003 Control Number Identifier (NR) (Variable Control Field)
Field definition and scope:
Field 003 contains the MARC code for the agency whose system control number is present in field 001 (Control Number). See Appendix F for a listing of organization code sources used in MARC 21 records.
Whenever the number in field 001 is changed, agencies must assure that the MARC code in field 003 applies to the number found in the 001 field.
Field 003 is NOT repeatable.
Guidelines for applying content designators:
Field 003 has no indicators or subfield codes.
See: Examples
Input conventions:
Field 003 is usually system generated.
Related MARC fields or documents:
MARC Code List for Organizations
See also: