Bibliographic Framework Initiative (Library of Congress)

The Library of Congress > BIBFRAME > MARC 21 to BIBFRAME 2 Conversion Specifications

The following specifications were developed to support the use of BIBFRAME 2 at the Library of Congress. They map the conversion of MARC Bibliographic record fields to BIBFRAME Hub, Work, Instance and Item.

MARC Bibliographic Conversion Specifications

Usage Notes

These specifications are written from the perspective of MARC so that each element in MARC is considered, even if not converted. The specifications are presented in Microsoft Excel files accompanied by a few explanatory specifications in Microsoft Word documents. If there is little or no use of an element in the Library of Congress records, the specifications usually say “nac” (no attempt to convert) in the conversion column. MARC fields and subfields that have been recently approved for the MARC21 format might be listed as “nac” initially, but the specifications may be modified as these fields begin to be used. Some elements in a MARC record are not relevant outside the MARC environment, and they are simply marked “ignore.”

A shorthand is used for the specification of the conversion from MARC to BIBFRAME RDF. The shorthand uses W for Work, I for Instance, but Item for Item and Hub for Hub. The specifications use the vocabularies from in a number of cases, especially for names, subjects, genre terms, and individual elements from the 007 and 008 fields.

The specifications use local properties with strings for data that will be used when trying to match and merge data, to change the data to conform to the BIBFRAME model, and to identify labels and RWOs in the MADS name and subject files. These local elements from the “bflc” namespace are included in the conversion of names and titles. They will be eliminated from the RDF when the merge and match is complete, unless we see a need to keep some for data that will continue to come into our BIBFRAME environment from MARC.

The specifications will be changed as needed throughout the BIBFRAME 2 Pilot. The number of the specification (1.7, etc.) matches the current version of the MARC-to-BIBFRAME conversion program and a revision date is also included.

Last edit: 06/20/2024