This seventh edition of the LC Classification Outline is almost three times the size of the sixth edition but is less detailed than the outline available on the Cataloging Policy and Support Office web site (*  The purpose of the outline is to provide a key to the Library of Congress classification system greater than just the captions of the subclasses, but less than the full text of the forty-one volumes of the published schedules.  The Outline should contribute to a better understanding not only of the major disciplines but of their breakdowns of topics and subtopics as well.

Since the listing of topics is selective, not exhaustive, gaps in numbering occur at various locations.  These gaps do not necessarily indicate that numbers do not exist.  Gaps often occur at the beginning of a topic, where standard provisions for forms and for some common subtopics are usually omitted.  Additional detail may be found in the outline on the Cataloging Policy and Support Office web site cited above or in the individual schedules themselves.

The Outline is intended for several possible applications.  It is a portable guide for users who wish to browse through book stacks.  It is a condensation that should prove valuable for instructing students in the arrangement of the system.  It helps librarians to purchase the proper schedules required for cataloging their own particular collections.  It furnishes a convenient tool for designing programs to search bibliographic records by classification.  It assists in shelving and in detecting errors in call numbers by indicating the range of numbers in each subclass.

On the other hand, it cannot be used as an abridgement of the system for purposes of simplified classification, as the enumerative nature of the LC classification does not lend itself to compression.

This edition of the Outline was edited by Mary K. D. Pietris, senior cataloging policy specialist, based on outlines originally prepared by Larry Buzard, editor of classification schedules (now retired), for publication in the front of the printed volumes of the classification schedules.

Barbara B. Tillett
Chief, Cataloging Policy and Support Office

April 2003


*  The version of the LC Classification Outline used in this document is from the Cataloging Policy and Support Office web site (

See also:

LC Classification Schedules:  An Outline