The
International Standard Book Number
(
ISBN) is a uniquenumeric commercial book
identifier based upon the 9digit Standard Book
Numbering (SBN)
code created by Gordon Foster,
now Emeritus Professor of Statistics at Trinity College, Dublin,
for the booksellers and stationers
W.H.
Smith and others in 1966.
The 10digit ISBN format was developed by the
International
Organization for Standardization and was published in 1970 as
international standard ISO 2108.
(However, the 9digit SBN code was used in
the United
Kingdom until 1974.) Currently, the ISO’s TC 46/SC 9 is responsible for the ISBN.
The
ISO online facility only refers back to
1978.
Since 1 January 2007, ISBNs have contained 13 digits, a format that
is compatible with
Bookland EAN13.
Occasionally, a book may appear without a printed ISBN if it is
printed privately or the author does not follow the usual ISBN
procedure; however, this is usually later rectified.
A similar numeric identifier, the
International Standard
Serial Number (ISSN), identifies periodical publications such
as
magazines.
Overview
An ISBN is assigned to each edition and variation (except
reprintings) of a book. The ISBN is 13 digits long if assigned
after January 1, 2007, and 10 digits long if assigned before 2007.
An International Standard Book Number consists of 4 or 5
parts:
The parts of a 10digit ISBN and the
corresponding EAN13 and barcode.
Note the different check digits in each.
The part of the EAN13 labeled "EAN" is the Bookland country
code
 for a 13 digit ISBN, a GS1 prefix:
978 or 979 (indicating the industry; in this case, 978 denotes book
publishing)
 the group identifier, (languagesharing country
group)
 the publisher code,
 the item number, (title of the book) and
 a checksum character or
check digit.
The ISBN parts may be of different lengths, and usually are
separated with
hyphens or spaces.
Group identifier
The group identifier is a 1 to 5 digit number.
The single digit group
identifiers are: 0 or 1 for Englishspeaking countries; 2 for Frenchspeaking countries; 3 for Germanspeaking countries; 4 for Japan; 5
for Russianspeaking countries, 7
for People's
Republic of China, 957+986 for Republic of China and 962+988 for Hong Kong. An example 5 digit group identifier is 99936,
for Bhutan. In
general, the groups are 0–7, 80–94, 950–993, 9940–9989, and
99900–99999. Some catalogs include books that were published with
no ISBN but add a nonstandard number with an asyet unallocated
5digit group such as 99985; this practice is not part of the
standard. Books published in rare languages typically have longer
group identifiers.
The original standard book number (SBN) had no group identifier,
but affixing a zero (0) as prefix to a 9digit SBN creates a valid
10digit ISBN. Group identifiers form a
prefix code; compare with
country calling codes.
Publisher code
The national ISBN agency assigns the publisher number (cf. the
:category:ISBN agencies);
the publisher selects the item number.
Generally, a book
publisher is not required to assign an ISBN, nor is it necessary
for a book to display its number (except in China; see below). However, most book stores only
handle ISBNbearing merchandise.
A listing of all the 628,000 assigned publisher codes is published,
and can be ordered in book form (
€558,
US$915.46). The web site of the ISBN
agency does not offer any free method of looking up publisher
codes. Partial lists have been compiled (from library catalogs) for
the Englishlanguage groups:
identifier 0 and
identifier
1.
Publishers receive blocks of ISBNs, with larger blocks allotted to
publishers expecting to need them; a small publisher may receive
ISBNs of one or more digits for the group identifier code, several
digits for the publisher, and a single digit for the individual
items. Once that block of ISBNs is used, the publisher may receive
another block of ISBNs, with a different publisher number.
Consequently, a publisher may have different allotted publisher
numbers. There also may be more than one group identifier used in a
country. This might occur if a popular identifier has used up all
of its numbers. The cited list of identifiers shows this has
happened in China and in more than a dozen other countries.
By using variable block lengths, a large publisher will have few
digits allocated for the publisher number and many digits allocated
for titles; likewise countries publishing much will have few
allocated digits for the group identifier, and many for the
publishers and titles. Here are some sample ISBN10 codes,
illustrating block length variations.
 { class="wikitable"
Pattern
Englishlanguage publisher codes follow a systematic pattern, which
allows their length to be easily determined, as follows:
Check digits
A
check digitis a form of redundancy
check used for
error detection, the
decimal equivalent of a binary
checksum. It
consists of a single digit computed from the other digits in the
message.
ISBN10
The 2001 edition of the official manual of the
International
ISBN Agencysays that the ISBN10
check
digit— which is the last digit of the tendigit ISBN — must
range from 0 to 10 (the symbol X is used instead of 10) and must be
such that the sum of all the ten digits, each multiplied by the
integer weight, descending from 10 to 1, is a multiple of the
number 11.
Modular arithmeticis
convenient for calculating the check digit using modulus 11. Each
of the first nine digits of the tendigit ISBN — excluding the
check digit, itself — is multiplied by a number in a sequence from
10 to 2, and the remainder of the sum, with respect to 11, is
computed. The resulting remainder, plus the check digit, must equal
11; therefore, the check digit is 11 minus the remainder of the sum
of the products.
For example, the check digit for an ISBN10 of
030640615
?is calculated as follows:\begin{align}
s &= 0*10 + 3*9 + 0*8 + 6*7 + 4*6 + 0*5 + 6*4 + 1*3 + 5*2 \\
&= 0 + 27 + 0 + 42 + 24 + 0 + 24 + 3 + 10 \\
&= 130 \\
\frac{130}{11} &= 11 + \frac{9}{11} \\
11  9 &= 2
\end{align}
Thus, the check digit is 2, and the complete sequence is ISBN
0306406152. Formally, the check digit calculation is: :x_{10}
\equiv 11  (10x_1 + 9x_2 + 8x_3 + 7x_4 + 6x_5 + 5x_6 + 4x_7 + 3x_8
+ 2x_9) \, \bmod\; 11. If the result is 11, a '0' should be
substituted; if 10, an 'X' should be used. The two most common
errors in handling an ISBN (e.g., typing or writing it) are an
altered digit or the transposition of adjacent digits. Since 11 is
a [[prime number]], the ISBN check digit method ensures that these
two errors will always be detected. However, if the error occurs in
the publishing house and goes undetected, the book will be issued
with an invalid ISBN.For example ''I'saka: a sketch grammar of a
language of northcentral New Guinea.'' Pacific Linguistics. ISBN
"0858835544".====Alternative calculation==== The ISBN10
checkdigit can also be calculated in a slightly easier way:
:x_{10} = (1x_1 + 2x_2 + 3x_3 + 4x_4 + 5x_5 + 6x_6 + 7x_7 +8x_8 +
9x_9) \, \bmod\;11. This gives exactly the same result as the
formula above. :x_{10} = \sum_{i=1}^9 ix_i \, \bmod\;11 This finds
the check digit for a 10 digit ISBN, using summation notation.
:x_{10} = 10  \left(\sum_{i=1}^9 (ix_i)  1\right) \, \bmod\;11
This method will output the correct digit, '0', instead of the '11'
outputted by the formal calculation. ===ISBN13=== The 2005 edition
of the International ISBN Agency's official
manual{{PDFlink[http://www.isbninternational.org/en/download/2005%20ISBN%20Users%27%20Manual%20International%20Edition.pdf
ISBN Users' Manual International edition
(2005)]284 KB}}covering some ISBNs issued from January 2007,
describes how the 13digit ISBN [[check digit]] is calculated. The
calculation of an ISBN13 check digit begins with the first 12
digits of the thirteendigit ISBN (thus excluding the check digit
itself). Each digit, from left to right, is alternately multiplied
by 1 or 3, then those products are summed [[modular
arithmeticmodulo]] 10 to give a value ranging from 0 to 9.
Subtracted from 10, that leaves a result from 1 to 10. A zero (0)
replaces a ten (10), so, in all cases, a single check digit
results. For example, the ISBN13 check digit of
978030640615''?'' is calculated as follows: s = 9×1 + 7×3 + 8×1
+ 0×3 + 3×1 + 0×3 + 6×1 + 4×3 + 0×1 + 6×3 + 1×1 + 5×3 = 9 + 21 + 8
+ 0 + 3 + 0 + 6 + 12 + 0 + 18 + 1 + 15 = 93 93 / 10 = 9 remainder 3
10 – 3 = 7 7 / 10 = 0 remainder 7 Thus, the check digit is 7, and
the complete sequence is ISBN 9780306406157.
Formally, the ISBN13 check digit calculation is:
 x_{13} = 10  \big(x_1 + 3x_2 + x_3 + 3x_4 + \cdots + x_{11} +
3x_{12}\big) \,\bmod\, 10.
This check system — similar to the
UPCcheck digit formula — does not
catch all errors of adjacent digit transposition. Specifically, if
the difference between two adjacent digits is 5, the check digit
will not catch their transposition. For instance, the above example
allows this situation with the 6 followed by a 1. The correct order
contributes 3×6+1×1 = 19 to the sum; while, if the digits are
transposed (1 followed by a 6), the contribution of those two
digits will be 3×1+1×6 = 9. However, 19 and 9 are congruent modulo
10, and so produce the same, final result: both ISBNs will have a
check digit of 7. The ISBN10 formula uses the
primemodulus 11 which avoids this blind spot,
but requires more than the digits 09 to express the check
digit.
Additionally, If you triple the sum of the 2nd, 4th, 6th, 8th,
10th, and 12th digits and then add them to the remaining digits
(1st, 3rd, 5th, etc.), the total will always be divisible by 10
(i.e. end in 0).
Errors in usage
Publishers and
librarieshave varied policies
about the use of the ISBN check digit. Publishers sometimes fail to
check the correspondence of a book title and its ISBN before
publishing it; that failure causes book identification problems for
libraries, booksellers, and readers.
Most libraries and booksellers display the book record for an
invalid ISBN issued by the publisher.
The Library of
Congress catalogue contains books published with invalid
ISBNs, which it usually tags with the phrase "Cancelled
ISBN".However, bookordering systems such as
Amazon.comwill not search for a book if an
invalid ISBN is entered to its search engine.
EAN format used in barcodes, and upgrading
Currently, the
barcodeson a book's back
cover (or inside a massmarket paperback book's front cover) are
EAN13; they may have a
separate barcode encoding five digits for the
currencyand the
recommended retail price. The
number "978", the
Bookland"country code", is
prepended to the ISBN in the barcode data, and the check digit is
recalculated according to the EAN13 formula (modulo 10, 1x, and 3x
weighting on alternate digits).
Partly because of a pending shortage in certain ISBN categories,
the
International
Organization for Standardization(ISO) migrated to a
thirteendigit ISBN (ISBN13); the process began January 1, 2005
and was to conclude January 1, 2007. Thirteendigit ISBNs are
prefixed with "978" (and the check digit recalculated); as the
"978" ISBN supply is exhausted, the "979" prefix will be
introduced.
This is expected to occur more rapidly
outside the United
States; originally, "979" was the "Musicland" code for
musical scores with an ISMN, however, ISMN codes will differ visually as they
begin with an "M" letter; the bar code represents the "M" as a zero
(0), and for checksum purposes it will count as a 3.
Publisher identification code numbers are unlikely to be the same
in the "978" and "979" ISBNs, likewise, there is no guarantee that
language area code numbers will be the same. Moreover, the
tendigit ISBN check digit generally is not the same as the
thirteendigit ISBN check digit. Because the EAN/UCC13 is part of
the
Global Trade Item
Number(GTIN) system (that includes the EAN/UCC14, the UPC12,
and the EAN8), it is expected that ISBNgenerating
softwareshould accommodate fourteendigit
ISBNs.
Barcode format compatibility is maintained, because (aside from the
group breaks) the ISBN13 barcode format is identical to the EAN
barcode format of existing ISBN10s. So, migration to an EANbased
system allows booksellers the use of a single numbering system for
both books and nonbook products that is compatible with existing
ISBNbased data, with only minimal changes to
information technologysystems. Hence,
many
booksellers(e.g.
Barnes & Noble) migrated to EAN
barcodes as early as March 2005. Although many American and
Canadian booksellers have been able to read EAN13 barcodes before
2005, most general retailers could not read them. The upgrading of
the
UPCbarcode system to full
EAN13, in 2005, eased migration to the ISBN13 in
North America. Moreover, by January 2007, most
large book publishers added ISBN13 barcodes alongside the
tendigit ISBN barcodes of books published before January
2007.
See also
 ASIN
(Amazon Standard Identification Number)
 CODEN (serial publication identifier
currently used by libraries; replaced by the ISSN for new
works)
 DOI (Digital Object
Identifier)
 ISAN
(International Standard Audiovisual Number)
 ISMN
(International Standard Music Number)
 ISRC
(International Standard Recording Code)
 ISSN
(International Standard Serial Number)
 ISWC
(International Standard Musical Work Code)
 LCCN (Library
of Congress Control Number)
 OCLC (Online
Computer Library Center)
 SICI
(Serial Item and Contribution Identifier)
Footnotes
External links
 National and international agencies
 Online tools
ISBN 
Country or area 
Publisher 

9992158107 
Qatar 
NCCAH, Doha 

9971502100 
Singapore 
World Scientific 

9604250590 
Greece 
Sigma Publications 

8090273416 
Czech Republic; Slovakia 
Taita Publishers 

8535902775 
Brazil 
Companhia das Letras 

1843560283 
United Kingdom 
Simon Wallenberg Press 

0684843285 
Englishspeaking area 
Scribner 

080442957X 
Englishspeaking area 
Frederick Ungar 

0851310419 
Englishspeaking area 
J. A. Allen & Co. 

0943396042 
Englishspeaking area 
Willmann–Bell 

097522980X 
Englishspeaking area 
KT Publishing 

Item number 
0 group identifier 
1 group identifier 
Total 

From 
To 
Number 
From 
To 
Number 

6 digits 
000xxxxxxx 
019xxxxxxx 
20 
100xxxxxxx 
109xxxxxxx 
10 
30 

5 digits 
0200xxxxxx 
0699xxxxxx 
500 
1100xxxxxx 
1399xxxxxx 
300 
800 

4 digits 
07000xxxxx 
08499xxxxx 
1500 
14000xxxxx 
15499xxxxx 
1500 
3000 

3 digits 
085000xxxx 
089999xxxx 
5000 
155000xxxx 
186979xxxx 
31980 
36980 

2 digits 
0900000xxx 
0949999xxx 
50000 
1869800xxx 
1998999xxx 
129200 
179200 

1 digit 
09500000xx 
09999999xx 
500000 
19990000xx 
19999999xx 
10000 
510000 