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2 IETF URNbis WG M. Huttunen
3 Internet-Draft J. Hakala
4 Obsoletes: 2288,3187 (if approved) The National Library of Finland
5 Intended status: Standards Track A. Hoenes, Ed.
6 Expires: April 22, 2013 TR-Sys
7 October 19, 2012
9 Using International Standard Book Numbers as Uniform Resource Names
10 draft-ietf-urnbis-rfc3187bis-isbn-urn-03
12 Abstract
14 The International Standard Book Number, ISBN, is a widely used
15 identifier for monographic publications. Since 2001, the URN
16 (Uniform Resource Name) namespace "ISBN" has been reserved for ISBNs.
17 The namespace registration was performed in RFC 3187 and applied only
18 to the ISBN as specified in the ISO Standard 2108-1992, now known as
19 "ISBN-10". To allow for further growth in use, the successor ISO
20 Standard, ISO 2108:2005, has defined an expanded format for the ISBN,
21 known as "ISBN-13". This document defines how both of these ISBN
22 standard versions can be supported within the URN framework.
23 Moreover, additional query and fragment usage related information
24 required by RFC 2141bis has been included. An updated namespace
25 registration conformant to RFC 3406bis is provided. It describes how
26 both the old and the new ISBN format can share the same namespace.
28 This document replaces RFC 3187; it also obsoletes and moves to
29 Historic status the predecessor thereof, RFC 2288.
31 Discussion
33 This draft is based on individual work started in 2008. When the
34 URNBIS working group was launched, revision of the ISBN namespace
35 registration was included in its charter.
37 Comments are welcome and should be directed to the urn@ietf.org
38 mailing list or the authors.
39 [[ RFC-Editor: this clause to be deleted before RFC publication ]]
41 Status of This Memo
43 This Internet-Draft is submitted in full conformance with the
44 provisions of BCP 78 and BCP 79.
46 Internet-Drafts are working documents of the Internet Engineering
47 Task Force (IETF). Note that other groups may also distribute
48 working documents as Internet-Drafts. The list of current Internet-
49 Drafts is at http://datatracker.ietf.org/drafts/current/.
51 Internet-Drafts are draft documents valid for a maximum of six months
52 and may be updated, replaced, or obsoleted by other documents at any
53 time. It is inappropriate to use Internet-Drafts as reference
54 material or to cite them other than as "work in progress."
56 This Internet-Draft will expire on April 22, 2013.
58 Copyright Notice
60 Copyright (c) 2012 IETF Trust and the persons identified as the
61 document authors. All rights reserved.
63 This document is subject to BCP 78 and the IETF Trust's Legal
64 Provisions Relating to IETF Documents
65 (http://trustee.ietf.org/license-info) in effect on the date of
66 publication of this document. Please review these documents
67 carefully, as they describe your rights and restrictions with respect
68 to this document. Code Components extracted from this document must
69 include Simplified BSD License text as described in Section 4.e of
70 the Trust Legal Provisions and are provided without warranty as
71 described in the Simplified BSD License.
73 This document may contain material from IETF Documents or IETF
74 Contributions published or made publicly available before November
75 10, 2008. The person(s) controlling the copyright in some of this
76 material may not have granted the IETF Trust the right to allow
77 modifications of such material outside the IETF Standards Process.
78 Without obtaining an adequate license from the person(s) controlling
79 the copyright in such materials, this document may not be modified
80 outside the IETF Standards Process, and derivative works of it may
81 not be created outside the IETF Standards Process, except to format
82 it for publication as an RFC or to translate it into languages other
83 than English.
85 Table of Contents
87 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
88 2. Conventions used in this document . . . . . . . . . . . . . . 5
89 3. Fundamental Namespace and Community Considerations . . . . . . 5
90 3.1. The URN:ISBN Namespace . . . . . . . . . . . . . . . . . . 5
91 3.2. Community Considerations for ISBNs . . . . . . . . . . . . 5
92 4. International Standard Book Numbers . . . . . . . . . . . . . 6
93 4.1. Overview / Namespace Considerations . . . . . . . . . . . 6
94 4.1.1. ISBN-10 Structure . . . . . . . . . . . . . . . . . . 6
95 4.1.2. ISBN-13 Structure . . . . . . . . . . . . . . . . . . 7
96 4.1.3. Relation between ISBN-10 and ISBN-13 . . . . . . . . . 7
97 4.2. Encoding Considerations . . . . . . . . . . . . . . . . . 8
98 4.3. Resolution of ISBN-based URNs . . . . . . . . . . . . . . 8
99 4.3.1. General . . . . . . . . . . . . . . . . . . . . . . . 8
100 4.3.2. Practical Aspects . . . . . . . . . . . . . . . . . . 9
101 4.4. Additional Considerations . . . . . . . . . . . . . . . . 12
102 5. URN Namespace Registration and Use . . . . . . . . . . . . . . 13
103 5.1. URN Namespace ID Registration for the International
104 Standard Book Number (ISBN) . . . . . . . . . . . . . . . 13
105 6. Security Considerations . . . . . . . . . . . . . . . . . . . 18
106 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
107 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19
108 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19
109 9.1. Normative References . . . . . . . . . . . . . . . . . . . 19
110 9.2. Informative References . . . . . . . . . . . . . . . . . . 20
111 Appendix A. Draft Change Log . . . . . . . . . . . . . . . . . . 21
112 A.1. draft-hakala-rfc3187bis-isbn-urn-00 to
113 draft-ietf-urnbis-*-00 . . . . . . . . . . . . . . . . . . 21
114 A.2. draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01 . . . . . 21
115 A.3. draft-ietf-urnbis-rfc3187bis-isbn-urn-01 to -02 . . . . . 21
116 A.4. draft-ietf-urnbis-rfc3187bis-isbn-urn-02 to -03 . . . . . 21
118 1. Introduction
120 One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986],
121 [IANA-URI]) is 'URN' (Uniform Resource Name) as originally defined in
122 RFC 2141 [RFC2141] and now being formally specified in RFC 2141bis
123 [I-D.ietf-urnbis-rfc2141bis-urn]. Any identifier, when used within
124 the URN system, needs its own namespace. At the time of this
125 writing, there were over 45 registered URN namespaces (see
126 [IANA-URN]), one of which belongs to ISBN, International Standard
127 Book Number, as specified 2001 in RFC 3187 [RFC3187].
129 Since 2007, there have been two variants of ISBN in use; an outdated
130 one based on ISO 2108-1992 [ISO1] and a new one defined in ISO 2108-
131 2005 [ISO2]. These versions shall subsequently be called "ISBN-10"
132 and "ISBN-13", respectively. If what is said in this document
133 applies to both ISBN versions, the generic term "ISBN" is used.
135 As part of the validation process for the development of URNs, the
136 IETF URN working group agreed that it is important to demonstrate
137 that a URN syntax proposal can accommodate existing identifiers from
138 well established namespaces. One such infrastructure for assigning
139 and managing names comes from the bibliographic community.
140 Bibliographic identifiers function as names for objects that exist
141 both in print and, increasingly, in electronic formats. RFC 2288
142 [RFC2288] investigated the feasibility of using three identifiers
143 (ISBN, ISSN, and SICI -- see below) as URNs, with positive results;
144 however, it did not formally register corresponding URN namespaces.
145 This was in part due to the still evolving process to formalize
146 criteria for namespace definition documents and registration,
147 consolidated later in the IETF, first into RFC 2611 [RFC2611], then
148 into RFC 3406 [RFC3406], and now given by RFC 3406bis
149 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
151 URN Namespaces have subsequently been registered for both ISBN
152 (International Standard Book Number) and ISSN (International Serial
153 Standard Number) in RFCs 3187 [RFC3187] and 3044 [RFC3044],
154 respectively, but not for SICI (Serial Item and Contribution
155 Identifier), mainly due to the identifier's limited popularity.
157 Guidelines for using ISBN-10s (based on ISO 2108:1992) as URNs and
158 the original namespace registration have been published in RFC 3187
159 [RFC3187]. The RFC at hand replaces RFC 3187; sections related to
160 ISBN-13 have been added, all ISBN-10 information has been updated,
161 and the namespace registration revised to make it compliant with both
162 ISBN versions and the stipulations of RFC 3406bis
163 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
165 2. Conventions used in this document
167 When spelled in all-capitals as in this paragraph, the key words
168 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
169 "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document
170 are to be interpreted as described in BCP 14 [RFC2119].
172 "ISBN-10" refers to the original, 10-digit ISBN scheme specified in
173 ISO 2108-1992 [ISO1].
175 "ISBN-13" refers to the current, 13-digit ISBN scheme specified in
176 ISO 2108-2005 [ISO2].
178 "URN:ISBN" is used as a shorthand for "ISBN-based URN".
180 3. Fundamental Namespace and Community Considerations
182 3.1. The URN:ISBN Namespace
184 ISBN is a well established standard identifier system for monographic
185 publications. Therefore, any useful and deployable method for
186 identifying these entities for Internet-wide reference and making
187 their metadata available on the Internet needs to be based on ISBNs.
189 3.2. Community Considerations for ISBNs
191 ISBNs are assigned under the auspices of the International ISBN
192 Agency [ISBNORG] and national/regional ISBN agencies. ISBN
193 assignment is a well managed and understood process, but as in any
194 process administered by humans, errors do take place. If so, there
195 are procedures in place for fixing the incorrect ISBNs.
197 Books are finite objects, which may consist of (logical) component
198 resources such as chapters or short stories / novellas. Such
199 component resources can get an ISBN if and only if they are for sale
200 independently. For example, a user could purchase either the entire
201 short story collection, or just one short story. Either way, he gets
202 a file with the relevant content. Logical components can also be
203 represented in the physical structure of the document; for instance,
204 chapters of a digital book may be encoded into its HTML structure.
205 Then and only then an URI fragment can be attached to the URN:ISBN.
206 The entire resource will be retrieved, but the fragment will be
207 applied by the browser to take the user into the desired point within
208 the document. Please note that according to the ISBN standard, ISBN
209 MUST be assigned to a single manifestation of the resource. An ISBN
210 given to the PDF version of the book cannot be reused to the EPUB 3
211 version.
213 The ISBN standard does not allow augmentation of the ISBN itself with
214 an identification of a physical component resource of a book.
215 However, if a fragment part is added to a URI reference to an URN:
216 ISBN, the namespace specific string is still the base ISBN only, and
217 lexically, the URN with and without the URI fragment identifier are
218 equivalent.
220 For the ISBN community, the use of URI fragment identifiers provides
221 additional functionality that would not be easily available in any
222 other way. An ISBN-13 can be assigned to logical component
223 resources, but this feature has not been used extensively. URI
224 fragment offers a light-weight (technically and administratively)
225 solution to the users to pinpoint component resources within
226 electronic manifestations of books, provided that these components
227 have been encoded in an appropriate manner.
229 The materials identified by an ISBN can exist only in printed or
230 other physical form, not as digital resources accessible in the WEB;
231 and even if an electronic book exists, its access rights may be
232 limited. ISBN-based URN resolution services are expected to support
233 a wide variety of information services related to books. Hence, when
234 the identified manifestation of the book cannot be supplied, the
235 applicable URN:ISBN resolver SHOULD supply descriptive and rights
236 metadata about the relevant manifestation; the resolver MAY also
237 provide links to other manifestations of the same work, or to related
238 works.
240 The next section presents an overview of the application of the URN:
241 ISBN namespace and the principles, and systems used, for the
242 resolution of ISBN-based URNs.
244 4. International Standard Book Numbers
246 4.1. Overview / Namespace Considerations
248 An International Standard Book Number (ISBN) identifies a product
249 form or edition of a monographic publication. ISO 2108 requires that
250 each product form (e.g. hardcover, paperback, PDF) has its own ISBN.
252 4.1.1. ISBN-10 Structure
254 The ISBN-10 is defined by the ISO Standard 2108-1992 [ISO1]. It is a
255 ten-digit number (the last "digit" can be the letter "X" as well)
256 that is divided into four variable-length parts usually separated by
257 hyphens when printed. Note that these hyphens can be removed; ISBNs
258 with and without the hyphens are lexically equivalent. The parts are
259 as follows (in this order):
261 o a group identifier that specifies a group of publishers, based on
262 national scope, geographic scope, or some other criteria;
264 o the publisher identifier;
266 o the title identifier; and
268 o a modulo 11 check digit, using X instead of 10; the details of the
269 calculation are specified in the ISO Standard [ISO1].
271 ISBN-10s were assigned starting from the 1970s until the introduction
272 of ISBN-13 in January 2007.
274 4.1.2. ISBN-13 Structure
276 ISBN-13 is defined by the ISO Standard 2108-2005 [ISO2]. The ISBN-13
277 is a thirteen-digit number that is divided into five parts usually
278 separated by hyphens when printed. The first and the last part have
279 a fixed lenght, but the other parts have variable length. These
280 parts are as follows (in this order):
282 o an ISBN-13 prefix element -- a 3-digit prefix specified by the
283 International ISBN Agency; at the time of this writing, applicable
284 values were 978 and 979; future versions of the standard may
285 define additional values;
287 o a registration group element that specifies the registration
288 group; it identifies the national, geographic, language, or other
289 such grouping within which one or more ISBN Agencies operate;
291 o the registrant element;
293 o the publication element; and
295 o a modulo 10 check digit; the details of the calculation are
296 specified in the ISO Standard [ISO2].
298 4.1.3. Relation between ISBN-10 and ISBN-13
300 The structural differences between the ISBN-10 and ISBN-13 are the
301 prefix element (which does not exist in the ISBN-10) and the check
302 digit calculation algorithm, which is modulo 11 in ISBN-10 and modulo
303 10 in ISBN-13.
305 Further, the terminology in ISBN-10 differs substantially from the
306 terminology applied in ISBN-13. In this document, ISBN-13
307 terminology shall be used from now on; for a reader used to ISBN-10
308 terminology, the following mapping may be useful:
310 o ISBN-10 group identifier <-> ISBN-13 registration group element
311 under prefix 978;
313 o ISBN-10 publisher identifier <-> ISBN-13 registrant element;
315 o ISBN-10 title identifier <-> ISBN-13 publication element.
317 Any ISBN-10 can be converted to ISBN-13 form (and retrospective
318 conversion is the recommended practice in ISO 2108:2005) by mapping
319 it into the ISBN-13 prefix-978 range and recalculating the check
320 digit. Any application that processes ISBN-based URNs MUST be
321 prepared to deal with both kinds of ISBNs, since instances of ISBN-10
322 numbers will persist that cannot be converted to the new form (e.g.,
323 ISBNs imprinted in books). ISBN-13s using prefix element 979 cannot
324 be converted back to ISBN-10, since under this prefix, ISBNs group
325 identifiers will be re-assigned from scratch. New books may still
326 have ISBN-10 alongside ISBN-13 for practical reasons, but only as
327 long as the prefix element in ISBN-13 is 978.
329 4.2. Encoding Considerations
331 Embedding ISBNs within the URN framework does not present encoding
332 problems, since all of the characters that can appear in an ISBN are
333 valid in the namespace-specific string (NSS) part of the URN.
334 Percent-encoding, as described in RFC 2141bis
335 [I-D.ietf-urnbis-rfc2141bis-urn], is never needed. In order to
336 improve readability of the NSS, hyphens MAY be used.
338 Example 1: URN:ISBN:978-0-395-36341-6
340 Example 2: URN:ISBN:951-0-18435-7
342 Example 3: URN:ISBN:951-20-6541-X
344 Example 3: URN:ISBN:951206541X
346 4.3. Resolution of ISBN-based URNs
348 4.3.1. General
350 For URN resolution purposes, all elements except the check digit (0-9
351 for ISBN-13, and 0-9 or X for legacy ISBN-10) must be taken into
352 account. The registration group and registrant element assignments
353 are managed in such a way that the hyphens are not needed to parse
354 the ISBN unambiguously into its constituent parts. However, the ISBN
355 is normally transmitted and displayed with hyphens to make it easy
356 for humans to recognize these elements without having to make
357 reference to or have knowledge of the number assignments for
358 registration group and registrant elements. In ISBN-10, registration
359 group element codes such as 91 for Sweden were unique. In ISBN-13,
360 only the combinations of prefix and registration group elements are
361 guaranteed to be unique. 978-951 and 978-952 both mean Finland, but
362 979-951 and 979-952 almost certainly will not (once they will be
363 assigned in the future); at the time of this writing, registration
364 group element(s) for Finland are not yet known for ISBNs starting
365 with 979.
367 The Finnish URN registry is maintained by the national library. The
368 service is capable of resolving ISBN-based URNs. URNs starting with
369 URN:ISBN:978-951 or URN:ISBN:978-952 are mapped into appropriate URL
370 addresses in a table maintained within the registry. Applications,
371 such as the national bibliography or the open archive of a
372 university, can use the URN as the persistent address of the
373 resource. There is just one place (the URN registry) where the
374 address is mapped to one or more physical locations.
376 ISBN-13 prefix / registration group element combinations (and the
377 corresponding ISBN-10 registration group identifiers, if any) usually
378 designate a country, but occasionally a single combination / ISBN-10
379 group identifier is used to indicate a language area. For instance,
380 "978-3" (or "3" in ISBN-10) is utilised in Germany, Austria, and the
381 German speaking parts of Switzerland. As of this writing, there are
382 two regional registration groups: "978-976" is used in the Caribbean
383 community and "978-982" in the South Pacific (see [ISBN_PREFIX]).
385 Note that the prefix and registration group element combination
386 "979-3" has not yet been assigned. There is no intention to allocate
387 the registration group elements in the same way as was done with
388 ISBN-10.
390 The registrant element may or may not be used for resolution
391 purposes, depending on whether individual publishers have set up
392 their resolution services.
394 The publication element shall enable targeting the individual
395 publication.
397 4.3.2. Practical Aspects
399 Due to the lack of URN support in, e.g., web browsers, the URNs are
400 usually expressed as URLs when embedded in documents. The Finnish
401 URN registry is located at , and URNs are therefore
402 expressed in the form http://urn.fi/. For example, the URI
403 identifies Sami Nurmi's
404 doctoral dissertation "Aspects of Inflationary Models at Low Energy
405 Scales".
407 Any national URN registry can resolve URN:ISBNs with foreign
408 registration group element values if a) there is a URN:ISBN
409 resolution service for that country, b) the national resolution
410 service is aware of the existence of the foreign service and how to
411 find it, and c) the two resolution services can communicate with one
412 another. The PERSID project () developed
413 such an infrastructure for the URN:NBN namespace.
415 Alternatively, instead of linking the national resolvers together, it
416 is also possible to build international resolvers that copy
417 resolution data from several national services, or to create a way
418 station which will enable the resolvers to communicate with one
419 another. We can assume that the network of URN:ISBN resolvers will
420 grow, and at the same time the set of services they support will also
421 grow and become more diverse. Such development might make these
422 union resolvers and way stations more important.
424 If a registration group element does not identify a single country
425 but a language area, there are at least two means for locating the
426 correct national bibliography. First, it is possible to define a
427 cascade of URN registries -- for instance, the German, Austrian, and
428 Swiss national registries, in this order --, which collectively is
429 aware of resolution services such as national bibliographies for
430 ISBN-13s starting with "978-3". If the German registry is not able
431 to find an authoritative resolution service, the request could be
432 passed on to the Austrian one, and if there are still no hits,
433 finally to the Swiss service.
435 Second, the registrant element ranges assigned to the publishers in
436 Germany, Austria, and Switzerland by the respective ISBN Agencies
437 could be defined directly into the national registries. This method
438 would be more efficient than cascading, since the correct resolution
439 service would be known immediately. The choice between these two and
440 possible other options should be made when the establishment of the
441 European network of URN registries reaches this level of maturity.
443 In some exceptional cases -- notably in the US and in the UK, where
444 international companies do a significant portion of publishing -- the
445 information provided by the group identifier may not always be fully
446 reliable. For instance, some monographs published in New York by
447 international publishing companies may get an ISBN with the
448 registration group element "3". This is technically appropriate when
449 the headquarters or one of the offices of the publisher is located in
450 Germany.
452 Information about such a book may not always be available in the
453 German national bibliography, but via the Library of Congress
454 systems. Unfortunately, the German/Austrian/Swiss URN registries
455 that should in this case be contacted may not be aware of the
456 appropriate resolution service.
458 However, the problem posed by the international publishers may be
459 less severe than it looks. Some international publishers (Springer,
460 for example) give the whole production to the national library of
461 their home country as legal deposit, no matter which country the book
462 was published. Thus everything published by Springer in New York
463 with registration group element "3" should be resolvable via the
464 German national bibliography. On the other hand, when these
465 companies give their home base also as a place of publication, the
466 "home" national library requires the legal deposit.
468 A large union catalogue, such as WorldCat maintained by OCLC
469 [OCLC-WC] can be used to complement the resolution services provided
470 in the national level, or as the default service, if no national
471 services exist or are known to the registry from which the query
472 originates.
474 Due to the semantic structure of ISBN-13, the registrant element can
475 be used as a "hint". Technically, it is possible to establish a
476 number of URN resolution services maintained by different kinds of
477 organizations. For instance, "978-951-0" is the unique ISBN
478 registrant element of the largest publisher in Finland, Sanoma-WSOY.
479 Resolution requests for ISBNs starting with "978-951-0" can be passed
480 to and dealt with the publisher's server, if and when it is made URN-
481 aware. In such a case, resolving the same URN in multiple locations
482 MAY provide different services; the national bibliography might be
483 able to provide bibliographic information only, while the publisher
484 can provide the book itself, on its own terms. Users can expect
485 Resolution services to co-exist and complement one another. The same
486 ISBN can be resolved both as URN and as a Digital Object Identifier
487 (DOI) [DOIHOME]. URN-based services hosted by, e.g., a national
488 library, might provide only bibliographic metadata, whereas a service
489 based on the DOI system provided by the publisher may supply the
490 book, parts of the book or various other services.
492 Persistence is one of the key features for any persistent identifier
493 system. There are three inter-related aspects of persistence that
494 need to be discussed: persistence of the resource itself, persistence
495 of the identifier, and persistence of the URN-based resolvers.
497 ISBNs are assigned to manifestations (physical embodiments) of books.
498 Thus each digital version of a book (PDF, XML and so on) MUST receive
499 its own ISBN. This quarantees that if URI fragment is added to the
500 NSS, it remains functional as long as the digital manifestation is
501 available.
503 Printed books and library catalogues are persistent, so even after
504 500 years, a URN:ISBN identifying a printed book can resolve to a
505 bibliographic description of the book, which usually tells where the
506 book can be found in, e.g., libraries' collections.
508 With digital books things get more complicated. According to ISO
509 2108, each product form must have a separate ISBN. Since digital
510 manifestations are not long-lived, future users who try to find and
511 old version of an electronic book, are not likely to find that
512 version. Instead there will be several modernized versions of the
513 resource, produced via migration. There might also be a printed book
514 with similar intellectual content. These manifestations of a book
515 SHOULD be interlinked (using, for instance, the work level metadata
516 record with URN:ISBN links to all manifestations) so as to make a
517 user aware of the existence of alternative sources. Such
518 interlinking enables the users to retrieve manifestations which match
519 their interests best. Different users are likely to have different
520 preferences. While some users prefer a modern manifestation which no
521 longer has the authentic look and feel, there are users who want the
522 "first edition" even if it requires digital archaeology for access.
524 Persistence of URN:ISBN resolvers themselves is mainly an
525 organizational issue, related to the persistence of organizations
526 maintaining them. URN:ISBN resolution services are currently
527 supplied by several national libraries to enable access to their
528 legal deposit collections. These URN:ISBN resolution services are
529 likely to be relatively persistent.
531 4.4. Additional Considerations
533 The basic guidelines for assigning ISBNs to electronic resources are
534 the following:
536 o Product form and the means of delivery are irrelevant to the
537 decision whether a product needs an ISBN or not. If the content
538 meets the requirements of the standard, it gets an ISBN, no matter
539 what the file format or the delivery system.
541 o Each product form (manifestation) of a digital publication should
542 have a separate ISBN. The definition of a new edition is normally
543 based on one of the two criteria:
545 * A change in the kind of packaging involved: the hard cover
546 edition, the paperback edition and the library-binding edition
547 would each get a separate ISBN. The same applies to different
548 versions of digital books.
550 * A change in the text, excluding packaging or minor changes such
551 as correcting a spelling error. Again, this criterion applies
552 regardless of whether the publication is in printed or in
553 digital form.
555 Although these rules seem clear, their interpretation may vary. As
556 already RFC 2288 [RFC2288] pointed out,
558 The choice of whether to assign a new ISBN or to reuse an existing
559 one when publishing a revised printing of an existing edition of a
560 work or even a revised edition of a work is somewhat subjective.
561 Practice varies from publisher to publisher (indeed, the
562 distinction between a revised printing and a new edition is itself
563 somewhat subjective). The use of ISBNs within the URN framework
564 simply reflects these existing practices.
566 Since ISBN assignment is a manual process mistakes do happen. For
567 instance, ISBNs are occasionally re-used for another book or another
568 manifestation of the same book. Such human errors are relatively
569 rare and do not threaten or undermine the value of the ISBN system as
570 a whole. They are not a serious risk to the URN resolution service
571 based on ISBNs.
573 Libraries routinely correct ISBN mistakes. Their catalogs provide
574 cross references ("incorrect ISBN -> correct ISBN"). This MUST be
575 taken into account in the URN resolution process. Further details on
576 the process of assigning ISBNs can be found in Section 5 (Namespace
577 registration) below.
579 5. URN Namespace Registration and Use
581 The formal URN Namespace Identifier Registration for the pre-2005
582 version of the International Standard Book Number (ISBN) was done in
583 RFC 3187 [RFC3187].
585 The new ISBN standard does not require a new namespace, but the
586 registration is renewed here. The registrant organization has moved
587 from Staatsbibliothek zu Berlin - Preussischer Kulturbesitz to The
588 International ISBN Agency, London, U.K. Moreover, the description of
589 the NSS and resolution details have been amended.
591 5.1. URN Namespace ID Registration for the International Standard Book
592 Number (ISBN)
594 This registration describes how International Standard Book Numbers
595 (ISBN) can be supported within the URN framework.
597 [ RFC Editor: please replace "XXXX" in all instances of "RFC XXXX"
598 below by the RFC number assigned to this document. ]
600 Namespace ID: ISBN
602 This Namespace ID has already been assigned to the International
603 Standard Book Number in January 2001 when the namespace was
604 initially registered.
606 Kind of named resources:
608 Manifestations of monographic publications.
610 Registration Information:
612 Version: 2
613 Date: 2012-10-19
615 Declared registrant of the namespace:
617 Registering Organization: The International ISBN Agency
619 Designated Contact Person:
620 Name: Ms. Stella Griffiths
621 Affiliation: Executive Director, The International ISBN Agency
622 Email: info@isbn-international.org
623 Postal: EDItEUR, 39-41 North Road, London, N7 9DP, U.K.
624 Web URL:
626 Declaration of syntactic structure of NSS part:
628 The namspace-specific string of 'ISBN' URNs is either an ISBN-13
629 (see Section 4.1.2 of RFC XXXX) or an ISBN-10 (see Section 4.1.1
630 of RFC XXXX); the former is preferred.
632 Example 1: URN:ISBN:978-0-395-36341-6
633 Example 2: URN:ISBN:951-0-18435-7
634 Example 3: URN:ISBN:951-20-6541-X
635 Example 4: URN:ISBN:951206541X
637 Relevant ancillary documentation:
639 The ISBN (International Standard Book Number) is a unique machine-
640 readable identification number, which marks any edition of a book
641 unambiguously. This number is defined in ISO Standard 2108:2005.
642 ISBNs has been in use for more than 30 years and they have
643 revolutionised the international book-trade. 170 countries and
644 territories are officially ISBN members.
646 The administration of the ISBN system is carried out on three
647 levels:
648 International agency,
649 Group agencies,
650 Publishers.
652 The International ISBN agency is located in London. The main
653 functions of the Agency are:
655 * To promote, co-ordinate and supervise the world-wide use of the
656 ISBN system.
658 * To approve the definition and structure of group agencies.
660 * To allocate group identifiers to group agencies.
662 * To advise on the establishment and functioning of group
663 agencies.
665 * To advise group agencies on the allocation of international
666 publisher identifiers.
668 * To publish the assigned group numbers and publisher prefixes in
669 up-to-date form.
671 Detailed information about ISBN usage can be found from the ISBN
672 Users' Manual [ISBN_UM]. A shorter introduction to ISBN usage can
673 be found from the ISBN FAQ web pages [ISBN_FAQs], which also
674 include guidelines for the assignment of ISBNs to e-books.
676 Conformance with URN Syntax:
678 Legal ISBN characters are 0-9 and hyphen for ISBN-13 and 0-9,
679 hyphen, and X for ISBN-10. No percent-encoding is needed. Hyphen
680 carries no semantic content and MAY be dropped from the NSS.
682 Rules for Lexical Equivalence of NSS part:
684 ISBN numbers are usually printed with the letters 'ISBN' and a
685 single blank preceding the ISBN proper (for instance: ISBN 951-
686 746-795-8). The data preceding the ISBN MUST NOT be included in
687 the NSS. No percent-encoding is needed.
689 Prior to comparing the NSS of two ISBN-based URNs for equivalence,
690 all hyphens, if present, MUST be removed and letter 'X'
691 capitalized. Prior to comparing a URN based on ISBN-10 with a URN
692 based on ISBN-13, the ISBN-10 MUST be converted to the ISBN-13
693 form. This step is necessary since it is not possible to know if
694 the ISBN-10s have been converted to the new form; libraries SHOULD
695 keep the old ISBN since it is the one printed in books published
696 prior to 2007, while publishers MAY convert the old identifiers
697 originally assigned in ISBN-10 form and use the equivalent ISBN-
698 13s in unchanged reprints of the books, which according to the
699 ISBN assignment rules should not receive a new ISBN.
701 Note that the prefix "URN:ISBN:" is case-insensitive; generic URI
702 parsing and comparison software frequently uses lower case as the
703 canonical (normalized) form.
705 Note that URI fragment and/or query, if present, are not part of
706 the NSS and MUST be removed before the lexical equivalence is
707 determined. Thus urn:isbn:978-951-1-25645-8,
708 urn:isbn:978-951-1-25645-8?s=U2C and
709 urn:isbn:978-951-1-25645-8#chapter2 are lexically equivalent,
710 although the URN resolvers will treat them in a different manner.
712 The URNs are equivalent if the normalized forms compare equal.
714 Usage of query instructions:
716 URN:ISBN resolvers MAY support several global services. Some of
717 them have been specified in RFC 2483; some remain unspecified.
718 Examples of existing relevant services are URI to URL or URLs, URI
719 to URN or URNs, URI to resource or resources, and URI to URC or
720 URCs. The component directive is relevant especially to the URI
721 to URC service, where it can be used to, e.g., indicate the
722 preferred metadata format or the completeness of the metadata
723 record or the metadata content requested such as table of
724 contents. A URN resolver maintained by a national library may
725 consult for instance the national bibliography, digital asset
726 management systems and digital preservation systems to supply
727 these services.
729 Examples of services which may be specified and implemented in the
730 future: request the oldest and most original manifestation of the
731 resource; request the latest version of the resource and request
732 metadata related to the work.
734 Usage of fragment part:
736 If URI-to-resource service is used and the media type supports the
737 use of URI fragment parts, the users can ustilize that to indicate
738 locations within the identified resources since ISBNs are assigned
739 to one and one only manifestation of a resource.
741 The URN:ISBN Namespace does not impose any restrictions of its own
742 on the fragment identifiers allowed, beyond what the respective
743 media type admits.
745 Identifier uniqueness considerations:
747 ISBN is a unique identifier. An ISBN, once it has been assigned,
748 MUST NOT be re-used for another book or another product form
749 (manifestation) of the same book.
751 URN:ISBNs inherit the uniqueness properties from ISBNs. Please
752 note that the same ISBN can be used in another persistent
753 identifier system, such as DOI or Handle. The resulting
754 persistent identifier is likely to provide different resolution
755 services than URN:ISBN.
757 If there are multiple manifestations of a single literary work
758 such as a novel, each one MUST receive a different ISBN. ISTC
759 (International Standard Text Code, ISO 21047-2009) enables
760 identification of textual works. See
761 for more information. Annex
762 E of the ISTC standard describes the relations between ISTC and
763 publication identifiers such as ISBN.
765 Identifier persistence considerations:
767 ISBN is a persistent identifier. Once a book has received an
768 ISBN, it MUST NOT get a new ISBN.
770 URN:ISBNs inherit the persistence properties from ISBNs.
772 Since ISBNs are attached to manifestations, a URI fragment, if
773 attached to the URN:ISBN, is as persistent as the ISBN itself.
774 Support for URI query is likely to be less persistent, since it is
775 dependent on applications supporting the functionality requested.
777 Process of identifier assignment:
779 Assignment of ISBNs is controlled, and URN:ISBNs inherit this
780 property. There are three levels of control: the international
781 agency, group agencies that typically operate in the national
782 level, and finally each publisher is responsible of using the ISBN
783 system correctly. Small publishers may demand ISBN numbers one at
784 a time by contacting the ISBN group agency. Large publishers
785 receive ISBN blocks from which they allocate ISBNs to the books
786 according to the ISBN assignment rules.
788 Process for identifier resolution:
790 See Section 4.3 of RFC XXXX.
792 Validation mechanism:
794 The check digit helps to assure the correctness of an ISBN number
795 assigned for a book when it has been entered or processed.
796 Applications processing bibliographic data such as integrated
797 library systems MAY check the correctness of both ISBN-10 and
798 ISBN-13 (and make conversions between the two). If the number is
799 wrong due to, e.g., a typing error made by a publisher, a correct
800 ISBN SHOULD be assigned afterwards. Although the book will only
801 contain the wrong number, national bibliography and system used by
802 the book trade often will contain both the wrong and new, correct
803 ISBN number.
805 Scope:
807 ISBN is a global identifier system used for identification of
808 monographic publications. It is very widely used and supported by
809 the publishing industry.
811 6. Security Considerations
813 This document proposes means of encoding ISBNs within the URN
814 framework. An ISBN-based URN resolution service is depicted here
815 both for ISBN-10 and ISBN-13, but only in a fairly generic level;
816 thus questions of secure or authenticated resolution mechanisms are
817 excluded. It does not deal with means of validating the integrity or
818 authenticating the source or provenance of URNs that contain ISBNs.
819 Issues regarding intellectual property rights associated with objects
820 identified by the ISBNs are also beyond the scope of this document,
821 as are questions about rights to the databases that might be used to
822 construct resolvers.
824 Beyond the generic security considerations laid out in the underlying
825 documents listed in the Normative References (Section 9.1), no
826 specific security threats have been identified for ISBN-based URNs.
828 7. IANA Considerations
830 IANA is asked to update the existing registration of the Formal URN
831 Namespace 'ISBN' using the template given above in Section 5.1, which
832 follows the outline specified in RFC 3406bis
833 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg].
835 8. Acknowledgements
837 This draft version is the outcome of work started in 2008 and brought
838 to the IETF in 2010 to launch a much larger effort to revise the
839 basic URN RFCs. The aim in the IETF is to bring these RFCs in
840 alignment with the current URI Standard (STD 63, RFC 3986), ABNF, and
841 IANA guidelines. The participants of project PERSID
842 () contributed significantly to the standards
843 work.
845 Leslie Daigle has provided valuable guidance in the initial draft
846 stage of this memo.
848 Stella Griffiths has advised and guided the development of this
849 document, has verified the technical content from the director's view
850 of the International ISBN Agency, and provided valuable comments.
852 Larry Masinter, Subramanian Moonesamy, Julian Reschke, and other
853 participants of the URNbis working group have provided review
854 comments and text suggestions that have improved this document.
856 9. References
858 9.1. Normative References
860 [I-D.ietf-urnbis-rfc2141bis-urn]
861 Hoenes, A., "Uniform Resource Name (URN) Syntax",
862 draft-ietf-urnbis-rfc2141bis-urn-03 (work in progress),
863 October 2012.
865 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]
866 Hoenes, A., "Defining Uniform Resource Name (URN)
867 Namespaces", draft-ietf-urnbis-rfc3406bis-urn-ns-reg-03
868 (work in progress), October 2012.
870 [ISO1] ISO, "Information and documentation - The International
871 Standard Book Number (ISBN)", ISO 2108-1992, 1992.
873 [ISO2] ISO, "Information and documentation - The International
874 Standard Book Number (ISBN)", ISO 2108-2005, 2005.
876 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
877 Requirement Levels", BCP 14, RFC 2119, March 1997.
879 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
880 Resource Identifier (URI): Generic Syntax", STD 66,
881 RFC 3986, January 2005.
883 9.2. Informative References
885 [DOIHOME] International DOI Foundation, "The Digital Object
886 Identifier System", .
888 [IANA-URI]
889 IANA, "URI Schemes Registry",
890 .
892 [IANA-URN]
893 IANA, "URN Namespace Registry",
894 .
896 [ISBNORG] International ISBN Agency, "",
897 .
899 [ISBN_FAQs]
900 International ISBN Agency, "ISBN Prefix Ranges",
901 .
903 [ISBN_PREFIX]
904 International ISBN Agency, "ISBN Prefix Ranges",
905 .
907 [ISBN_UM] International ISBN Agency, "ISBN Users' Manual",
908 .
910 [OCLC-WC] OCLC WorldCat, "WorldCat.org: The World's Largest Library
911 Catalog", .
913 [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
915 [RFC2288] Lynch, C., Preston, C., and R. Jr, "Using Existing
916 Bibliographic Identifiers as Uniform Resource Names",
917 RFC 2288, February 1998.
919 [RFC2611] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
920 "URN Namespace Definition Mechanisms", BCP 33, RFC 2611,
921 June 1999.
923 [RFC3044] Rozenfeld, S., "Using The ISSN (International Serial
924 Standard Number) as URN (Uniform Resource Names) within an
925 ISSN-URN Namespace", RFC 3044, January 2001.
927 [RFC3187] Hakala, J. and H. Walravens, "Using International Standard
928 Book Numbers as Uniform Resource Names", RFC 3187,
929 October 2001.
931 [RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
932 "Uniform Resource Names (URN) Namespace Definition
933 Mechanisms", BCP 66, RFC 3406, October 2002.
935 Appendix A. Draft Change Log
937 [[ RFC-Editor: Whole section to be deleted before RFC publication. ]]
939 A.1. draft-hakala-rfc3187bis-isbn-urn-00 to draft-ietf-urnbis-*-00
941 - formal updates for a WG draft;
942 - RFC 2288 now obsoleted and made Historic;
943 - added references to rfc2141bis and rfc3406bis;
944 - Sect.3 reorganized and amended: Namespace/Community Considerations;
945 - registration template adapted to rfc3406bis [-00];
946 - numerous editorial fixes and improvements.
948 A.2. draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01
950 - discussion on persistence altered, based on list discussion;
951 - changes and amendments to discussion of URN resolution services;
952 - discussion of fragment part usage added;
953 - broken link to ISBN manual fixed based on feedback from [ISBNORG];
954 - various editorial fixes and enhancements.
956 A.3. draft-ietf-urnbis-rfc3187bis-isbn-urn-01 to -02
958 - addressed review comments by LM and SM;
959 - cleanup of requirements language, but
960 - kept RFC 2119 terms where non-canonical/non-intuitive behavior of
961 resolver systems is specified;
962 - URLs for ISBN user manual (new public version) etc. updated;
963 - numerous editorial updates, fixes, and enhancements.
965 A.4. draft-ietf-urnbis-rfc3187bis-isbn-urn-02 to -03
967 - use of URI fragment is now allowed since they are not part of the
968 NSS;
969 - namespace registration template updated to conform with the -03
970 version of the rfc3406bis draft
971 - a few editorial updates, fixes, and enhancements.
973 Authors' Addresses
975 Maarit Huttunen
976 The National Library of Finland
977 P.O. Box 26
978 Helsinki, Helsinki University FIN-00014
979 Finland
981 EMail: maarit.huttunen@helsinki.fi
983 Juha Hakala
984 The National Library of Finland
985 P.O. Box 15
986 Helsinki, Helsinki University FIN-00014
987 Finland
989 EMail: juha.hakala@helsinki.fi
991 Alfred Hoenes (editor)
992 TR-Sys
993 Gerlinger Str. 12
994 Ditzingen D-71254
995 Germany
997 EMail: ah@TR-Sys.de