Library of Congress Classification:

The Library of Congress Classification (LCC), being a system originally and specifically designed for the Library's own collection, generally eschews alternatives. Within the LCC schedules, alternatives are found occasionally in earlier editions; there are no alternative numbers in recently developed or revised schedules. On the other hand, many alternative numbers representing different treatment of specific types of materials such as bibliographies and monographic series are provided in LC MARC records. Such numbers may be used by other libraries that prefer the alternative weatmenl. In addition, many LC MARC records also include class or call numbers based on other classification schemes, including the Dewey Decimal Classification (DDC), the National Library of Medicine Classification (NLM), and the Superintendent of Documents Classification. The alternative class numbers assigned from other classification systems are provided as services to libraries not using the Library of Congress Classification.