Organize your materials with the world's most widely used library classification system.
The Dewey Decimal Classification (DDC) system is the world’s most widely used library classification system. The 23rd edition of the DDC enhances the efficiency and accuracy of your classification work in ways no previous editions have done.
You can use the DDC in several convenient formats. The four-volume print edition includes thousands of updates added to the system over the past seven years. The electronic version, WebDewey, enhances the print updates with online delivery that is updated continuously. Abridged Edition 15 is a simplified version perfect for smaller collections. Whether you choose the print or electronic format (or both), DDC 23 makes it easier than ever to organise your library collections.
The DDC evolves continually to keep up with recorded knowledge. You can find news about DDC developments in several ways, including a semiannual DDC newsletter, DDC conferences and workshops, OCLC Newsletter articles and case studies.
All copyright rights in the Dewey Decimal Classification system are owned by OCLC.
Dewey, Dewey Decimal Classification, DDC, OCLC and WebDewey are registered trademarks of OCLC.
Organize your collection
Libraries big and small the world over use the Dewey Decimal Classification (DDC) to help make sense of today's complex library collections. The DDC is available in both print and web formats, and in full and abridged editions.
Break down language barriers
The DDC system has been translated into more than 30 languages and serves library users in over 200,000 libraries in 135+ countries worldwide, making it the world's most widely used library classification system. More than 60 of these countries use the DDC to organize their national bibliographies.
“Dewey is a quick way to give our patrons a place to start to browse on the shelves and uncover resources not detected through a simple catalog search.”
Oaklyn Branch Library
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Learn more about organizing your materials with the world's most widely used library classification system.
The Dewey blog is a great source for news and views on classification issues, as well as interesting and unusual DDC resources and curiosities. It's also a convenient way to share feedback directly to the DDC editors to help shape the future of the DDC.
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All copyright rights in the Dewey Decimal Classification system are owned by OCLC. Dewey, Dewey Decimal Classification, DDC, OCLC and WebDewey are registered trademarks of OCLC.