The Library of Congress classifies many monographic series and multipart items as collected sets, i.e. all of the individual analytics are assigned the same classification number and shelved together. Many libraries who use LC cataloging records prefer to classify and shelve each analytic separately. As a service to these libraries, LC provides in its cataloging records for these titles both the LC collected set number and an alternate classification number based on the contents of the individual work. The latter number is not used to shelve LC’s own copy(ies) of the work (except in the case of special alternate numbers created for works assigned to and shelved in the Geography and Map Division’s atlas collection).


1. When to assign and when to omit the alternate number

2. Selecting and formulating the alternate number

3. Providing the alternate number for the shelflister

See also:

Alternate Class Numbers