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DB / Metadata Management Program (MMP): Fundamentals of the NLM® Classification

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Finding the Appropriate Class Number


  • Always check the main schedule for further instructions
  • Read all annotations in the schedule (Note: Some general annotations appear at the beginning of the schedule)
  • Take into account factors that may influence the classification (e.g., form, age group)

Specific Concepts

  • In the NLM Classification index, some subjects may be indexed to a specific number. Note: these class numbers will also be visible in the MeSH browser, but the schedules should still be checked

    Example:

    Screen capture of Reticulocytes to WH 150 in the NLM Classification index.

  • Always refer to the main schedule to verify the number to be certain there are no annotations directing the cataloger to use another number in specific circumstances

General Concepts

  • Some subjects may include a range of numbers. Refer to the section of the class schedule to which the primary subject is indexed and select the most appropriate number.

    Example:

    Screen capture of Kidney Diseases to WJ 300-378 in the NLM Classification index.

  • Refer to the section of the class schedule to which the primary subject is indexed and select the most appropriate number
  • Select the class number annotated "General Works" if:
    • the subject is very general
    • the primary focus of the work includes several subjects within the schedule


Last Reviewed: April 16, 2021