CLASSIFICATION KEY
| Ref | REFERENCE |
| 020 | Preparing books for circulation; Book mending |
| 028 | Selecting books and magazines |
| 100 | PHILOSOPHY |
| 150 | Psychology |
| 170 | Conduct of life; Ethics |
| 200 | RELIGION |
| 220 | Bible; Jesus Christ |
| 291 | Mythology |
| 300 | SOCIOLOGY |
| 326 | Negroes |
| 330 | Economics |
| 331 | Labor and Laboring classes |
| 332 | Money; Banking; Investment |
| 340 | Law and order |
| 350 | Mechanics of government |
| 364 | Penology |
| 368 | Insurance |
| 370 | Education |
| 383 | Stamp collecting |
| 388 | Motor buses |
| 395 | Etiquette |
| 400 | LANGUAGE |
| 423 | Dictionaries |
| 427 | Citizenship for new Americans |
| 428 | Textbooks for foreigners learning English |
| 429 | Easy reading for foreigners learning English |
| 430–490 | Texts for learning foreign languages |
| 500 | SCIENCE |
| 504 | Nature study and essays |
| 510 | Mathematics |
| 520 | Astronomy |
| 530 | Physics |
| 540 | Chemistry |
| 550 | Geology; Weather |
| 570 | Biology |
| 571 | Prehistoric man |
| 575 | Evolution; Heredity |
| 580 | Botany |
| 590 | Zoology |
| 595 | Insects |
| 597 | Fishes |
| 598 | Birds |
| 599 | Animals |
| 600 | USEFUL ARTS |
| 607 | Vocational guidance |
| 608 | Inventions |
| 610–614 | Health, Hygiene and Public safety |
| 620 | Engineering |
| 620.5 | Mechanical drawing; Blueprint reading |
| 621 | Mechanical engineering; Machine shop practice |
| 621.1 | Steam, gas and oil engines |
| 621.3 | Electrical engineering |
| 621.4 | Radio and television |
| 622 | Mining engineering |
| 623 | Ships and shipbuilding; Navigation; Submarines |
| 624 | Civil engineering; Railroads |
| 629 | Automobiles |
| 629.1 | Aeronautics |
| 630 | Agriculture |
| 631 | Fertilizers; Soils |
| 632 | Insect pests and Blights |
| 633 | Field crops |
| 634 | Fruits; Orchards |
| 635 | Gardens, vegetable and flower |
| 636 | Domestic animals; Fur-farming |
| 636.5 | Poultry |
| 637 | Dairying |
| 638 | Bee-keeping |
| 640 | Home Economics |
| 641 | Cookery and food |
| 645 | Furnishing; Home decoration |
| 646 | Clothing; Sewing; Millinery |
| 650 | Business in general; Office methods; Salesmanship; Real estate |
| 653 | Secretarial work; Business letters; Stenography |
| 655 | Printing |
| 657 | Bookkeeping; Accounting |
| 659 | Advertising |
| 671 | Metal working |
| 680 | Mechanic trades; Shop work |
| 682 | Blacksmithing and Forge work |
| 684 | Carpentry |
| 689 | Handicrafts |
| 690 | Building |
| 696 | Plumbing |
| 697 | Heating and Ventilation |
| 698 | Painting and Paperhanging |
| 700 | FINE ARTS |
| 720 | Architecture |
| 740 | Drawing; Lettering; Cartoons |
| 750 | Painting |
| 760 | Block-printing |
