Appendix F - Format Changes
MARC 21 Authority
May 2026
This section is provided for the lists of format changes
that accompany each update to the MARC 21 Format for
Authority Data.
MARC 21 FORMAT FOR AUTHORITY DATA
FORMAT CHANGE LIST
Update No. 42, May 2026
This page documents the changes contained in the forty-second
update to the 1999 edition of the MARC 21 Format for
Authority Data. Update No. 42 (May 2025)
includes changes resulting from proposals that were
considered by the MARC 21 community since the publication of Update No. 41 (December 2025).
UPDATE 42 CHANGES
■ New content designators:
Indicators
1stPreferred variant heading in 430 (See From Tracing-Uniform Title)
2ndPreferred variant heading in 400 (See From Tracing-Personal Name)
2ndPreferred variant heading in 410 (See From Tracing-Corporate Name)
2ndPreferred variant heading in 411 (See From Tracing-Meeting Name)
2ndPreferred variant heading in 451 (See From Tracing-Geographic Name)
Indicator values
#No information provided in 400 (See From Tracing-Personal Name) 2nd indicator: Preferred variant heading
#No information provided in 410 (See From Tracing-Corporate Name) 2nd indicator: Preferred variant heading
#No information provided in 411 (See From Tracing-Meeting Name) 2nd indicator: Preferred variant heading
#No information provided in 430 (See From Tracing-Uniform Title) 1st indicator: Preferred variant heading
#No information provided in 451 (See From Tracing-Geographic Name) 2nd indicator: Preferred variant heading
1Preferred variant heading in 400 (See From Tracing-Personal Name) 2nd indicator: Preferred variant heading
1Preferred variant heading in 410 (See From Tracing-Corporate Name) 2nd indicator: Preferred variant heading
1Preferred variant heading in 411 (See From Tracing-Meeting Name) 2nd indicator: Preferred variant heading
1Preferred variant heading in 430 (See From Tracing-Uniform Title) 1st indicator: Preferred variant heading
1Preferred variant heading in 451 (See From Tracing-Geographic Name) 2nd indicator: Preferred variant heading