he 2004 edition of the NLM Classification incorporates all additions and changes to the schedules and index from August 2003 through April 2004.

Schedules

New class numbers were added and existing class numbers were canceled as needed to reflect changes in MeSH and the biomedical and related sciences literature cataloged.

Other Changes to the Schedule

• For the first time, canceled class numbers appear in normal sequence within the current schedules for informational purposes. These numbers are in square brackets, clearly marked with the caption: "This number not used." A compilation of these numbers is provided in Canceled Class Numbers.
• Lengthy notes at the beginning of each schedule have been reformatted to improve readability.
• Selected class number captions were augmented to clarify their scope, e.g., at WB 400, Nutrition Therapy was added to Dietetics. Diet therapy.
• Selected class number captions were changed to reflect changes in MeSH terminology, e.g., at QV 350, Antibiotics was changed to Anti-bacterial agents.
• Various instructional notes were added or modified to clarify classification practices, e.g., at WZ 23, "Classify here histories of institutes devoted to medical history; classify other institutes with the field" was added.

Index

MeSH Additions, Changes, and Deletions for 2004—Classification Implications

• Ninety-four (94) new main index entries were created, sixty-five (65) of which are from the 2004 MeSH; the remainder are MeSH terms from previous years.
• Numerous main index entries and cross references were changed or deleted to reflect changes in the MeSH vocabulary. Those entries that were changed are a subset of Changed Descriptors—2004. Those entries that were deleted are a subset of Deleted Descriptors—2004. In particular, major categories of index terms affected by MeSH changes include:
  
  

  Racial Stock and Ethnic Group terms, e.g.,

  Negroid Race to African Continental Ancestry Group

  Drugs and Chemicals, e.g.,

  Antibiotics to Anti-Bacterial Agents

  Plant terms, e.g.,

  Mustard to Mustard Plant

  Bacteria terms, e.g.,

  Budding and Appendaged Bacteria to Bacteria

Instructional Notes to Clarify NLM Classification Practices

• Various instructional notes were added to index entries to clarify classification practices. Major categories of index terms affected include:

  Nutrition—Specific guidance is given for classification of infants, children, and/or adolescents.

  Traditional medicine—Current practice (WB) is clearly differentiated from historical practice (WZ)

  Biography vs. history—Collective biography of physicians, etc. (WZ 150) is distinguished from non-biographical history (WZ 80.5)

  Patient transfer vs. lifting of patients—Guidance is given for classification of administrative transfers (WX 158) versus general patient lifting procedures (WY 100.2)

Other Changes to the Index

• Index entries with Library of Congress (LC) HM schedule numbers were maintained to reflect major changes in the LC schedule.
  
  
• All index entries pertaining to the schedule additions and changes were modified.

To learn more about the NLM Classification, see the Fact Sheet.

By Sharon R. Willis
Cataloging Section, Technical Services Division

Willis SR. NLM Classification 2004 Edition Now Available. NLM Tech Bull. 2004 Mar-Apr;(337):e5.