 2025)

These enhancements and fixes are the result of announcements of new MARC elements and codes by the Library of Congress as well as feedback and requests from members of the OCLC community

New features and enhancements

OCLC-MARC Validations of New MARC Codes Announced 11 December 2025-27 January 2026

You may now use all new MARC Codes announced by the Library of Congress in the following LC Technical Notices and Update No. 41:

Cartographic Data Source Codes

The following source codes have been added to the Cartographic Data Source Codes list for usage in appropriate fields and elements.

  • azcor - Arizona coordinates (ALA: MAGIRT)
  • bbcou - Bounding boxes for countries (Humanitarian Data Exchange)
  • bbusc - Bounding boxes for all US counties (Anthony Louis D'Agostino)
  • bbuss - Bounding boxes for all US states (Anthony Louis D'Agostino)
  • cacor - California county coordinates (ALA: MAGIRT)
  • coubb - Country bounding boxes (Graydon Hoare)
  • iacor - Iowa county coordinates (ALA: MAGIRT)
  • ilcor - Illinois county coordinates (ALA: MAGIRT)
  • incor - Indiana state coordinates (ALA: MAGIRT)
  • micor - Michigan state coordinates (ALA: MAGIRT)
  • mncor - Minnesota county coordinates (ALA: MAGIRT)
  • mocor - Missouri county coordinates (ALA: MAGIRT)
  • nvcor - Nevada county coordinates (ALA: MAGIRT)
  • ohcor - Ohio state coordinates (ALA: MAGIRT)
  • stbbc - State bounding boxes (Crash Magic on Government Tools)
  • stbbg - State bounding boxes (Greg Larrenaga)
  • usbbs - U.S. state bounding boxes by state (Ryan Murphy)
  • uscbb - U.S. county bounding boxes (Ryan Murphy)
  • ussc - United States state coordinates (ALA: MAGIRT)
  • utcor - Utah state coordinates (ALA: MAGIRT)
  • wycor - Wyoming state coordinates: including national parks and monuments, and the Wind River Indian Reservation (ALA: MAGIRT)

Data Provenance Category Codes

With MARC 21 Bibliographic and Authority Update No. 41, the Data Provenance Category Codes and Data Provenance Relationship Codes have moved from Appendix H (Authority Format) and Appendix J (Bibliographic Format) to a new Data Provenance Code List. The following source code has been added to the Data Provenance Category Codes list for usage in appropriate fields and elements.

  • dpets - Data provenance element transliteration scheme

 Note: Code bcp47 from MARC Update No. 41 was added to WorldCat in the August 2025 Validation release.

Genre/Form Code and Term Source Codes

The following source codes have been added to the Genre/Form Code and Term Source Codes list for usage in appropriate fields and elements.

  • musvok-sf - Norsk musikkvokabular: sjangre og former (Oslo: Nasjonalbiblioteket)
  • wikidata - Wikidata

Musical Instrumentation and Voice Code Source Codes

The following source code has been added to the Musical Instrumentation and Voice Code Source Codes list for usage in appropriate fields and elements.

  • musvok-ie - Norsk musikkvokabular: Instrumenter og ensemble (Oslo: Nasjonalbiblioteket)

Standard Identifier Source Codes

The following source codes have been added to the Standard Identifier Source Codes list for usage in appropriate fields and elements.

  • schins - ScholarGPS institution (ScholarGPS)
  • schsch - ScholarGPS scholar (ScholarGPS)

MARC 21 Bibliographic Update No. 41 (Announced December 2025)

You may now begin to use the following changes to Bibliographic elements implemented as part of OCLC-MARC Bibliographic Update for April 2026, based on the MARC 21 Bibliographic format changes announced in MARC 21 Bibliographic Update No. 41 (December 2025).

  • In existing Bibliographic Videorecording element 007/04 (Videorecording format), code t (4K Ultra HD Blu-ray) has been defined. Code s (Blu-ray disc) has been redefined to explain the difference between Blu-ray and 4K Ultra HD Blu-ray.
  • In existing Bibliographic Maps elements 008/25 and 006/08 (Type of cartographic material), code r (Remote sensing image) has been defined.
  • In existing Bibliographic field 060 (National Library of Medicine Call Number), new subfield $6 (Linkage) has been defined.
  • In existing Bibliographic field 070 (National Agricultural Library Call Number), new subfield $6 (Linkage) has been defined.
  • In existing Bibliographic field 245 (Title Statement), new subfield $z (Title statement context note) has been defined. Subfield $c (Statement of responsibility, etc.) has been redescribed to allow for placement of subfields $7 (Data provenance) or $z after subfield $c.
  • In existing Bibliographic field 344 (Sound Characteristics), the definition of existing subfield $d (Groove characteristic) has been broadened to include the type of cutting (e.g., vertical cutting).
  • In existing Bibliographic field 381 (Other Distinguishing Characteristics of Work or Expression), new subfields $i (Relationship information) and $4 (Relationship) have been defined.
  • In existing Bibliographic field 884 (Description Conversion Information), subfield $g has been renamed Conversion date/time (formerly Conversion date), and the definition was broadened to include the time the data was converted.

MARC 21 Authority Update No. 41 (Announced December 2025)

You may now begin to use the following changes to Authority elements implemented as part of OCLC-MARC Authority Update for April 2026, based on the MARC 21 Authority format changes announced in MARC 21 Authority Update No. 41 (December 2025).

 Note: These changes apply only to the OCLC-MARC Authority validation rule set that includes all valid elements of MARC 21 Authority Format and cannot be used in the LC/NACO Authority File.

  • In existing Authority fields 368 (Other Attributes of Person or Corporate Body), 376 (Family Information), and 381 (Other Distinguishing Characteristics of Work or Expression), new subfields $i (Relationship information) and $4 (Relationship) have been defined.
  • In existing Authority field 368 (Other Attributes of Person or Corporate Body), subfield $2 (Source) has been redescribed to specify which subfields it controls.
  • In existing Authority field 884 (Description Conversion Information), subfield $g has been renamed Conversion date/time (formerly Conversion date), and the definition was broadened to include the time the data was converted. 

Name Authority Cooperative (NACO) participants cannot use new subfields $i or $4 in fields 368, 376, or 381 in the LC/NACO Authority File at this time. The Library of Congress and OCLC will announce the implementation of these elements for use in name and subject authority records in the LC/NACO Authority File at a future date.

MARC 21 Holdings Update No. 41 (Announced December 2025)

You may now begin to use the following changes to Holdings elements implemented as part of OCLC-MARC Holdings Update for April 2026, based on the MARC 21 Holdings format changes announced in MARC 21 Holdings Update No. 41 (December 2025). 

  • New Holdings field 655 (Index Term-Genre/Form) has been defined.
  • In existing Holdings field 884 (Description Conversion Information), subfield $g has been renamed Conversion date/time (formerly Conversion date), and the definition was broadened to include the time the data was converted.

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