History of the Representation of the DDC in the MARC Classification Format

This article explores the history of the representation of the Dewey Decimal Classification (DDC) in the Machine Readable Cataloging (MARC) formats, with a special emphasis on the development of the MARC classification format. Until 2009, the format used to represent the DDC has been a proprietary one that predated the development of the MARC classification format. The need to replace the current editorial support system, the desire to deliver DDC data in a variety of formats to support different uses, and the increasingly global context of editorial work with translation partners around the world prompted the Dewey editorial team, along with OCLC research and development colleagues, to rethink the underlying representation of the DDC and choose the MARC 21 formats for classification and authority data. The discussion is framed with quotes from the writings of Nancy J. Williamson, whose analysis of the content of the Library of Congress Classification (LCC) schedules played a key role in shaping the original MARC classification format.