 | 500 Natural sciences & mathematics
 | 501 Philosophy & theory |
| 502 Miscellany |
| 503 Dictionaries & encyclopedias |
| 504 [unassigned] |
| 505 Serial publications |
| 506 Organizations & management |
| 507 Education, research, related topics |
| 508 Natural history |
| 509 Historical, geographic, persons treatment |
|
| 510 Mathematics
| 511 General principles of mathematics |
| 512 Algebra, number theory |
| 513 Arithmetic |
| 514 Topology |
| 515 Analysis |
| 516 Geometry |
| 517 [unassigned] |
| 518 [unassigned] |
| 519 Probabilities & applied mathematics |
|
| 520 Astronomy & allied sciences
| 521 Celestial mechanics |
| 522 Techniques, equipment, materials |
| 523 Specific celestial bodies & phenomena |
| 524 [unassigned] |
| 525 Earth (Astronomical geography) |
| 526 Mathematical geography |
| 527 Celestial navigation |
| 528 Ephemerides |
| 529 Chronology |
|
| 530 Physics
| 531 Classical mechanics/Solid mechanics |
| 532 Fluid mechanics/Liquid mechanics |
| 533 Pneumatics (Gas mechanics) |
| 534 Sound & related vibrations |
| 535 Light & paraphotic phenomena |
| 536 Heat |
| 537 Electricity & electronics |
| 538 Magnetism |
| 539 Modern physics |
|
| 540 Chemistry & allied sciences
| 541 Physical & theoretical chemistry |
| 542 Techniques, equipment, materials |
| 543 Analytical chemistry |
| 544 Qualitative analysis |
| 545 Quantitative analysis |
| 546 Inorganic chemistry |
| 547 Organic chemistry |
| 548 Crystallography |
| 549 Mineralogy |
|
| 550 Earth sciences
| 551 Geology, hydrology, meteorology |
| 552 Petrology |
| 553 Economic geology |
| 554 Earth sciences of Europe |
| 555 Earth sciences of Asia |
| 556 Earth sciences of Africa |
| 557 Earth sciences of North America |
| 558 Earth sciences of South America |
| 559 Earth sciences of other areas |
|
| 560 Paleontology/Paleozoology
| 561 Paleobotany; fossil microorganisms |
| 562 Fossil invertebrates |
| 563 Other fossil invertebrates |
| 564 Fossil Mollusca & Molluscoidea |
| 565 Fossil Arthropoda |
| 566 Fossil Chordata |
| 567 Fossil cold-blooded vertebrates |
| 568 Fossil Aves (birds) |
| 569 Fossil Mammalia |
|
| 570 Life sciences/Biology
| 571 Physiology & related subjects |
| 572 Biochemistry |
| 573 Specific systems in animals |
| 574 [unassigned] |
| 575 Specific parts of & systems in plants |
| 576 Genetics & evolution |
| 577 Ecology |
| 578 Natural history of organisms |
| 579 Microorganisms, fungi, algae |
|
| 580 Plants
| 581 Specific topics in natural history |
| 582 Plants noted for characteristics & flowers |
| 583 Magnoliopsida (Dicotyledons) |
| 584 Liliopsida (Monocotyledons) |
| 585 Pinophyta (Gymnosperms)/Coniferales |
| 586 Cryptogamia (Seedless plants) |
| 587 Pteridophyta (Vascular seedless plants) |
| 588 Bryophyta |
| 589 [unassigned] |
|
| 590 Animals
| 591 Specific topics in natural history |
| 592 Invertebrates |
| 593 Marine & seashore invertebrates |
| 594 Mollusca & Molluscoidea |
| 595 Arthropoda |
| 596 Chordata |
| 597 Cold-blooded vertebrates/Fishes |
| 598 Aves (Birds) |
| 599 Mammalia (Mammals) |
|
