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Dewey® Services

Mapping new LCSH with DDC numbers

In 2006, we suspended mapping new Library of Congress Subject Headings (LCSH) to suggested Dewey Decimal Classification® (DDC) numbers to make room for a project to add DDC numbers to the authority records for BISAC (Book Industry Standards and Communications) subject headings.

You can browse new Library of Congress Subject Headings with suggested DDC numbers for recent topics that are not explicitly mentioned in the current edition of the DDC system. The Dewey editorial team selects LCSHs from recent Weekly Lists that are accompanied by candidate numbers from the current DDC edition. The list of DDC numbers is not exhaustive, and you should also consult the DDC schedules and tables before applying a number from the lists.

These lists of LCSHs were selected from recent Weekly Lists accompanied by candidate DDC numbers from Edition 22. Beginning with Weekly Lists 2004, the headings selected include all LCSHs originally recommended by non-U.S. libraries (with the exception of family names). The headings from non-U.S. libraries are marked with an asterisk (*). The purpose of the lists is to provide classifier assistance for topics of recent interest not mentioned explicitly in Edition 22. The DDC numbers listed are not exhaustive, and the schedules and tables should be consulted before applying a number from the lists.

Browse the archive of LCSH postings since 2003.

Thank you for your interest in the DDC. Ongoing access to all updates to the DDC and to the complete list of LCSH/DDC postings is available through WebDewey® services.


The Dewey Decimal Classification (DDC) system is the world’s most widely used way to organize library collections. The DDC constantly updates to enable better discovery across any topic in multiple languages. Because the DDC is easy to use, you can increase the visibility of your materials quickly and efficiently.

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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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