The recent enhancement to Preferred Term Correction correctly updates bibliographic headings when the preferred and non-preferred terms are in different authority fields (for example, 410 → 130), and changes the bibliographic field tag accordingly (e.g., 610 → 630).
However, the current implementation does not fully synchronize MARC indicators between authority and bibliographic records.

The enhancement documentation states:
"When a bibliographic field is updated to an X30 field, the non-filing indicators in the bibliographic record will be adjusted based on the linked authority record. According to MARC21 standards, the 1st indicator of authority field 130 (Nonfiling characters) will be copied to the 2nd indicator of the X30 bibliographic field."
This is not accurate. In MARC21 authority format, the 1st indicator of field 130 is undefined (#), and the 2nd indicator represents the number of nonfiling characters.
Specifically:

1. In cases involving authority field 130:
   o MARC21 defines the 2nd indicator of authority field 130 as the number of nonfiling characters.
   o In bibliographic X30 fields (130/630/730/830), the number of nonfiling characters is recorded in the 1st indicator.
   o Therefore, the system should correctly transfer the nonfiling value from the 2nd indicator of authority field 130 to the 1st indicator of the corresponding bibliographic X30 field.
   o In addition, the 2nd indicator of the bibliographic X30 field should not be modified as part of this process.

2. In all other controlled access points (1XX, 6XX, 7XX, 8XX):
   o Whenever a bibliographic heading is linked to an authority record, the 1st indicator of the bibliographic field should be automatically synchronized with the 1st indicator of the corresponding authority 1XX field.
   o If indicators differ, they should be updated to ensure full consistency.
   Without this synchronization, inconsistencies remain between authority data and bibliographic headings, generating additional manual maintenance and undermining the integrity of authority control.

Proposed Enhancement

Extend Preferred Term Correction to include automatic indicator alignment between authority records and all linked controlled bibliographic access points, in full compliance with MARC21 specifications.