World classification:
030 – General Encyclopedic Works (for general classification systems)
Animal Taxonomy:
590 – Zoology (specifically, 593 for marine animals, 595 for insects, etc.)
Plant Taxonomy:
580 – Botany (specifically, 583 for dicotyledons, 585 for gymnosperms, etc.)
Scientific Disciplines:
500 – Natural Sciences & Mathematics (for general science classification)
Literary Genres:
800 – Literature, Rhetoric & Criticism (for general literary classification)
Art Movements:
700 – Arts & Recreation (for general art classification)
Philosophical Schools:
100 – Philosophy & Psychology (for general philosophical classification)
Language Families:
400 – Language (for general linguistic classification)
Music Genres:
780 – Music (for general music classification)
Geographical Regions:
910 – Geography & Travel (for general geographic classification)
Psychological Disorders:
616.89 – Mental Disorders (in the 610 – Medicine & Health category)
Periodic Table of Elements:
546 – Inorganic Chemistry (in the 540 – Chemistry category)
International Law Categories:
341 – International Law (in the 340 – Law category)
Economic Systems:
330 – Economics (for general economic classification)
Technological Eras:
609 – History, Geography & Biography of Technology (in the 600 – Technology category)
Human Cultures:
306 – Culture & Institutions (in the 300 – Social Sciences category)