Internet DRAFT - draft-ietf-urnbis-rfc3187bis-isbn-urn
draft-ietf-urnbis-rfc3187bis-isbn-urn
IETF URNbis WG M. Huttunen
Internet-Draft J. Hakala
Obsoletes: 2288,3187 (if approved) The National Library of Finland
Intended status: Standards Track A. Hoenes, Ed.
Expires: April 22, 2013 TR-Sys
October 19, 2012
Using International Standard Book Numbers as Uniform Resource Names
draft-ietf-urnbis-rfc3187bis-isbn-urn-03
Abstract
The International Standard Book Number, ISBN, is a widely used
identifier for monographic publications. Since 2001, the URN
(Uniform Resource Name) namespace "ISBN" has been reserved for ISBNs.
The namespace registration was performed in RFC 3187 and applied only
to the ISBN as specified in the ISO Standard 2108-1992, now known as
"ISBN-10". To allow for further growth in use, the successor ISO
Standard, ISO 2108:2005, has defined an expanded format for the ISBN,
known as "ISBN-13". This document defines how both of these ISBN
standard versions can be supported within the URN framework.
Moreover, additional query and fragment usage related information
required by RFC 2141bis has been included. An updated namespace
registration conformant to RFC 3406bis is provided. It describes how
both the old and the new ISBN format can share the same namespace.
This document replaces RFC 3187; it also obsoletes and moves to
Historic status the predecessor thereof, RFC 2288.
Discussion
This draft is based on individual work started in 2008. When the
URNBIS working group was launched, revision of the ISBN namespace
registration was included in its charter.
Comments are welcome and should be directed to the urn@ietf.org
mailing list or the authors.
[[ RFC-Editor: this clause to be deleted before RFC publication ]]
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Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 22, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Without obtaining an adequate license from the person(s) controlling
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it for publication as an RFC or to translate it into languages other
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 5
3. Fundamental Namespace and Community Considerations . . . . . . 5
3.1. The URN:ISBN Namespace . . . . . . . . . . . . . . . . . . 5
3.2. Community Considerations for ISBNs . . . . . . . . . . . . 5
4. International Standard Book Numbers . . . . . . . . . . . . . 6
4.1. Overview / Namespace Considerations . . . . . . . . . . . 6
4.1.1. ISBN-10 Structure . . . . . . . . . . . . . . . . . . 6
4.1.2. ISBN-13 Structure . . . . . . . . . . . . . . . . . . 7
4.1.3. Relation between ISBN-10 and ISBN-13 . . . . . . . . . 7
4.2. Encoding Considerations . . . . . . . . . . . . . . . . . 8
4.3. Resolution of ISBN-based URNs . . . . . . . . . . . . . . 8
4.3.1. General . . . . . . . . . . . . . . . . . . . . . . . 8
4.3.2. Practical Aspects . . . . . . . . . . . . . . . . . . 9
4.4. Additional Considerations . . . . . . . . . . . . . . . . 12
5. URN Namespace Registration and Use . . . . . . . . . . . . . . 13
5.1. URN Namespace ID Registration for the International
Standard Book Number (ISBN) . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.1. Normative References . . . . . . . . . . . . . . . . . . . 19
9.2. Informative References . . . . . . . . . . . . . . . . . . 20
Appendix A. Draft Change Log . . . . . . . . . . . . . . . . . . 21
A.1. draft-hakala-rfc3187bis-isbn-urn-00 to
draft-ietf-urnbis-*-00 . . . . . . . . . . . . . . . . . . 21
A.2. draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01 . . . . . 21
A.3. draft-ietf-urnbis-rfc3187bis-isbn-urn-01 to -02 . . . . . 21
A.4. draft-ietf-urnbis-rfc3187bis-isbn-urn-02 to -03 . . . . . 21
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1. Introduction
One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986],
[IANA-URI]) is 'URN' (Uniform Resource Name) as originally defined in
RFC 2141 [RFC2141] and now being formally specified in RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn]. Any identifier, when used within
the URN system, needs its own namespace. At the time of this
writing, there were over 45 registered URN namespaces (see
[IANA-URN]), one of which belongs to ISBN, International Standard
Book Number, as specified 2001 in RFC 3187 [RFC3187].
Since 2007, there have been two variants of ISBN in use; an outdated
one based on ISO 2108-1992 [ISO1] and a new one defined in ISO 2108-
2005 [ISO2]. These versions shall subsequently be called "ISBN-10"
and "ISBN-13", respectively. If what is said in this document
applies to both ISBN versions, the generic term "ISBN" is used.
As part of the validation process for the development of URNs, the
IETF URN working group agreed that it is important to demonstrate
that a URN syntax proposal can accommodate existing identifiers from
well established namespaces. One such infrastructure for assigning
and managing names comes from the bibliographic community.
Bibliographic identifiers function as names for objects that exist
both in print and, increasingly, in electronic formats. RFC 2288
[RFC2288] investigated the feasibility of using three identifiers
(ISBN, ISSN, and SICI -- see below) as URNs, with positive results;
however, it did not formally register corresponding URN namespaces.
This was in part due to the still evolving process to formalize
criteria for namespace definition documents and registration,
consolidated later in the IETF, first into RFC 2611 [RFC2611], then
into RFC 3406 [RFC3406], and now given by RFC 3406bis
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
URN Namespaces have subsequently been registered for both ISBN
(International Standard Book Number) and ISSN (International Serial
Standard Number) in RFCs 3187 [RFC3187] and 3044 [RFC3044],
respectively, but not for SICI (Serial Item and Contribution
Identifier), mainly due to the identifier's limited popularity.
Guidelines for using ISBN-10s (based on ISO 2108:1992) as URNs and
the original namespace registration have been published in RFC 3187
[RFC3187]. The RFC at hand replaces RFC 3187; sections related to
ISBN-13 have been added, all ISBN-10 information has been updated,
and the namespace registration revised to make it compliant with both
ISBN versions and the stipulations of RFC 3406bis
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
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2. Conventions used in this document
When spelled in all-capitals as in this paragraph, the key words
"MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document
are to be interpreted as described in BCP 14 [RFC2119].
"ISBN-10" refers to the original, 10-digit ISBN scheme specified in
ISO 2108-1992 [ISO1].
"ISBN-13" refers to the current, 13-digit ISBN scheme specified in
ISO 2108-2005 [ISO2].
"URN:ISBN" is used as a shorthand for "ISBN-based URN".
3. Fundamental Namespace and Community Considerations
3.1. The URN:ISBN Namespace
ISBN is a well established standard identifier system for monographic
publications. Therefore, any useful and deployable method for
identifying these entities for Internet-wide reference and making
their metadata available on the Internet needs to be based on ISBNs.
3.2. Community Considerations for ISBNs
ISBNs are assigned under the auspices of the International ISBN
Agency [ISBNORG] and national/regional ISBN agencies. ISBN
assignment is a well managed and understood process, but as in any
process administered by humans, errors do take place. If so, there
are procedures in place for fixing the incorrect ISBNs.
Books are finite objects, which may consist of (logical) component
resources such as chapters or short stories / novellas. Such
component resources can get an ISBN if and only if they are for sale
independently. For example, a user could purchase either the entire
short story collection, or just one short story. Either way, he gets
a file with the relevant content. Logical components can also be
represented in the physical structure of the document; for instance,
chapters of a digital book may be encoded into its HTML structure.
Then and only then an URI fragment can be attached to the URN:ISBN.
The entire resource will be retrieved, but the fragment will be
applied by the browser to take the user into the desired point within
the document. Please note that according to the ISBN standard, ISBN
MUST be assigned to a single manifestation of the resource. An ISBN
given to the PDF version of the book cannot be reused to the EPUB 3
version.
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The ISBN standard does not allow augmentation of the ISBN itself with
an identification of a physical component resource of a book.
However, if a fragment part is added to a URI reference to an URN:
ISBN, the namespace specific string is still the base ISBN only, and
lexically, the URN with and without the URI fragment identifier are
equivalent.
For the ISBN community, the use of URI fragment identifiers provides
additional functionality that would not be easily available in any
other way. An ISBN-13 can be assigned to logical component
resources, but this feature has not been used extensively. URI
fragment offers a light-weight (technically and administratively)
solution to the users to pinpoint component resources within
electronic manifestations of books, provided that these components
have been encoded in an appropriate manner.
The materials identified by an ISBN can exist only in printed or
other physical form, not as digital resources accessible in the WEB;
and even if an electronic book exists, its access rights may be
limited. ISBN-based URN resolution services are expected to support
a wide variety of information services related to books. Hence, when
the identified manifestation of the book cannot be supplied, the
applicable URN:ISBN resolver SHOULD supply descriptive and rights
metadata about the relevant manifestation; the resolver MAY also
provide links to other manifestations of the same work, or to related
works.
The next section presents an overview of the application of the URN:
ISBN namespace and the principles, and systems used, for the
resolution of ISBN-based URNs.
4. International Standard Book Numbers
4.1. Overview / Namespace Considerations
An International Standard Book Number (ISBN) identifies a product
form or edition of a monographic publication. ISO 2108 requires that
each product form (e.g. hardcover, paperback, PDF) has its own ISBN.
4.1.1. ISBN-10 Structure
The ISBN-10 is defined by the ISO Standard 2108-1992 [ISO1]. It is a
ten-digit number (the last "digit" can be the letter "X" as well)
that is divided into four variable-length parts usually separated by
hyphens when printed. Note that these hyphens can be removed; ISBNs
with and without the hyphens are lexically equivalent. The parts are
as follows (in this order):
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o a group identifier that specifies a group of publishers, based on
national scope, geographic scope, or some other criteria;
o the publisher identifier;
o the title identifier; and
o a modulo 11 check digit, using X instead of 10; the details of the
calculation are specified in the ISO Standard [ISO1].
ISBN-10s were assigned starting from the 1970s until the introduction
of ISBN-13 in January 2007.
4.1.2. ISBN-13 Structure
ISBN-13 is defined by the ISO Standard 2108-2005 [ISO2]. The ISBN-13
is a thirteen-digit number that is divided into five parts usually
separated by hyphens when printed. The first and the last part have
a fixed lenght, but the other parts have variable length. These
parts are as follows (in this order):
o an ISBN-13 prefix element -- a 3-digit prefix specified by the
International ISBN Agency; at the time of this writing, applicable
values were 978 and 979; future versions of the standard may
define additional values;
o a registration group element that specifies the registration
group; it identifies the national, geographic, language, or other
such grouping within which one or more ISBN Agencies operate;
o the registrant element;
o the publication element; and
o a modulo 10 check digit; the details of the calculation are
specified in the ISO Standard [ISO2].
4.1.3. Relation between ISBN-10 and ISBN-13
The structural differences between the ISBN-10 and ISBN-13 are the
prefix element (which does not exist in the ISBN-10) and the check
digit calculation algorithm, which is modulo 11 in ISBN-10 and modulo
10 in ISBN-13.
Further, the terminology in ISBN-10 differs substantially from the
terminology applied in ISBN-13. In this document, ISBN-13
terminology shall be used from now on; for a reader used to ISBN-10
terminology, the following mapping may be useful:
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o ISBN-10 group identifier <-> ISBN-13 registration group element
under prefix 978;
o ISBN-10 publisher identifier <-> ISBN-13 registrant element;
o ISBN-10 title identifier <-> ISBN-13 publication element.
Any ISBN-10 can be converted to ISBN-13 form (and retrospective
conversion is the recommended practice in ISO 2108:2005) by mapping
it into the ISBN-13 prefix-978 range and recalculating the check
digit. Any application that processes ISBN-based URNs MUST be
prepared to deal with both kinds of ISBNs, since instances of ISBN-10
numbers will persist that cannot be converted to the new form (e.g.,
ISBNs imprinted in books). ISBN-13s using prefix element 979 cannot
be converted back to ISBN-10, since under this prefix, ISBNs group
identifiers will be re-assigned from scratch. New books may still
have ISBN-10 alongside ISBN-13 for practical reasons, but only as
long as the prefix element in ISBN-13 is 978.
4.2. Encoding Considerations
Embedding ISBNs within the URN framework does not present encoding
problems, since all of the characters that can appear in an ISBN are
valid in the namespace-specific string (NSS) part of the URN.
Percent-encoding, as described in RFC 2141bis
[I-D.ietf-urnbis-rfc2141bis-urn], is never needed. In order to
improve readability of the NSS, hyphens MAY be used.
Example 1: URN:ISBN:978-0-395-36341-6
Example 2: URN:ISBN:951-0-18435-7
Example 3: URN:ISBN:951-20-6541-X
Example 3: URN:ISBN:951206541X
4.3. Resolution of ISBN-based URNs
4.3.1. General
For URN resolution purposes, all elements except the check digit (0-9
for ISBN-13, and 0-9 or X for legacy ISBN-10) must be taken into
account. The registration group and registrant element assignments
are managed in such a way that the hyphens are not needed to parse
the ISBN unambiguously into its constituent parts. However, the ISBN
is normally transmitted and displayed with hyphens to make it easy
for humans to recognize these elements without having to make
reference to or have knowledge of the number assignments for
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registration group and registrant elements. In ISBN-10, registration
group element codes such as 91 for Sweden were unique. In ISBN-13,
only the combinations of prefix and registration group elements are
guaranteed to be unique. 978-951 and 978-952 both mean Finland, but
979-951 and 979-952 almost certainly will not (once they will be
assigned in the future); at the time of this writing, registration
group element(s) for Finland are not yet known for ISBNs starting
with 979.
The Finnish URN registry is maintained by the national library. The
service is capable of resolving ISBN-based URNs. URNs starting with
URN:ISBN:978-951 or URN:ISBN:978-952 are mapped into appropriate URL
addresses in a table maintained within the registry. Applications,
such as the national bibliography or the open archive of a
university, can use the URN as the persistent address of the
resource. There is just one place (the URN registry) where the
address is mapped to one or more physical locations.
ISBN-13 prefix / registration group element combinations (and the
corresponding ISBN-10 registration group identifiers, if any) usually
designate a country, but occasionally a single combination / ISBN-10
group identifier is used to indicate a language area. For instance,
"978-3" (or "3" in ISBN-10) is utilised in Germany, Austria, and the
German speaking parts of Switzerland. As of this writing, there are
two regional registration groups: "978-976" is used in the Caribbean
community and "978-982" in the South Pacific (see [ISBN_PREFIX]).
Note that the prefix and registration group element combination
"979-3" has not yet been assigned. There is no intention to allocate
the registration group elements in the same way as was done with
ISBN-10.
The registrant element may or may not be used for resolution
purposes, depending on whether individual publishers have set up
their resolution services.
The publication element shall enable targeting the individual
publication.
4.3.2. Practical Aspects
Due to the lack of URN support in, e.g., web browsers, the URNs are
usually expressed as URLs when embedded in documents. The Finnish
URN registry is located at <http://urn.fi/>, and URNs are therefore
expressed in the form http://urn.fi/<URN>. For example, the URI
<http://urn.fi/URN:ISBN:978-952-10-3937-9> identifies Sami Nurmi's
doctoral dissertation "Aspects of Inflationary Models at Low Energy
Scales".
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Any national URN registry can resolve URN:ISBNs with foreign
registration group element values if a) there is a URN:ISBN
resolution service for that country, b) the national resolution
service is aware of the existence of the foreign service and how to
find it, and c) the two resolution services can communicate with one
another. The PERSID project (<http://www.persid.org/>) developed
such an infrastructure for the URN:NBN namespace.
Alternatively, instead of linking the national resolvers together, it
is also possible to build international resolvers that copy
resolution data from several national services, or to create a way
station which will enable the resolvers to communicate with one
another. We can assume that the network of URN:ISBN resolvers will
grow, and at the same time the set of services they support will also
grow and become more diverse. Such development might make these
union resolvers and way stations more important.
If a registration group element does not identify a single country
but a language area, there are at least two means for locating the
correct national bibliography. First, it is possible to define a
cascade of URN registries -- for instance, the German, Austrian, and
Swiss national registries, in this order --, which collectively is
aware of resolution services such as national bibliographies for
ISBN-13s starting with "978-3". If the German registry is not able
to find an authoritative resolution service, the request could be
passed on to the Austrian one, and if there are still no hits,
finally to the Swiss service.
Second, the registrant element ranges assigned to the publishers in
Germany, Austria, and Switzerland by the respective ISBN Agencies
could be defined directly into the national registries. This method
would be more efficient than cascading, since the correct resolution
service would be known immediately. The choice between these two and
possible other options should be made when the establishment of the
European network of URN registries reaches this level of maturity.
In some exceptional cases -- notably in the US and in the UK, where
international companies do a significant portion of publishing -- the
information provided by the group identifier may not always be fully
reliable. For instance, some monographs published in New York by
international publishing companies may get an ISBN with the
registration group element "3". This is technically appropriate when
the headquarters or one of the offices of the publisher is located in
Germany.
Information about such a book may not always be available in the
German national bibliography, but via the Library of Congress
systems. Unfortunately, the German/Austrian/Swiss URN registries
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that should in this case be contacted may not be aware of the
appropriate resolution service.
However, the problem posed by the international publishers may be
less severe than it looks. Some international publishers (Springer,
for example) give the whole production to the national library of
their home country as legal deposit, no matter which country the book
was published. Thus everything published by Springer in New York
with registration group element "3" should be resolvable via the
German national bibliography. On the other hand, when these
companies give their home base also as a place of publication, the
"home" national library requires the legal deposit.
A large union catalogue, such as WorldCat maintained by OCLC
[OCLC-WC] can be used to complement the resolution services provided
in the national level, or as the default service, if no national
services exist or are known to the registry from which the query
originates.
Due to the semantic structure of ISBN-13, the registrant element can
be used as a "hint". Technically, it is possible to establish a
number of URN resolution services maintained by different kinds of
organizations. For instance, "978-951-0" is the unique ISBN
registrant element of the largest publisher in Finland, Sanoma-WSOY.
Resolution requests for ISBNs starting with "978-951-0" can be passed
to and dealt with the publisher's server, if and when it is made URN-
aware. In such a case, resolving the same URN in multiple locations
MAY provide different services; the national bibliography might be
able to provide bibliographic information only, while the publisher
can provide the book itself, on its own terms. Users can expect
Resolution services to co-exist and complement one another. The same
ISBN can be resolved both as URN and as a Digital Object Identifier
(DOI) [DOIHOME]. URN-based services hosted by, e.g., a national
library, might provide only bibliographic metadata, whereas a service
based on the DOI system provided by the publisher may supply the
book, parts of the book or various other services.
Persistence is one of the key features for any persistent identifier
system. There are three inter-related aspects of persistence that
need to be discussed: persistence of the resource itself, persistence
of the identifier, and persistence of the URN-based resolvers.
ISBNs are assigned to manifestations (physical embodiments) of books.
Thus each digital version of a book (PDF, XML and so on) MUST receive
its own ISBN. This quarantees that if URI fragment is added to the
NSS, it remains functional as long as the digital manifestation is
available.
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Printed books and library catalogues are persistent, so even after
500 years, a URN:ISBN identifying a printed book can resolve to a
bibliographic description of the book, which usually tells where the
book can be found in, e.g., libraries' collections.
With digital books things get more complicated. According to ISO
2108, each product form must have a separate ISBN. Since digital
manifestations are not long-lived, future users who try to find and
old version of an electronic book, are not likely to find that
version. Instead there will be several modernized versions of the
resource, produced via migration. There might also be a printed book
with similar intellectual content. These manifestations of a book
SHOULD be interlinked (using, for instance, the work level metadata
record with URN:ISBN links to all manifestations) so as to make a
user aware of the existence of alternative sources. Such
interlinking enables the users to retrieve manifestations which match
their interests best. Different users are likely to have different
preferences. While some users prefer a modern manifestation which no
longer has the authentic look and feel, there are users who want the
"first edition" even if it requires digital archaeology for access.
Persistence of URN:ISBN resolvers themselves is mainly an
organizational issue, related to the persistence of organizations
maintaining them. URN:ISBN resolution services are currently
supplied by several national libraries to enable access to their
legal deposit collections. These URN:ISBN resolution services are
likely to be relatively persistent.
4.4. Additional Considerations
The basic guidelines for assigning ISBNs to electronic resources are
the following:
o Product form and the means of delivery are irrelevant to the
decision whether a product needs an ISBN or not. If the content
meets the requirements of the standard, it gets an ISBN, no matter
what the file format or the delivery system.
o Each product form (manifestation) of a digital publication should
have a separate ISBN. The definition of a new edition is normally
based on one of the two criteria:
* A change in the kind of packaging involved: the hard cover
edition, the paperback edition and the library-binding edition
would each get a separate ISBN. The same applies to different
versions of digital books.
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* A change in the text, excluding packaging or minor changes such
as correcting a spelling error. Again, this criterion applies
regardless of whether the publication is in printed or in
digital form.
Although these rules seem clear, their interpretation may vary. As
already RFC 2288 [RFC2288] pointed out,
The choice of whether to assign a new ISBN or to reuse an existing
one when publishing a revised printing of an existing edition of a
work or even a revised edition of a work is somewhat subjective.
Practice varies from publisher to publisher (indeed, the
distinction between a revised printing and a new edition is itself
somewhat subjective). The use of ISBNs within the URN framework
simply reflects these existing practices.
Since ISBN assignment is a manual process mistakes do happen. For
instance, ISBNs are occasionally re-used for another book or another
manifestation of the same book. Such human errors are relatively
rare and do not threaten or undermine the value of the ISBN system as
a whole. They are not a serious risk to the URN resolution service
based on ISBNs.
Libraries routinely correct ISBN mistakes. Their catalogs provide
cross references ("incorrect ISBN -> correct ISBN"). This MUST be
taken into account in the URN resolution process. Further details on
the process of assigning ISBNs can be found in Section 5 (Namespace
registration) below.
5. URN Namespace Registration and Use
The formal URN Namespace Identifier Registration for the pre-2005
version of the International Standard Book Number (ISBN) was done in
RFC 3187 [RFC3187].
The new ISBN standard does not require a new namespace, but the
registration is renewed here. The registrant organization has moved
from Staatsbibliothek zu Berlin - Preussischer Kulturbesitz to The
International ISBN Agency, London, U.K. Moreover, the description of
the NSS and resolution details have been amended.
5.1. URN Namespace ID Registration for the International Standard Book
Number (ISBN)
This registration describes how International Standard Book Numbers
(ISBN) can be supported within the URN framework.
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[ RFC Editor: please replace "XXXX" in all instances of "RFC XXXX"
below by the RFC number assigned to this document. ]
Namespace ID: ISBN
This Namespace ID has already been assigned to the International
Standard Book Number in January 2001 when the namespace was
initially registered.
Kind of named resources:
Manifestations of monographic publications.
Registration Information:
Version: 2
Date: 2012-10-19
Declared registrant of the namespace:
Registering Organization: The International ISBN Agency
Designated Contact Person:
Name: Ms. Stella Griffiths
Affiliation: Executive Director, The International ISBN Agency
Email: info@isbn-international.org
Postal: EDItEUR, 39-41 North Road, London, N7 9DP, U.K.
Web URL: <http://www.isbn-international.org/>
Declaration of syntactic structure of NSS part:
The namspace-specific string of 'ISBN' URNs is either an ISBN-13
(see Section 4.1.2 of RFC XXXX) or an ISBN-10 (see Section 4.1.1
of RFC XXXX); the former is preferred.
Example 1: URN:ISBN:978-0-395-36341-6
Example 2: URN:ISBN:951-0-18435-7
Example 3: URN:ISBN:951-20-6541-X
Example 4: URN:ISBN:951206541X
Relevant ancillary documentation:
The ISBN (International Standard Book Number) is a unique machine-
readable identification number, which marks any edition of a book
unambiguously. This number is defined in ISO Standard 2108:2005.
ISBNs has been in use for more than 30 years and they have
revolutionised the international book-trade. 170 countries and
territories are officially ISBN members.
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The administration of the ISBN system is carried out on three
levels:
International agency,
Group agencies,
Publishers.
The International ISBN agency is located in London. The main
functions of the Agency are:
* To promote, co-ordinate and supervise the world-wide use of the
ISBN system.
* To approve the definition and structure of group agencies.
* To allocate group identifiers to group agencies.
* To advise on the establishment and functioning of group
agencies.
* To advise group agencies on the allocation of international
publisher identifiers.
* To publish the assigned group numbers and publisher prefixes in
up-to-date form.
Detailed information about ISBN usage can be found from the ISBN
Users' Manual [ISBN_UM]. A shorter introduction to ISBN usage can
be found from the ISBN FAQ web pages [ISBN_FAQs], which also
include guidelines for the assignment of ISBNs to e-books.
Conformance with URN Syntax:
Legal ISBN characters are 0-9 and hyphen for ISBN-13 and 0-9,
hyphen, and X for ISBN-10. No percent-encoding is needed. Hyphen
carries no semantic content and MAY be dropped from the NSS.
Rules for Lexical Equivalence of NSS part:
ISBN numbers are usually printed with the letters 'ISBN' and a
single blank preceding the ISBN proper (for instance: ISBN 951-
746-795-8). The data preceding the ISBN MUST NOT be included in
the NSS. No percent-encoding is needed.
Prior to comparing the NSS of two ISBN-based URNs for equivalence,
all hyphens, if present, MUST be removed and letter 'X'
capitalized. Prior to comparing a URN based on ISBN-10 with a URN
based on ISBN-13, the ISBN-10 MUST be converted to the ISBN-13
form. This step is necessary since it is not possible to know if
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the ISBN-10s have been converted to the new form; libraries SHOULD
keep the old ISBN since it is the one printed in books published
prior to 2007, while publishers MAY convert the old identifiers
originally assigned in ISBN-10 form and use the equivalent ISBN-
13s in unchanged reprints of the books, which according to the
ISBN assignment rules should not receive a new ISBN.
Note that the prefix "URN:ISBN:" is case-insensitive; generic URI
parsing and comparison software frequently uses lower case as the
canonical (normalized) form.
Note that URI fragment and/or query, if present, are not part of
the NSS and MUST be removed before the lexical equivalence is
determined. Thus urn:isbn:978-951-1-25645-8,
urn:isbn:978-951-1-25645-8?s=U2C and
urn:isbn:978-951-1-25645-8#chapter2 are lexically equivalent,
although the URN resolvers will treat them in a different manner.
The URNs are equivalent if the normalized forms compare equal.
Usage of query instructions:
URN:ISBN resolvers MAY support several global services. Some of
them have been specified in RFC 2483; some remain unspecified.
Examples of existing relevant services are URI to URL or URLs, URI
to URN or URNs, URI to resource or resources, and URI to URC or
URCs. The component directive is relevant especially to the URI
to URC service, where it can be used to, e.g., indicate the
preferred metadata format or the completeness of the metadata
record or the metadata content requested such as table of
contents. A URN resolver maintained by a national library may
consult for instance the national bibliography, digital asset
management systems and digital preservation systems to supply
these services.
Examples of services which may be specified and implemented in the
future: request the oldest and most original manifestation of the
resource; request the latest version of the resource and request
metadata related to the work.
Usage of fragment part:
If URI-to-resource service is used and the media type supports the
use of URI fragment parts, the users can ustilize that to indicate
locations within the identified resources since ISBNs are assigned
to one and one only manifestation of a resource.
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The URN:ISBN Namespace does not impose any restrictions of its own
on the fragment identifiers allowed, beyond what the respective
media type admits.
Identifier uniqueness considerations:
ISBN is a unique identifier. An ISBN, once it has been assigned,
MUST NOT be re-used for another book or another product form
(manifestation) of the same book.
URN:ISBNs inherit the uniqueness properties from ISBNs. Please
note that the same ISBN can be used in another persistent
identifier system, such as DOI or Handle. The resulting
persistent identifier is likely to provide different resolution
services than URN:ISBN.
If there are multiple manifestations of a single literary work
such as a novel, each one MUST receive a different ISBN. ISTC
(International Standard Text Code, ISO 21047-2009) enables
identification of textual works. See
<http://www.istc-international.org/> for more information. Annex
E of the ISTC standard describes the relations between ISTC and
publication identifiers such as ISBN.
Identifier persistence considerations:
ISBN is a persistent identifier. Once a book has received an
ISBN, it MUST NOT get a new ISBN.
URN:ISBNs inherit the persistence properties from ISBNs.
Since ISBNs are attached to manifestations, a URI fragment, if
attached to the URN:ISBN, is as persistent as the ISBN itself.
Support for URI query is likely to be less persistent, since it is
dependent on applications supporting the functionality requested.
Process of identifier assignment:
Assignment of ISBNs is controlled, and URN:ISBNs inherit this
property. There are three levels of control: the international
agency, group agencies that typically operate in the national
level, and finally each publisher is responsible of using the ISBN
system correctly. Small publishers may demand ISBN numbers one at
a time by contacting the ISBN group agency. Large publishers
receive ISBN blocks from which they allocate ISBNs to the books
according to the ISBN assignment rules.
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Process for identifier resolution:
See Section 4.3 of RFC XXXX.
Validation mechanism:
The check digit helps to assure the correctness of an ISBN number
assigned for a book when it has been entered or processed.
Applications processing bibliographic data such as integrated
library systems MAY check the correctness of both ISBN-10 and
ISBN-13 (and make conversions between the two). If the number is
wrong due to, e.g., a typing error made by a publisher, a correct
ISBN SHOULD be assigned afterwards. Although the book will only
contain the wrong number, national bibliography and system used by
the book trade often will contain both the wrong and new, correct
ISBN number.
Scope:
ISBN is a global identifier system used for identification of
monographic publications. It is very widely used and supported by
the publishing industry.
6. Security Considerations
This document proposes means of encoding ISBNs within the URN
framework. An ISBN-based URN resolution service is depicted here
both for ISBN-10 and ISBN-13, but only in a fairly generic level;
thus questions of secure or authenticated resolution mechanisms are
excluded. It does not deal with means of validating the integrity or
authenticating the source or provenance of URNs that contain ISBNs.
Issues regarding intellectual property rights associated with objects
identified by the ISBNs are also beyond the scope of this document,
as are questions about rights to the databases that might be used to
construct resolvers.
Beyond the generic security considerations laid out in the underlying
documents listed in the Normative References (Section 9.1), no
specific security threats have been identified for ISBN-based URNs.
7. IANA Considerations
IANA is asked to update the existing registration of the Formal URN
Namespace 'ISBN' using the template given above in Section 5.1, which
follows the outline specified in RFC 3406bis
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
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8. Acknowledgements
This draft version is the outcome of work started in 2008 and brought
to the IETF in 2010 to launch a much larger effort to revise the
basic URN RFCs. The aim in the IETF is to bring these RFCs in
alignment with the current URI Standard (STD 63, RFC 3986), ABNF, and
IANA guidelines. The participants of project PERSID
(<http://www.persid.org/>) contributed significantly to the standards
work.
Leslie Daigle has provided valuable guidance in the initial draft
stage of this memo.
Stella Griffiths has advised and guided the development of this
document, has verified the technical content from the director's view
of the International ISBN Agency, and provided valuable comments.
Larry Masinter, Subramanian Moonesamy, Julian Reschke, and other
participants of the URNbis working group have provided review
comments and text suggestions that have improved this document.
9. References
9.1. Normative References
[I-D.ietf-urnbis-rfc2141bis-urn]
Hoenes, A., "Uniform Resource Name (URN) Syntax",
draft-ietf-urnbis-rfc2141bis-urn-03 (work in progress),
October 2012.
[I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]
Hoenes, A., "Defining Uniform Resource Name (URN)
Namespaces", draft-ietf-urnbis-rfc3406bis-urn-ns-reg-03
(work in progress), October 2012.
[ISO1] ISO, "Information and documentation - The International
Standard Book Number (ISBN)", ISO 2108-1992, 1992.
[ISO2] ISO, "Information and documentation - The International
Standard Book Number (ISBN)", ISO 2108-2005, 2005.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
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9.2. Informative References
[DOIHOME] International DOI Foundation, "The Digital Object
Identifier System", <http://www.doi.org/>.
[IANA-URI]
IANA, "URI Schemes Registry",
<http://www.iana.org/assignments/uri-schemes/>.
[IANA-URN]
IANA, "URN Namespace Registry",
<http://www.iana.org/assignments/urn-namespaces/>.
[ISBNORG] International ISBN Agency, "",
<http://www.isbn-international.org/>.
[ISBN_FAQs]
International ISBN Agency, "ISBN Prefix Ranges",
<http://www.isbn-international.org/faqs>.
[ISBN_PREFIX]
International ISBN Agency, "ISBN Prefix Ranges",
<http://www.isbn-international.org/page/ranges>.
[ISBN_UM] International ISBN Agency, "ISBN Users' Manual",
<http://www.isbn-international.org/page/info>.
[OCLC-WC] OCLC WorldCat, "WorldCat.org: The World's Largest Library
Catalog", <http://www.worldcat.org>.
[RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
[RFC2288] Lynch, C., Preston, C., and R. Jr, "Using Existing
Bibliographic Identifiers as Uniform Resource Names",
RFC 2288, February 1998.
[RFC2611] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
"URN Namespace Definition Mechanisms", BCP 33, RFC 2611,
June 1999.
[RFC3044] Rozenfeld, S., "Using The ISSN (International Serial
Standard Number) as URN (Uniform Resource Names) within an
ISSN-URN Namespace", RFC 3044, January 2001.
[RFC3187] Hakala, J. and H. Walravens, "Using International Standard
Book Numbers as Uniform Resource Names", RFC 3187,
October 2001.
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[RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
"Uniform Resource Names (URN) Namespace Definition
Mechanisms", BCP 66, RFC 3406, October 2002.
Appendix A. Draft Change Log
[[ RFC-Editor: Whole section to be deleted before RFC publication. ]]
A.1. draft-hakala-rfc3187bis-isbn-urn-00 to draft-ietf-urnbis-*-00
- formal updates for a WG draft;
- RFC 2288 now obsoleted and made Historic;
- added references to rfc2141bis and rfc3406bis;
- Sect.3 reorganized and amended: Namespace/Community Considerations;
- registration template adapted to rfc3406bis [-00];
- numerous editorial fixes and improvements.
A.2. draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01
- discussion on persistence altered, based on list discussion;
- changes and amendments to discussion of URN resolution services;
- discussion of fragment part usage added;
- broken link to ISBN manual fixed based on feedback from [ISBNORG];
- various editorial fixes and enhancements.
A.3. draft-ietf-urnbis-rfc3187bis-isbn-urn-01 to -02
- addressed review comments by LM and SM;
- cleanup of requirements language, but
- kept RFC 2119 terms where non-canonical/non-intuitive behavior of
resolver systems is specified;
- URLs for ISBN user manual (new public version) etc. updated;
- numerous editorial updates, fixes, and enhancements.
A.4. draft-ietf-urnbis-rfc3187bis-isbn-urn-02 to -03
- use of URI fragment is now allowed since they are not part of the
NSS;
- namespace registration template updated to conform with the -03
version of the rfc3406bis draft
- a few editorial updates, fixes, and enhancements.
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Authors' Addresses
Maarit Huttunen
The National Library of Finland
P.O. Box 26
Helsinki, Helsinki University FIN-00014
Finland
EMail: maarit.huttunen@helsinki.fi
Juha Hakala
The National Library of Finland
P.O. Box 15
Helsinki, Helsinki University FIN-00014
Finland
EMail: juha.hakala@helsinki.fi
Alfred Hoenes (editor)
TR-Sys
Gerlinger Str. 12
Ditzingen D-71254
Germany
EMail: ah@TR-Sys.de
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