2017/09/25     來源:NLM閱讀原文

As part of our efforts to prepare our cataloging data for a linked data environment, the National Library of Medicine (NLM) has determined that some of the MARC coding for the subject fields is not accurate and will not create true triple statements in an RDF environment.

Historically, all MARC 6XX fields used in NLM bibliographic records have been assigned a second indicator of "2" defined as Medical Subject Headings (MeSH). This is true for data in the 650, 651, and 655 fields which are all taken from the MeSH vocabulary. However, data in the 600, 610, 611, and 630 fields does not come from MeSH, it comes from the National Authority File (NAF). Therefore, coding these fields with a second indicator of "2" is erroneous information. A second indicator of "0" (Library of Congress Subject Headings) would also not be correct. Although Library of Congress uses the NAF form for these subjects, LCSH practices for construction of name and title access points allow additions to these fields that NLM does not permit.

To accurately portray these subject fields, the second indicator should be "7" (Source specified in $2) with an accompanying $2 naf added to the 6XX field and NLM would like to make these changes in its files.....more