http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
MARC twenty-one format for classification data
Network Development and MARC Standards Office,
This online publication provides access to both the full and concise versions of the MARC 21 Format for Classification Data. The "full" classification format contains detailed descriptions of every data element, along with examples, input conventions, and history sections. The "concise" classification format contains abridged descriptions of every data element, along with examples. The full and concise versions are identified in the header of each field description.
Online versions of both the full and concise MARC formats were made available in 2008, when it was determined by the Library of Congress that the online versions would be the version of record, and the print a byproduct produced after the online version. The Network Development and MARC Standards Office ceased producing the full format in print in 2011--MARC listserv, June 1, 2011.
GPO Cataloging Record Distribution Program (CRDP).
MARC 21 concise format for classification data