Free Cataloging Resources: Classification

This Introduction explains the basic principles and structure of the Dewey Decimal Classification (DDC) system. The Introduction is intended to be used in conjunction with the Glossary and the Manual. The Glossary defines terms used in the Introduction and elsewhere in the Classification. The Manual offers advice on classifying in difficult areas and explains how to choose between related numbers.

The Glossary defines terms used in the Introduction and throughout the schedules, tables, and Manual. Fuller explanations and examples for many terms may be found in the relevant sections of the Introduction. An index to the Introduction and Glossary follows the Glossary.

The Manual offers advice on classifying in difficult areas and explains how to choose between related numbers.

The main structure of the DDC is presented in the DDC Summaries. The first summary contains the ten main classes. The second summary contains the hundred divisions. The third summary contains the thousand sections.

A brief PowerPoint slide show to help you understand how the Dewey Decimal Classification system (DDC) works in libraries. Provided by OCLC.

A brief PowerPoint slide show to help you understand how the Dewey Decimal Classification system (DDC) works in libraries. Provided by OCLC.

Lists the letters and titles of the main classes of the Library of Congress Classification. Click on any class to view an outline of its subclasses.

This page provides print-ready PDF files of Library of Congress classification schedules. Data for these files was selected in May 2024.

The purpose of this publication is to provide guidelines for establishing Library of Congress classification numbers and assigning them to library materials, as well as for shelflisting materials collected by the Library of Congress. The work is not intended to be a comprehensive work on classification and shelflisting theory nor an exhaustive explanation of the Library of Congress classification and shelflisting system. Rather, it is an accumulation of guidelines that have been formulated over several decades dealing with commonly recurring questions that arise when using the LC classification.

A short Cutter table (taken from Classification and Shelflisting Manual instruction sheet G 63) for use as a guide.

List of Library of Congress Cutter Numbers for geographic locations.

Find information about the Dewey Cutter Program, a software program that automatically provides cutter numbers from the OCLC Four-Figure Cutter Tables (Cutter Four-Figure Table and Cutter-Sanborn Four-Figure Table) upon input of text. It works with most Windows versions, and enhances your classification efficiency. It does not work with Macintosh computers.

OCLC has developed an online set of training materials for the DDC focused on the needs of experienced librarians who need Dewey application training. The materials include modules on general principles governing the operation of the DDC as well as modules on the structure and use of specific tables and main classes.

This technical introduction explains DDC's use of structural and notational hierarchy, different types of notes in the DDC, explains the relationship of different terminologies to the DDC, shows how to apply basic rules to choose correctly between multiple potential base numbers, and how to apply basic number building techniques.

In this YouTube video from OCLC, learn about the fundamental principles of the DDC as well as practical strategies for efficient navigation and searching of WebDewey.