There are two practices that have been applied at the Library of Congress. The most common is a situation in which the treatment of the series is changed during its life span. Part of the series may be collected under a call number while earlier or later issues are classified separately. This may be due to changes in the publications (e.g., analyzable titles no longer appear on the issues (see CCM 12.6.3.)), or changes in LC policies regarding the cataloging of series. Such decisions are reflected in the series authority record and may also be reflected in the cataloging record. In the SAR there may be two 646 fields showing the different treatments and the numbers or dates of issues involved. A note may be given in the cataloging record (field 500, formerly 512).

The second situation is one which is no longer practiced. Under this policy, several "sets" or copies of the serial were retained in the Library, one in a collected set and the other(s) classified separately. This practice was referred to as "split treatment." While many of the series originally treated in this manner have been changed to "classed separately, analyzed in full," SARs may still be found with split treatment decisions. Example:

See also:

12.7. LC practices regarding changes in treatment