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The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 19, 2012) is 4207 days in the past. Is this intentional? 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'ISO2' -- Obsolete informational reference (is this intentional?): RFC 2141 (Obsoleted by RFC 8141) -- Obsolete informational reference (is this intentional?): RFC 2611 (Obsoleted by RFC 3406) -- Obsolete informational reference (is this intentional?): RFC 3044 (Obsoleted by RFC 8254) -- Obsolete informational reference (is this intentional?): RFC 3187 (Obsoleted by RFC 8254) -- Obsolete informational reference (is this intentional?): RFC 3406 (Obsoleted by RFC 8141) Summary: 0 errors (**), 0 flaws (~~), 6 warnings (==), 12 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 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