ETL 505 Module 5 Entries and Tables in DDC

Entries in the schedules and tables are composed of a DDC number in the number column (the column at the left margin), a heading describing the class that the number represents, and often one or more notes. DDC numbers are listed in groups of three digits for ease of reading and copying. All entries (numbers, headings, and notes) should be read in the context of the hierarchy.

The first three digits of schedule numbers (main classes, divisions, sections) appear only once in the number column, when first used. They are repeated at the top of each page where their subdivisions continue. Subordinate numbers appear in the number column, beginning with a decimal point, with the initial three digits understood.

Table numbers are given in full in the number column of the tables, and are never used alone.

There are six numbered tables in DDC 23:

T1 Standard Subdivisions

T2 Geographic Areas, Historical Periods, Biography

T3 Subdivisions for the Arts, for Individual Literatures, for Specific Literary Forms

T3A Subdivisions for Works by or about Individual Authors

T3B Subdivisions for Works by or about More than One Author

T3C Notation to Be Added Where Instructed in Table 3B, 700.4, 791.4, 808–809

T4 Subdivisions of Individual Languages and Language Families

T5 Ethnic and National Groups

T6 Languages

Except for notation from Table 1 (which may be added to any number unless there is an instruction in the schedules or tables to the contrary), table notation may be added only as instructed in the schedules and tables

Some numbers in the schedules and tables are enclosed in parentheses or square brackets.

Numbers and notes in parentheses provide options to standard practice. Numbers in square brackets represent topics that have been relocated or discontinued, or are unassigned. Square brackets are also used for standard subdivision concepts that are represented in another location. Bracketed numbers should never be used.

Standard subdivisions are also bracketed under a hook number, that is, a number that has no meaning in itself, but is used to introduce specific examples of a topic. Hook numbers have headings that begin with “Miscellaneous,” “Other,” or “Specific”; and do not contain add notes, including notes, or class-here notes. For example:

652.302 Specific levels of skill

[.302 01–.302 09] Standard subdivisions

Do not use; class in 652.3001–652.3009


ETL 505 Module 5 Intro to DDC

The ten main classes are:

000 Computer science, information & general works

100 Philosophy & psychology

200 Religion

300 Social sciences

400 Language

500 Science

600 Technology

700 Arts & recreation

800 Literature

900 History & geography


Class 000 is the most general class, and is used for works not limited to any one specific discipline, e.g., encyclopedias, newspapers, general periodicals. This class is also used for certain specialized disciplines that deal with knowledge and information, e.g., computer science, library and information science, journalism. Each of the other main classes

(100–900) comprises a major discipline or group of related disciplines.

Class 100 covers philosophy, parapsychology and occultism, and psychology.

Class 200 is devoted to religion.

Class 300 covers the social sciences. Class 300 includes sociology, anthropology, statistics, political science, economics, law, public administration, social problems and services, education, commerce, communications, transportation, and customs.

Class 400 comprises language, linguistics, and specific languages. Literature, which is arranged by language, is found in 800.

Class 500 is devoted to the natural sciences and mathematics.

Class 600 is technology.

Class 700 covers the arts: art in general, fine and decorative arts, music, and the performing arts. Recreation, including sports and games, is also classed in 700.

Class 800 covers literature, and includes rhetoric, prose, poetry, drama, etc. Folk literature is classed with customs in 300.

Class 900 is devoted primarily to history and geography. A history of a specific subject is classed with the subject.

Since the parts of the DDC are arranged by discipline, not subject, a subject may appear in more than one class. For example, “clothing” has aspects that fall under several disciplines. The psychological influence of clothing belongs in 155.95 as part of the discipline of psychology; customs associated with clothing belong in 391 as part of the discipline of customs; and clothing in the sense of fashion design belongs in 746.92 as part of the discipline of the arts.


Arabic numerals are used to represent each class in the DDC. The first digit in each three-digit number represents the main class. For example, 500 represents science. The second digit in each three-digit number indicates the division. For example, 500 is used for general works on the sciences, 510 for mathematics, 520 for astronomy, 530 for physics. The third digit in each three-digit number indicates the section. Thus, 530 is used for general works on physics, 531 for classical mechanics, 532 for fluid mechanics, 533 for gas mechanics. The DDC uses the convention that no number should have fewer than three digits; zeros are used to fill out numbers.

A decimal point, or dot, follows the third digit in a class number, after which division by ten continues to the specific degree of classification needed. The dot is not a decimal point in the mathematical sense, but a psychological pause to break the monotony of numerical digits and to ease the transcription and copying of the class number. A number should never end in a 0 anywhere to the right of the decimal point.

Notational hierarchy

Notational hierarchy is expressed by length of notation. Numbers at any given level are usually subordinate to a class whose notation is one digit shorter; coordinate with a class whose notation has the same number of significant digits; and superordinate to a class with numbers one or more digits longer. The underlined digits in the following example demonstrate this notational hierarchy:

600 Technology (Applied sciences)

630 Agriculture and related technologies

636 Animal husbandry

636.7 Dogs

636.8 Cats

“Dogs” and “Cats” are more specific than (i.e., are subordinate to) “Animal husbandry”; they are equally specific as (i.e., are coordinate with) each other; and “Animal husbandry” is less specific than (i.e., is superordinate to) “Dogs” and “Cats.”

Classifying with DDC

The guiding principle of the DDC is that a work is classed in the discipline for which it is intended, rather than the discipline from which the work derives. This enables works that are used together to be found together. For example, a general work by a zoologist on agricultural pest control should be classed in agriculture, not zoology, along with other works on agricultural pest control.

The First-of-Two Rule

If two subjects receive equal treatment, and are not used to introduce or explain one another, class the work with the subject whose number comes first in the DDC schedules. This is called the first-of-two rule. For example, a history dealing equally with the United States and Japan, in which the United States is discussed first and is given first in the title, is classed with the history of Japan because 952 Japan precedes 973 United States.

Sometimes, specific instructions are given to use numbers that do not come first in the schedules. For example, at 598, the note “class comprehensive works on warm-blooded vertebrates in 599” tells the classifier to ignore the first-of-two rule and class a work on birds (598) and mammals (599) in 599, which is the comprehensive number for warm-blooded vertebrates.

Also disregard the first-of-two rule when the two topics are the two major subdivisions of a subject. For example, collection systems (628.142) and distribution systems (628.144) taken together constitute 628.14 Collection and distribution systems. Works covering both of these topics are classed in 628.14 (not 628.142).


ETL 505 Module 5 Classification

Classification and School Libraries

  • Systematic arrangement
  • Support browsing, filtering and retrieval of bibliographic information in online systems but not often used for this
  • Classification codes are a form of controlled indexing language
  • Classification process  similar to subject vocabulary indexing, Classifier must consider what it’s about and label the concept
  • Language instead is notation -numerical/alphanumerical symbols
  • Classification codes are even more unfamiliar to users than controlled languages
  • Another difference is that classifiers typically try to describe the subject of an information resource using one classification
  • Classification codes can express more complex subjects than most alphabetic indexing languages
  • Similarity between classification schemes and pre-coordinated indexing languages (eg. subject headings lists)
  • Detailed subject description useful in matching user need
  • Classification codes though for the library specialist!

Classification as a Locating Device

  • For locating purposes of specific works and to group like together
  • Purpose of collection affecting method of classification
  • Predominantly grouped by subjects
  • Different types of arrangement are frequently used in conjunction with subject; fiction – author; genre; series; format
  • Other classifications: by language; format; rarity; sensitive/offensive material; special subject collections; special collections (eg. material requested to be kept together)
  • Libraries concerned with providing information hence subject arrangement helps
  • If based on already known items title and author would make sense


Is Classification Helpful?

  • In classifying thoroughly using dewey some items are grouped together but others moved apart
  • If searching for something else, resources could be scattered everywhere over the shelves!
  • Hence the catalogue is of importance in considering limits of the shelf arrangement

Choosing a Classification Scheme

  • Determined by which ones are available on a bibliographic/cataloguing network (eg. SCIS)
  • Dewey Decimal Classification usually but large academic libraries sometimes the Library of Congress Classification
  • Advantages: kept up to date; familiar world-wide; easily accessible and workable through MARC, cataloguing services, etc.; history of working!
  •  Universal Decimal Classification more specific (scientific and technical subjects)
  • Specialist subject libraries may used specialist classifications
  • So too formats (maps and atlases Boggs and Lewis)

Dewey Decimal Classification

  • Advantages: include has organisational support; is regularly revised; full and abridged editions
  • Disadvantages of cultural bias; some sections crowded (eg. technology); base 10 limits concepts expressed; long notation
  • Discipline (fields of study) based therefore, subject might appear in a number of classes in the scheme depending on context
  • 10 classes – 10 divisions each class – 10 sections each division
  • First digit in three the class, second the division, and third the section
  • Never 0 in ending a number on the right of the decimal point
  • Applying DDC requires determining subject, disciplinary focus, perhaps approach or form
  • Author’s intent when considering subject
  • Classed in discipline of intention rather than discipline from which derived
  • Class – subject being acted upon
  • The increasingly availability of DDC classification numbers for resources = new emphasis from creating a classification number to ensuring that the classification number assigned fits the classification needs, standards and practices of the library
  • DDC tablesTable 1 Standard SubdivisionsTable 2 Geographic Areas, Historical Periods, Biography

    Table 3A-C Subdivisions for Arts, for Individual

    Literatures, for Specific Literary Forms

    Table 4 Subdivisions of Individual Languages and

    Language Families

    Table 5 Ethnic and National Groups

    Table 6 Languages

Using Webdewey

Hints from annotated powerpoint

  • Home tab top right in starting over a new search re. WebDewey
  • Book icon signals reference to the manual
  • puzzle piece means it is already a built number
  • Be thorough with number bulding or you might miss something!
  • Make sure you refer to the notes
  • Can use truncation, boolean search techniques, and masking (ie. ? or # e.g. wom?n; col#r) with WebDewey Advanced Search but not with Browsing
  • Browse to see if a term exists or to find alternative terms
  • Browse useful in combination with the relative index
  • Decisions about the use of table depending on the format, language, and subject treatment of your item
  • Table 1 will examine format of your resource (standard subdivisions)
  • If you cant find a built number to fit your item, you will need to build it yourself by using the search function, relative index, and then reading the notes

DDC and School Libraries

  • Since the 1980s SCIS continues to adopt and apply the two current editions of Dewey Decimal Classification as its classification tools for Australian and New Zealand school libraries
  • The two editions used are the full edition (DDC23/WebDewey 2.0) and the abridged edition (ADDC15/Abridged WebDewey)
  • By providing classification numbers from both the full and abridged choice based on need is recognised
  • Most primary/elementary school libraries use the abridged version as do many secondary school libraries ( abridged version is rarely used outside school libraries actually)
  • SCIS makes adaptions and amendments to the Dewey Decimal Classification to make it more suitable to the needs of school libraries. These changes are given in SCIS standards for cataloguing and data entry, Section 3, Classification

DDC and SCIS Standards

  • SCIS has chosen to make specific rulings on the use of DDC tools and certain local adaptations to them, in order to make them more appropriate to the particular needs of Australian and New Zealand school libraries
  • SCIS decisions on and adaptations to both editions of DDC are documented in SCIS standards for cataloguing and data entry, Section 3, Classification
  • Structured as an introduction (3:C), general principles (3:D) and specific decisions on how SCIS interprets and adapts DDC (3:E)
  • Be wary. Some statements of principle, or policy, are given in 3:C while 3:D contains some specific decisions
  • Classifier needs to have a good knowledge of all three parts
  • SCIS records shouid include 2 numbers (except for fiction) – one from ADDC15 and one from DDC23
  • “cataloguing decisions are more significant than classification for information retrieval purposes” – hmmmmmmm. Is not the primary purpose of cataloguing to aid information retrieval?
  • “If access via the alphabetical catalogues can be assured, then fine subdivisions of Dewey classes or ingenious shelving devices are not especially valuable ways of linking related materials” more hmmmmmmmmmmmmm
  • Call numbers in the database and SCIS products do not include prefixes or location symbols
  • The policy is to class fiction, regardless of language, as ‘F’
  • LOTE materials treated in the same way as materials in English
  • In shelving LOTE materials in separate sequences, libraries need to supply their own prefixes or location symbols
  • 3:C4 and 3:C6 bypass 3:D leading directly to 3:E – significant policies to be aware of
  • Purpose of system policy is to reduce the diversity in order to promote consistent practice
  • For effectiveness the appropriateness of a given number should always be checked upward through each succeeding level of the hierarchy
  • SCIS Standards limit the number-building allowed by DDC23 and ADDC15
  • Full edition 9 digits with 6 after the decimal point
  • Cataloguers will always test the adequacy of a seven (ADDC15) – or nine-digit number before proceeding further
  • When adding from Table 2 in classes other than history and geography, add only the notation from the country and not its state or regional subdivisions, for all countries except Australia and New Zealand
  • Using T2 avoid adding one area notation to another following instructions such as ‘Add notation 3–9; then … add 0 and to the result add notation 3–9 …’, unless a special decision to do so is recorded in 3:E
  • Using T3 ignore all instructions to add from Table 3-C. This supplementary table is used for reference purposes only
  • T4 cataloguers will limit expansion by ignoring all instructions given in Table 4: Subdivisions of Individual Languages to ‘Add to [Table 4] notation 1–9 (or 2–9) from Table 6’
  • T5/T6 no special limiting rules
  • T1 Cataloguers will follow carefully the guidelines set out in section 8.3-8.10 of the Introduction and the interpretations and instructions given in the Manual
  • Avoid using T1–09 + T2 notation where the base number is already seven digits