How does the Dewey Decimal system work?

The Christchurch City Libraries uses the Dewey Decimal System to classify non-fiction material. Subjects are divided into ten main groups which are represented by series of numbers.

000

General works (including encyclopedias and general reference)

100

Philosophy and psychology

200

Religion

300

Social sciences

400

Languages

500

Sciences

600

Applied sciences / Technology

700

The Arts

800

Literature

900

Geography, history and travel

Each of these ten groups is divided into more specialised subject fields, again represented numerically, for example:

500

Sciences

540

Chemistry

546

Inorganic chemistry

700

The Arts

750

Paintings and painting

751.422

Watercolour technique

Certain features are common to each of the groups, e.g. the first numbers in any area are always general works on that subject and longer numbers represent more detailed aspects.

All non-fiction material is usually shelved in numerical order, according to its assigned Dewey number.

Fiction is shelved alphabetically by author, except fiction in foreign languages.
Fiction in classical languages is classified at 870 – 889. Eg, Virgil, 873.1; Homer, 883.
Fiction from Oceania is classified in 899. Eg, Maori, 899.4423; Tongan, 899.482
Other world language fiction is located by its language code. Eg, Japanese, JPN; Tagalog, TGL

Other points to note are

• There is always a decimal point after the first three numbers
• The three letters which follow the number are usually the first three letters of the author's surname and help to distinguish that particular book from others at the same number
• "NOT FOR LOAN" on the spine indicates a reference book, which may only be used in the library
• "B" on the spine indicates a biography
• "NZ" indicates a New Zealand book
•  The Green Piko Piko symbol indicates Ngā Pounamu Māori collection & Māori collections at Community Libraries
•  White Koru on black label is used on items with Māori content not held in a special Māori collection

The Dewey Decimal Classification is (c) 1996-2001 OCLC Online Computer Library Center, Incorporated. DDC, Dewey, and Dewey Decimal Classification are registered trademarks of OCLC Online Computer Library Center, Incorporated.