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020  International Standard Book Number (R)

Input Standards

Required if applicable/Required if applicable
1st Indicator  Undefined
blank character Undefined
2nd Indicator  Undefined
blank character Undefined
Subfields (R=Repeatable  NR=Nonrepeatable) Input Standards
‡a International Standard Book Number (NR) Required if applicable/Required if applicable
‡c Terms of availability (NR) ALL except SCO: Do not use/Do not use
‡c Terms of availability (NR) SCO: Optional/Optional
‡q Qualifying information (R) Required if applicable/Required if applicable
‡z Canceled/invalid ISBN (R) Required if applicable/Required if applicable


Contains the International Standard Book Number (ISBN). Use for canceled ISBNs, invalid ISBNs, SBNs, and terms of availability.

An ISBN is a unique number assigned to an item by its publisher. Each ISBN is a 10- or 13-digit number and has four parts: the language group of the country of publication, the publisher, the title, and the check character.

Thirteen-digit ISBNs must begin with either 978 or 979 (a 13-digit EAN beginning with 978 or 979 may be input as a valid ISBN).

If printed in a book, catalog, or bibliography, these four parts are usually separated by hyphens, periods, or spaces. Do not enter the hyphens, periods, or spaces.

Note: If the final character is a lowercase x, enter an uppercase X.

Entering multiple ISBNs

Use the following guidelines for entering multiple ISBNs:

  • Enter each valid ISBN in a separate 020 field.
  • Invalid ISBNs may be entered in a single 020 field with repeated subfields ‡z; however, OCLC recommends entering each invalid ISBN in a separate 020 field.
  • If a book has ISBNs for both hard cover and paperback editions and if the publishers are the same, enter each ISBN in a separate 020 field.
020     0198702337 ‡q (hbk.)
020     0198702345 ‡q (pbk.)
  • If you are cataloging a single part of a multipart item, enter both the numbers for the part and the set when available. Enter the number for the part first.
020     0379005514 ‡q (volume 1)
020     0379005506 ‡q (set)
  • If you are cataloging a multipart item, enter both the numbers for the set and the individual parts when available. Enter the number for the set first.
020     0415364221 ‡q (set ; ‡q alk. paper)
020     9780415364225 ‡q (set ; ‡q alk. paper)
020     041536423X ‡q (v. 1 ; ‡q alk. paper)
020     9780415364232 ‡q (v. 1 ; ‡q alk. paper)
020     0415364248 ‡q (v. 2 ; ‡q alk. paper)
020     9780415364249 ‡q (v. 2 ; ‡q alk. paper)
020     0415364256 ‡q (v. 3 ; ‡q alk. paper)
020     9780415364256 ‡q (v. 3 ; ‡q alk. paper)
Standard Book Numbers

Some items contain Standard Book Numbers. They are the forerunner of modern ISBNs and are nine digits in length. If the item was published in Australia, Canada, New Zealand, South Africa, the United Kingdom, the United States, or Zimbabwe, enter an initial 0 before the Standard Book Number (SBN). Enter the SBN in subfield ‡a. Enter SBNs from other countries in subfield ‡z.

For example, if the SBN is 717803139, enter:


The final character of an ISBN is a calculated check character, either 0-9 or X. It is used to identify and eliminate typographical errors.

When you validate a record containing field 020, the system checks subfield ‡a to verify that the content and length of the ISBN are correct and that the check character matches the calculated check character.

If there is an error in the ISBN (e.g., it is too long or too short, has an incorrect character in any position, or an incorrect value in the check digit), the system displays an error message with the ISBN remaining in subfield ‡a. If you made a typographical error, correct the ISBN and validate the record again. If the error message appears again and you transcribed the ISBN exactly, the ISBN is in error. Enter the ISBN in subfield ‡z.

Deleting ISBNs

If a record contains corresponding 10- and 13-digit ISBNs and you delete one, the system will regenerate the one you deleted and add it to the record. To avoid this situation, delete both ISBNs when editing locally.

1st Indicator

Undefined. The 1st indicator position is undefined and contains a blank ( blank character ).

blank character


2nd Indicator

Undefined. The 2nd indicator position is undefined and contains a blank ( blank character ).

blank character



‡a International Standard Book Number

Enter the 10- or 13-digit International Standard Book Numbers into subfield ‡a. OCLC systems automatically generate a corresponding 10- or 13-digit ISBN if not already present in the record.

020     0842270884
020     9780842270885
020     0700014586 ‡q (paperback)
020     9780700014583 ‡q (paperback)
‡c Terms of availability

Do not enter any price information. Generally do not enter terms of availability. For scores you may use subfield ‡c to indicate the availability of rental material.

020     0460044524 : ‡c Rental material
020     9780460044523 : ‡c Rental material
‡q Qualifying information

A brief statement of qualifying information concerning the item associated with a number being recorded in subfield ‡a or subfield ‡z.

Prior to the definition of subfield ‡q in 2013, qualifying information was contained in subfield ‡a and subfield ‡z.

020     0893571121 ‡q (pbk. ; ‡q v. 1)
020     9780893571122 ‡q (pbk. ; ‡q v. 1)
020     089357113X ‡q (pbk. ; ‡q v. 2)
020     9780893571139 ‡q (pbk. ; ‡q v. 2)
020     1100216243 ‡q (electronic bk.)
020     9781100216249 ‡q (electronic bk.)
020     0061435163 ‡q (sound recording ; ‡q OverDrive Audio Book)
020     9780061435164 ‡q (sound recording ; ‡q OverDrive Audio Book)
‡z Canceled/invalid ISBN

ISBNs can be invalid in two ways:

  • Structurally invalid:
    • ISBNs whose check character does not agree with the calculated check character are invalid.
    • ISBNs that do not have exactly ten or thirteen characters are invalid.
  • Application invalid. An ISBN is considered to be application invalid for a particular record when it appears on the bibliographic item, but it is known, through research or other means, that the same number is also assigned to a different resource. For example, when the ISBNs for different resources are printed in one resource.
020     9780702054389 ‡q (electronic bk.)
020     0702054380 ‡q (electronic bk.)
020     ‡z 9780702053351 ‡q (paperback)
245 0 0 Textbook of adult emergency medicine / ‡c edited by Peter Cameron, ...
264   1 Edinburgh : ‡b Elsevier Ltd., ‡c 2015.
300     1 online resource (xxiii, 1050 pages) : ‡b illustrations (some color)
020     9780702053351‡q (paperback)
020     070205335X ‡q (paperback)
020     ‡z 9780702054389 ‡q (electronic bk.)
245 0 0 Textbook of adult emergency medicine / ‡c edited by Peter Cameron, ...
264   1 Edinburgh : ‡b Churchhill Livingstone/Elsevier, ‡c 2015.
300     xxiii, 1050 pages : ‡b illustrations (some color) ‡c 28 cm.
020     9780764212000 ‡q (cloth ; ‡q alk. paper)
020     0764212001 ‡q (cloth ; ‡q alk. paper)
020     ‡z 9780764212017 ‡q (large print ; ‡q paperback)
100 1   Lewis, Beverly, ‡d 1949-
245 1 4 The last bride / ‡c Beverly Lewis.
264   1 Minneapolis, Minn. : ‡b Bethany House, ‡c 2014.
300     330 pages ; ‡c 23 cm.
020     9780764212017 ‡q (large print ; ‡q paperback)
020     076421201X ‡q (large print ; ‡q paperback)
020     ‡z 9780764212000 ‡q (cloth ; ‡q alk. paper)
100 1   Lewis, Beverly, ‡d 1949-
245 1 4 The last bride / ‡c by Beverly Lewis.
264   1 Waterville, Maine : ‡b Thorndike Press, ‡c 2014.
300     407 pages (large print) ; ‡c 23 cm.


For indexing and searching information, see Searching WorldCat Indexes, field 020.

This page last revised: September 2, 2015