Note: Call numbers that begin with A, B, and C should be substituted with these numbers: A = 016., B = 920., and C = 380.

Call numbers appear in two ways:

621.306 or 621.306W727h
W727h

Follow these basic principles in reading Dewey Decimal call numbers:

• Any numerals that appear behind the decimal are read as decimal numbers. For example:
  • 623.3 comes before
  • 623.306 followed by
  • 623.35 followed by
  • 623.4 etc.
• When a number follows a letter, read it as in the following example. For example:
  • 623.306 W72 comes before
  • 623.306 W727 and would come before
  • 623.306 W75 and before
  • 623.306 W8
• A lower case letter may follow, adding another layer of alphabetical order.

Note: When there is no decimal point, items are shelved in this order:

• 623 W72
• 623.1 A12h
• 623.1 A8h

004 Data Processing; Computer Science
004.21 Systems analysis and design
004.22 Computer architecture
004.5 Storage
004.6 Interfacing and communications
004.65 Computer networks
004.7 Peripherals
005 Computer programming, programs, data
005.1 Programming
005.131 Symbolic logic
005.133 Specific programming languages
005.4 Systems programming
005.43 Operating systems
005.71 Data communications
005.73 Data structures
005.74 Data files and databases
005.8 Data security

006 Special computer methods
006.3 Artif. intelligence [also 001.535]
006.4 Pattern recognition
006.5 Computer sound synthesis
006.6 Computer graphics

384 Communications/Telecommunication
384.3 Computer communication
384.51 Wireless communication

510 Mathematics
511 General principles of mathematics
512 Algebra
513 Arithmetic
514 Topology
515 Analysis (515.15 Calculus and analytic geometry)
516 Geometry
518 Numerical analysis
519 Probabilities and applied mathematics

520 Astronomy & allied sciences
521 Celestial mechanics
522 Techniques, equipment, materials
523 Specific celestial bodies & phenomena
524 Not assigned or no longer used
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 Gas mechanics
534 Sound & related vibrations
535 Light & paraphotic phenomena
536 Heat
537 Electricity & electronics
538 Magnetism
539 Modern physics

551 Geology, hydrology, meteorology
551.01 Philosophy and theory of geology
551.09 History, geographic treatment, biography of geology
551.1 Gross structure and properties of the earth
551.2 Volcanoes, earthquakes, thermal waters and gases
551.3 Surface and exogenous processes and their agents
551.4 Geomorphology and hydrosphere
551.5 Meteorology
551.6 Climatology and weather
551.7 Historical geology
551.8 Structural geology
551.9 Geochemistry

620 Engineering and allied operations
620.1 Mechanics and materials
620.11 Materials science
620.106 Applied fluid mechanics
620.2 Sound and related vibrations
620.3 Mechanical vibration
620.8 Human-factors/safety engineering

621 Applied physics
621.04 Energy and plasma engineering
621.1 Steam engineering
621.2 Hydraulic-power technology
621.3 Electronics, magnetics, communications, computer engineering, lighting
621.39 Computer engineering
621.8 Machine engineering

622 Mining and related operations
622.1 Prospecting /exploratory ops.
622.2 Excavation techniques
622.4 Mine environment
622.5 Mine drainage
622.6 Mine transport systems
622.7 Ore dressing
622.8 Mine health and safety

623 Military and nautical engineering
623.1 Fortifications
623.2 Mine laying, demolition
623.3 Engineering of defense
623.4 Ordnance
623.5 Ballistics and gunnery
623.6 Military transportation technology
623.7 Commun., vehicles, sanitation
623.8 Nautical engineering

624 Civil engineering
624.1 Structural engineering
624.151 Engineering geology
624.2 Bridges
624.3 Specific types of bridges
624.4 Tubular and box-girder bridges
624.5 Suspension bridges
624.6 Arch bridges
624.7 Compound bridges
624.8 Movable bridges

625 Engineering of railroads, roads, highways
625.1 Railroads
625.2 Railroad rolling stock
625.3 Inclined, mountain, ship railroads
625.4 Rapid transit systems
625.5 Cable and aerial railways
625.6 Surface rail and trolley systems
625.7 Roads
625.8 Artificial road surfaces

627 Hydraulic engineering
627.1 Inland waterways
627.2 Harbors, ports, roadsteads
627.3 Port installations
627.4 Flood control
627.5 Reclamation, irrigation
627.7 Underwater operations
627.8 Dams and reservoirs
627.9 Other hydraulic structures

628 Sanitary and municipal engineering
628.1 Water supply
628.2 Sewers and sewage
628.3 Sewage treatment and disposal
628.4 Waste technology
628.5 Industrial sanitation engineering
628.7 Rural sanitary engineering

629 Other branches of engineering
629.04 Transportation engineering
629.1 Aerospace engineering
629.2 Motor land vehicles and cycles (Automotive engineering)
629.4 Astronautics
629.8 Automatic control engineering

660 Chemical engineering
660.6 Biotechnology
660.62 Industrial microbiology
660.63 Biochemical engineering
660.65 Genetic engineering
660.7 Industrial stoichiometry
661 Technology of industrial chemicals

662 Explosives, fuels, related products
662.1 Fireworks (Pyrotechnics)
662.2 Explosives
662.4 Detonators
662.5 Matches
662.6 Fuels
662.7 Coke and charcoal
662.8 Other fuels
662.9 Nonfuel carbons

665 Industrial oils, fats, waxes, gases
665.5 Petroleum
665.7 Natural gas/Manufactured gases

666 Ceramic and allied technologies
666.1 Glass
666.7 Refractories and structural clay
666.8 Synthetic and artificial minerals
666.893 Concrete
666.9 Masonry adhesives

668 Technology of other organic products
668.4 Plastics (see also 547.8432)

669 Metallurgy
669.1 Ferrous metals
669.2 Precious, rare-earth metals
669.3 Copper
669.4 Lead
669.5 Zinc and Cadmium
669.6 Tin
669.7 Other nonferrous metals
669.9 Physical and chemical metallurgy

670 Manufacturing
670.427 Computer-aided manufacture

671 Metalworking processes and primary metals
671.2 Foundry practice (casting)
671.3 Mechanical working

672 Iron, steel, other iron alloys

673 Nonferrous metals
673.2 Precious, rare-earth metals
673.3 Copper
673.4 Lead
673.5 Zinc and cadmium
673.6 Tin
673.7 Other nonferrous metals
673.71 Mercury
673.722 Aluminum

674 Lumber processing, wood products cork

676 Pulp and paper technology

678 Elastomers and elastomer products
678.2 Rubber
678.5 Latexes

680 Manufacture of products for specific uses

681 Precision instruments and other devices

690 Buildings

691 Building materials
691.1 Timber
691.2 Natural stones
691.3 Concrete and artificial stones
691.4 Ceramic and clay materials
691.5 Masonry adhesives
691.6 Glass
691.7 Iron and steel (ferrous metals)
691.8 Metals
691.9 Other building materials
691.92 Plastics and their laminates

692 Auxiliary construction practices
692.3 Construction specifications

693 Construction – Specific Topics
693.1 Masonry
693.2 Stabilized earth materials
693.3 Tiles and terra cotta
693.4 Artificial stones and hollow bricks
693.5 Concrete
693.6 Plaster, stucco, lathwork
693.7 Metals
693.8 Construction for specific purposes
693.852 Earthquake resistant construction

694 Wood construction, carpentry
694.1 Planning, analysis, design

695 Roof covering

696 Utilities
696.1 Plumbing

697 HVAC
697.1 Radiative heating
697.2 Convective heating
697.3 Hot-air heating
697.4 Hot-water heating
697.5 Steam heating
697.7 Other heating methods
697.9 Ventilation and air conditioning