Posted by Admin Saturday, March 24, 2012 4:54:00 PM

by Brenda L. Speer

ISBN seems like it would be text messaging shorthand for “it’s been” doesn’t it? And it would be used something like this: Isbn gr8 2 c u (for non-texters, that would mean: It’s been great to see you.). Well, ISBN is not text messaging shorthand, but is an acronym with particular meaning in the publishing world.

Part of my clientele is authors and publishers and as a result, I continue to expand my knowledge base about the publishing industry. Here are a few items of interest about books I’ve learned along the way.


Ever wondered what the bar code labeled ISBN on the back of the book is? (Another publishing tidbit: in publishing parlance, the outside back cover of a book is known as Cover 4.) ISBN is an acronym for International Standard Book Number. This number is a unique identifier assigned to every book and it provides a standard way to identify books in global trade. The numbering system was created and implemented in 1966.

“Every book” doesn’t mean per book title, but rather each format and each edition of the same book title. That is, a hard cover book and a paperback book of the same title are two different books and, thus, have two different ISBNs. The same holds true for a first edition and a second edition of the same book.

Through December 31, 2006, books had 10 digit ISBNs. Since January 1, 2007, ISBNs have had 13 digits. So, the digit string in the ISBN provides a clue as to whether the book was published before or after January 2007.

Why did the ISBN change? The change to 13 digits was needed in order to expand the numbering capacity of the ISBN system and alleviate numbering shortages in certain areas of the world. Also, by changing the ISBN to 13 digits, the book industry has fully aligned the numbering system for books with the Global Trade Item Number identification system that is widely used to identify most other consumer goods worldwide.

Part of the number sequence of the ISBN identifies the publisher of the book.  According to the US ISBN agency, R.R. Bowker, that issues ISBNs:

“Once an ISBN publisher prefix and associated block of numbers has been assigned to a publisher by the ISBN Agency, the publisher can assign ISBNs to the publications to which it holds publishing rights. However, after the ISBN Agency assigns ISBNs to a publisher, that publisher cannot resell, reassign, transfer, or split its list of ISBNs among other publishers. These guidelines have long been established to ensure the veracity, accuracy and continued utility of the international ISBN standard.”

The 13 digit identifier breaks down into four or five main parts, usually separated by hyphens in the human readable ISBN digits printed at the top of the bar code:

Part I:   Identifies the country in which the ISBN is assigned

Part II:   Group identifier (language-sharing country group)

Part II:   Identifies the publisher to whom the ISBN was originally allocated

Part III:  Identifies the title

Part IV: Check digit which ensures each ISBN is valid (last digit)

With the exception of the final check digit, each part of the ISBN varies in the number of digits depending on the applicable number string designated to identify a particular country, group, publisher and title.


The acronym LCCN stands for Library of Congress Control Number. LCCNs are issued by the US Library of Congress upon application of the publisher. The number usually appears on the preliminary page which contains copyright information.

The LCCN numbering system has been in use since 1898. Originally, LCCN stood for Library of Congress Card Number, because the Library of Congress prepared cards of bibliographic information about each book for its library catalog (remember card catalogs?) and it sold duplicate sets of the cards to other libraries for use in their catalogs. This system is known as centralized cataloging. Each set of cards was given a serial number to identify it.

The LCCN is a serially based system of numbering cataloging records in the Library of Congress. Unlike the Dewey Decimal Classification or the Library of Congress Classification, the LCCN has nothing to do with the contents of the book. Rather the number identifies the catalog card that provides identifying bibliographic information about the corresponding book.

Although the bibliographic information now is electronically created, stored and shared with other libraries, the need still exists to identify each unique record. The LCCN continues to perform this function.

Libraries worldwide use the LCCN to catalog most books which have been published in the US. Beginning in February 2008, the Library of Congress created the LCCN Permalink Services which provides a stable URL (Uniform Resource Locator, or identifier of a particular web page on the Internet) for all LCCNs.

The basic parts of the LCCN include a year (year the card was created) and a serial number (to identify the particular card set). For the years 1898-2000, a two-digit year identifier was used and since 2001 a four-digit year identifier has been used. Serial numbers are six digits, including any leading zeros.


The printers key, also known as the number line, is a convention publishers started using in 1945 to indicate the print run of a book. A print run means all copies of a book printed at a particular time. For example, a first print run of a book may be 5,000 copies. Once the first print run is sold out and more copies of the book need to be printed, that would be the second print run and so on.

The printers key appears on the preliminary or copyright page. A printers key number or letter string looks something like one of these examples:

1 2 3 4 5 6 7 8 9

9 8 7 6 5 4 3 2 1

a b c d e f g h i j k

2 4 6 8 10 9 7 5 3 1

1 3 5 7 9 10 8 6 4 2

The purpose of alternating the digits from left to right, as in the last two examples, is so that the line of numbers remains roughly centered on the page even as the numbers are removed with subsequent printings.

The lowest alpha-numeric character that appears in the printers key indicates the particular print run. That is, if “1” or “a” is present, then that book was produced in the first print run. If there is no “1” or “a,” then that book was produced in a second print run; if there is no “2” or “b,” then that book was produced in a third print run; etc.

Some printers keys also include a date line to indicate the year in which the print run occurred. A printers key for a book that had a third print run in 1980 might look like this:

3 4 5 6     83 82 81 80

Why are the numbers removed, instead of added, with each successive printing? This convention is a hold-over from the days of the hot-metal press where each character on a page was a metal block.

Once a page was set up, the printer needed to remove only a character block from that page’s print sheet before reprinting. Removing only an outer character block, versus adding a block, meant that the fewest possible changes had to be made to the page of characters. In turn, these minimal changes reduced the likelihood of a printing mistake and the resultant charge to the publisher for the change necessitated by the new print run.

The next time you pick up a book, pause a moment to take a look at the preliminary or copyright page. You’ll now be able to decipher some of the information contained on it.

Happy reading!

© 2009 BL Speer & Associates

BL Speer & Associates
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