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Cataloging and Metadata Management

Instructions for Deconstructing MeSH Subjects

 

NLM bibliographic records distributed after Dec. 2015 will be distributed in deconstructed format following NLM internal cataloging practices. All the existing NLM records will be redistributed in deconstructed format on January 6, 2016.

For libraries that currently have MeSH subjects in traditional strings and now wish to structure their subject headings in the same format as they appear in the NLM database, this document provides instructions for deconstructing headings found on older NLM MARC 21 records. If you want to update your records with MeSH locally this is how it should be done. These adjustments should be done only to MeSH subjects, which are identified in the MARC 21 650 field with a second indicator of "2."


1. Any valid MeSH geographical term appearing in ‡z should be moved to a 651 _2 ‡a. If a 650 is repeated with several ‡z's, use a single 650 for the topical heading and multiple 651s. If several 650s have the same ‡z, keep the multiple 650s, but just one instance of the 651.

Examples:

Old Headings

650 12   ‡a Medicine, Traditional ‡x history ‡z Germany.
650 22   ‡a Folklore ‡z Germany.

Deconstructed headings

650 12   ‡a Medicine, Traditional ‡x history.
650 22   ‡a Folklore.
651 _2   ‡a Germany.

 

Old Headings

650 12   ‡a Legislation, Medical ‡z Canada.
650 22   ‡a Legislation, Medical ‡z United States.

Deconstructed headings

650 12   ‡a Legislation, Medical.
651 _2   ‡a Canada.
651 _2   ‡a United States.

 

2. Any valid MeSH Publication Type (PT) appearing in ‡v should be moved to a 655  _2 ‡a. If a subject is repeated with several ‡v's, use a single 650 field for the subject and multiple 655 fields. If several 650s have the same ‡v, keep the multiple 650s, but just one instance of the 655.

Examples:

Old Subjects

650 22   ‡a Heart Diseases ‡x diagnosis ‡v Congresses.
650 12   ‡a Heart Diseases ‡x diagnosis ‡v Periodicals.

Deconstructed headings:

650 12   ‡a Heart Diseases ‡x diagnosis.
655 _2   ‡a Congresses.
655 _2   ‡a Periodicals.

 

Old Subjects

650 12   ‡a Health Status Indicators ‡v Tables.
650 22   ‡a Epidemiologic Methods ‡v Tables.
650 22   ‡a Mortality ‡v Tables.

Deconstructed headings:

650 12   ‡a Health Status Indicators.
650 22   ‡a Epidemiologic Methods.
650 22   ‡a Mortality.
655 _2   ‡a Tables.

 

3. If a ‡x subfield follows a ‡a subfield in the 650 field, is should be retained. Each different ‡a ‡x combination should be treated as a unique subject and retained. If a ‡x follows any other subfield, it should be removed from the record.

Examples:

Old Subjects

650 12   ‡a Hip Joint ‡x surgery.
650 22   ‡a Hip Joint ‡x anatomy & history

Deconstructed headings:

650 12   ‡a Hip Joint ‡x surgery.
650 22   ‡a Hip Joint ‡x anatomy & history

 

Old Subjects

650 12   ‡a Biotechnology ‡v Dictionary ‡x Bengali.
650 12   ‡a Biotechnology ‡v Dictionary ‡x English.

Deconstructed headings:

650 12   ‡a Biotechnology.
655 _2   ‡a Dictionary.

 

4. 650’s with a first indicator of 1 should precede 650’s with a first indicator of 2. Within each group the subjects will generally be in alphabetical order.

Complex Example:

Old Subjects

650 12   ‡a Coronary Artery Disease ‡x surgery ‡z United States ‡v Review.
650 12   ‡a Coronary Artery Disease ‡x surgery ‡z United States ‡v Statistics.
650 22   ‡a Angioplasty ‡z United States ‡v Review.
650 22   ‡a Angioplasty ‡z United States ‡v Statistics.
650 22   ‡a Coronary Artery Bypass ‡z United States ‡v Review.
650 22   ‡a Coronary Artery Bypass ‡z United States ‡v Statistics.
650 22   ‡a Coronary Artery Disease ‡x diagnosis ‡z United States ‡v Review.
650 22   ‡a Coronary Artery Disease ‡x diagnosis ‡z United States ‡v Statistics.
650 22   ‡a Treatment Outcome ‡z United States ‡v Review.
650 22   ‡a Treatment Outcome ‡z United States ‡v Statistics.

Deconstructed headings:

650 12   ‡a Coronary Artery Disease ‡x surgery.
650 22   ‡a Angioplasty.
650 22   ‡a Coronary Artery Bypass.
650 22   ‡a Coronary Artery Disease ‡x diagnosis.
650 22   ‡a Treatment Outcome.
651 _2   ‡a United States.
655 _2   ‡a Review.
655 _2   ‡a Statistics.