Tag of the Month

Category: Tag of the Month Bibliographic Archives
Title: 020 - International Standard Book Number (R)

The 020 tag of the MARC bibliographic format contains the 
International Standard Book Number (ISBN), terms of 
availability, and any canceled or invalid ISBN related to the item. 

AACR2 covers standard numbers and terms of availability in rule 
1.8 and in the X.8 subsection in each chapter (2.8, 3.8, etc.).  RDA
provides instructions on recording identifiers (ISBNs) in 2.15 and terms
of availability in 4.2.1. Although originally created for books, ISBNs 
can be found in all formats except manuscripts. 

The International Standard Book Number consists of ten or 
thirteen digits. The ten digit ISBN is made up of four parts: 
Group identifier, Publisher identifier, Title identifier, 
and Check digit. The Group identifier, Publisher identifier, 
and Title identifier make up the first nine digits of
the ISBN. The Check digit is the tenth digit. 

The thirteen digit ISBN consists of five elements. Element one
consists of a 3-digit EAN prefix that identifies the book
industry. The second element identifies the country or
language agency.  Element three identifies the publisher
prefix.  The fourth element identifies the titles or specific
edition and the fifth element contains a check digit.
             Note: Some older books have SBNs. These can be turned 
             into ISBNs by adding the Group identifier, if known, 
             to the beginning of the number. 

A valid ISBN is entered in subfield a of tag 020 and can be qualified 
with information about the binding, format, volume numbers, part of a 
set, publisher, distributor, etc. Qualifying information is entered in 
subfield q.  RDA provides guidelines for recording the 
qualifying information with examples showing this data enclosed in 
parenthesis. An invalid or canceled ISBN and its qualifiers is entered
in subfield z. Tag 020 is repeatable, and each SBN must have its own 
020 tag. 

Terms of availability (usually price) are recorded in subfield c.  A price 
may be recorded in subfield c even when no ISBN is available for 
the item. 


First  Undefined

   blank Undefined

Second  Undefined

   blank Undefined

     a International Standard Book Number (NR) 

     c Terms of availability (NR) 

     q Qualifying information (R)

     z Canceled or invalid ISBN (R) 


Books with qualifying information in subfield q

(There is a discrepancy between how the qualifying data
is entered in subfield q in the MARC 21 documentation and
how it is entered following the RDA guidelines. MARC 21 shows
the data without parenthesis; RDA shows the data enclosed in
parenthesis. The Library of Congress and cataloging agencies
are following the RDA guidelines)

     020     _a9780345532749_qtrade  (MARC 21 format example)

     020     _a9780345532756_q(ebook) (RDA example)

Destiny currently automatically adds parenthesis around this data
when displaying it. Thus, double parenthesis will display if the data 
is entered enclosed in parenthesis as the RDA example shows.

Book in cloth and paperback bindings with prices in U.S. and 
Canadian dollars

     020    _a0590582475 :
               _c$12.95 ($17.99 Can.)
     020    _a0590205153 (pbk.) :
               _c$4.95 ($5.95 Can.)

Book with different ISBNs for each distributor

     020    _a0802850731 (Eerdmans) 
     020    _a0865433771 (Africa World Press)

Book with price but no ISBN

     020    _c$5.95 (pbk.)

Book that has both valid and invalid or canceled ISBNs 
on verso of title page

     020    _a0397319924
     020    _z0397318487

Book printed on permanent paper

     020    _a9780060723804 (alk. paper)

ISBNs for set as well as for individual volumes

     020    _a0810392070 (set : acid-free paper)
     020    _a0810392119 (v. 1 : acid-free paper)
     020    _a0810392097 (v. 2 : acid-free paper)
     020    _a0810392100 (v. 3 : acid-free paper)

Computer program disk with an ISBN

     020    _a0874904099 :
               _c$49.00 ($55.00 for 3 1/2 in. disk)