Cataloging: Fundamentals of the NLM® Classification
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Class Number Types
- Form numbers—Group of numbers in each schedule ranging generally from 1-49 which are used to classify materials by publication type (e.g., dictionaries, atlases) or special topic (e.g., history or legislation) (Cf. Module 6—Form Numbers)
- Table G—Annotated numbers which allow for geographic breakdown. Linked to auxiliary Table G listing. Always paired with .1 (Not Table G) number. (Cf. Module 5—Table G)
- A-Z— l sub arrangement of subordinate concepts. The .5 number is a placeholder and is not used alone. The A-Z number remains the same even if the caption changes. For example, the former caption for WZ 80.5.O6 was Orientals.
- Canceled numbers— Numbers made obsolete for the NLM Classification. Canceled class numbers are enclosed in brackets with the caption: [This number not used]. A cumulative list of canceled numbers is available at http://wwwsvlt.nlm.nih.gov/class/docs/CanceledClassNumbers.html.