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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Hakala 3 Internet-Draft The National Library of Finland 4 Obsoletes: 3188 (if approved) June 14, 2018 5 Intended status: Informational 6 Expires: December 16, 2018 8 Using National Bibliography Numbers as Uniform Resource Names 9 draft-hakala-urn-nbn-rfc3188bis-02 11 Abstract 13 National Bibliography Numbers (NBNs) are used by the national 14 libraries and other organizations in order to identify resources in 15 their collections. NBNs are usually applied to resources that are 16 not catered for by established (standard) identifier systems such as 17 ISBN. 19 A URN (Uniform Resource Names) namespace for NBNs was established in 20 2001 in RFC 3188. Since then, a number of European national 21 libraries have implemented URN:NBN-based systems. 23 This document replaces RFC 3188 and defines how NBNs can be supported 24 within the updated URN framework. A revised namespace registration 25 (version 4) compliant to RFC 8141 is included. 27 Status of This Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at https://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on December 16, 2018. 44 Copyright Notice 46 Copyright (c) 2018 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (https://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 62 1.1. Discussion list . . . . . . . . . . . . . . . . . . . . . 5 63 2. Conventions used in this document . . . . . . . . . . . . . . 5 64 3. Fundamental Namespace and Community Considerations for NBN . 5 65 3.1. The URN:NBN Namespace . . . . . . . . . . . . . . . . . . 5 66 3.2. Community Considerations for NBNs . . . . . . . . . . . . 6 67 4. National Bibliography Number URNs . . . . . . . . . . . . . . 7 68 4.1. Assignment . . . . . . . . . . . . . . . . . . . . . . . 7 69 4.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 8 70 4.2.1. Usage of r-component and q-component . . . . . . . . 10 71 4.2.2. Usage of f-component . . . . . . . . . . . . . . . . 10 72 4.3. Encoding Considerations and Lexical Equivalence . . . . . 10 73 4.4. Resolution and Persistence of NBN-based URNs . . . . . . 11 74 4.5. Additional considerations . . . . . . . . . . . . . . . . 13 75 5. URN Namespace ID (NID) Registration for the National 76 Bibliography Number (NBN) . . . . . . . . . . . . . . . . . . 13 77 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 78 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 79 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 80 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15 81 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 82 10.1. Normative References . . . . . . . . . . . . . . . . . . 15 83 10.2. Informative References . . . . . . . . . . . . . . . . . 16 84 Appendix A. Significant Changes from RFC 3188 . . . . . . . . . 18 85 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 18 86 B.1. draft-hakala-rfc3188bis-nbn-urn-00 to draft-ietf- 87 urnbis-*-00 . . . . . . . . . . . . . . . . . . . . . . . 18 88 B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01 . . . . . 19 89 B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02 . . . . . 19 90 B.4. draft-ietf-urnbis-rfc3188bis-nbn-urn-02 to -03 . . . . . 20 91 B.5. draft-ietf-urnbis-rfc3188bis-nbn-urn-03 to -04 . . . . . 20 92 B.6. draft-ietf-urnbis-rfc3188bis-nbn-urn-04 (2012-10-22) to 93 draft-hakala-urn-nbn-rfc3188bis-00 . . . . . . . . . . . 20 94 B.7. draft-hakala-urn-nbn-rfc3188bis-00 (2018-06-02) to draft- 95 hakala-urn-nbn-rfc3188bis-01 . . . . . . . . . . . . . . 21 96 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 21 98 1. Introduction 100 One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986], 101 [IANA-URI]) is 'URN' (Uniform Resource Name). URNs were originally 102 defined in RFC 2141 [RFC2141]. In 2017, a revision was adopted with 103 new definitions and registration procedures [RFC8141]. Any 104 traditional identifier, when used within the URN system, must have a 105 namespace of its own, registered with IANA [IANA-URN]. National 106 Bibliography Number (NBN) is one such namespace, specified in 2001 in 107 RFC 3188 [RFC3188]. 109 This document describes the syntax and usage of NBN URNs, and updates 110 the registration of the associated URN namespace. This document 111 additionally describes certain policy assumptions about how National 112 Libraries and their partner organizations partition, delegate, and 113 manage the namepace. Violation of those assumptions could impact the 114 utility of the NBN URN namespace. 116 URN:NBNs are in production use in several European countries 117 including (in alphabetical order) Austria, Finland, Germany, Hungary, 118 Italy, the Netherlands, Norway, Sweden, and Switzerland. The URN:NBN 119 namespace is collectively managed by these national libraries. URN: 120 NBNs have been applied to diverse content including Web archives, 121 digitized materials, research data, and doctoral dissertations. They 122 can be used by the national libraries and organizations co-operating 123 with them. 125 As a part of the initial development of the URN system in the late 126 1990s, the IETF URN working group agreed that it was important to 127 demonstrate that the URN syntax can accommodate existing identifier 128 systems. RFC 2288 [RFC2288] investigated the feasibility of using 129 ISBN, ISSN, and SICI (for further discussion of how these systems 130 have evolved as URNs, see the discussion in RFC 8254 [RFC8254]) as 131 URNs, with positive results; however, it did not formally register 132 corresponding URN namespaces. This was in part due to the still 133 evolving process to formalize criteria for namespace definition 134 documents and registration, consolidated later in the IETF, first 135 into RFC 2611 [RFC2611], then into RFC 3406 [RFC3406], and now given 136 by RFC 8141 [RFC8141]. 138 URN Namespaces have been registered for NBN (National Bibliography 139 Number), ISBN (International Standard Book Number), and ISSN 140 (International Serial Standard Number) in RFCs 3188 [RFC3188], 3187 141 [RFC3187], and 3044 [RFC3044], respectively. ISBN and ISSN 142 namespaces were made compliant with RFC 8141 [RFC8141] in 2017 by 143 publishing revised ISSN [ISSN-namespace] and ISBN [ISBN-namespace] 144 namespace registrations. 146 The term "National Bibliography Number" encompasses persistent local 147 identifier systems that the national libraries and their partner 148 organizations use in addition to the more formally (and 149 internationally) established identifiers. These partner 150 organizations include universities and their libraries and other 151 subsidiaries, other research institutions, plus governmental and 152 public organizations. Some national libraries maintain a significant 153 number of these liaison relationships; for instance, the German 154 National Library had almost 400 by early 2018 [NBN-Resolving]. 156 In practice, NBN differs from standard identifier systems such as 157 ISBN and ISSN because it is not a single identifier system with 158 standard-specified scope and syntax. Each NBN implementer creates 159 its own system with its own syntax and assignment rules. Each user 160 organization is also obliged to keep track of how NBNs are being 161 used; however, within the generic framework set in this document, 162 local NBN assignment policies may vary considerably. 164 Historically, NBNs have been applied in the national bibliographies 165 to identify the resources catalogued into them. Prior to the 166 emergence of bibliographic standard identifiers in the early 1970s, 167 national libraries assigned NBNs to all catalogued publications. 169 Since the late 1990s, the NBN scope has been extended to cover a vast 170 range of resources, both originally digital and digitized. Only a 171 small subset of these resources is cataloged in the national 172 bibliographies or other bibliographic databases. Digitized resources 173 and their component parts (such as still images in books or journal 174 articles) are examples of resources that may get NBNs. 176 It is possible to extend the scope of the NBN much further. The 177 National Library of Finland is using them in the Finnish National 178 Ontology Service Finto to identify corporate names (see 179 http://finto.fi/cn/en/). Using NBNs to identify metadata elements 180 provides a stable basis for creation of linked data. 182 Simple guidelines for using NBNs as URNs and the original namespace 183 registration were published in RFC 3188 [RFC3188]. The RFC at hand 184 replaces RFC 3188; sections discussing the methods by which URN:NBNs 185 should be resolved have been updated, unused features have been 186 eliminated, and the text is compliant with the stipulations of the 187 revised URN specification [RFC8141]. 189 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 190 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 191 document are to be interpreted as described in RFC 2119 [RFC2119]. 193 1.1. Discussion list 195 Comments are welcome and should be directed to the urn@ietf.org 196 mailing list or to the author. 198 [[CREF1: RFC-Editor: this subsection to be deleted before RFC 199 publication.]] 201 2. Conventions used in this document 203 "NBN" refers to any National Bibliography Number identifier system 204 used by the national libraries (or equivalent organizations) and 205 other institutions, which use these identifiers with national 206 libraries' support and permission. 208 In this memo, "URN:NBN" is used as a shorthand for "NBN-based URN". 210 3. Fundamental Namespace and Community Considerations for NBN 212 3.1. The URN:NBN Namespace 214 NBNs are widely used to identify both hand-held and digital resources 215 in the collections of national libraries and other institutions that 216 are responsible for preserving the cultural heritage of their 217 constituents. Resources in these collections are usually preserved 218 for a long time (i.e., for centuries). While the preferred methods 219 for digital preservation may vary over time and depend on the 220 content, the favorite one has been migration. Whenever necessary, a 221 resource in outdated file format is migrated into a more modern file 222 format. To the extent possible, all old versions of the resource are 223 also kept, in order to alleviate the negative effects of partially 224 successful migrations and gradual loss of original look and feel that 225 may accompany even fully successful migrations. When NBN is used to 226 identify manifestations and there are many of them for a single work, 227 local policy can require that each manifestation ought to have its 228 own NBN. 230 NBNs are typically used to identify objects for which standard 231 identifiers such as ISBN are not applicable. However, NBNs can be 232 used for component resources even when the resource as a whole 233 qualifies for a standard identifier. For instance, if a digitized 234 book has an ISBN, JPEG image files of its pages might be assigned 235 NBNs. These URN:NBNs can be used as persistent links to the pages. 237 The scope of standard identifier systems such as ISBN and ISSN is 238 limited; they are applicable only to certain kinds of resources. One 239 of the roles of the NBN is to fill in the gaps left by the standard 240 identifiers. Collectively, these identifiers and NBNs cover all 241 resources the national libraries and their partners need to include 242 in their collections. 244 Section 4 below, and particularly Section 4.1, present a more 245 detailed overview of the structure of the NBN namespace, related 246 institutions, and the identifier assignment principles used. 248 3.2. Community Considerations for NBNs 250 National libraries are the key organizations providing persistent URN 251 resolution services for resources identified with NBNs, independent 252 of their form. As co-ordinators of NBN usage, national libraries 253 have allowed other organizations such as university libraries or 254 governmental organizations to assign NBNs to the resources these 255 organizations preserve for the long term. In such case, the national 256 library co-ordinates the use of NBNs at the national level. National 257 libraries can also provide URN resolution services and technical 258 services to other NBN users. These organizations are expected to 259 either establish their own URN resolution services or use the 260 technical infrastructure provided by the national library. URN:NBNs 261 are expected to be resolvable and support one or more resolution 262 services. 264 Although NBNs can be used to identify component resources, the NBN 265 Namespace does not specify a generic, intrinsic syntax for doing 266 that. However, there are at least two different ways in which 267 component resources can be taken into account within the NBN 268 namespace. 270 The simplest and probably the most common approach is to assign a 271 separate NBN for each component resource such as a file containing a 272 digitized page of a book, and make no provisions to make such NBNs 273 discernible in a systematical way from others. 275 Second, if the stipulations of the URI Generic Syntax [RFC3986] and 276 the Internet media type specification [RFC2046] are met, in 277 accordance with the provisions in RFC 8141, the URN f-component can 278 be attached to URN:NBNs in order to indicate the desired location 279 within the resource supplied by URN resolution. 281 From the library community point of view it is important that the 282 f-component is not a part of the NSS and therefore f-component 283 attachment does not mean that the relevant component part is 284 identified. Moreover, the resolution process still retrieves the 285 entire resource even if there is an f-component. The component part 286 selection is applied by the resolution client (e.g., browser) to the 287 resource returned by the resolution process. In other words, in this 288 latter case the component parts are just logical and physical parts 289 of the identified resource whereas in the former cases they are 290 independently named entities. 292 Resources identified by NBNs are not always available in the 293 Internet. If one is not, the URN:NBN can resolve to a surrogate such 294 as a metadata record describing the identified resource. 296 Section 4 below, and particularly its Section 4.4, presents a 297 detailed overview of the application of the URN:NBN Namespace as well 298 as the principles of, and systems used for, the resolution of NBN- 299 based URNs. 301 4. National Bibliography Number URNs 303 4.1. Assignment 305 National Bibliography Number (NBN) is a generic term referring to a 306 group of identifier systems administered by national libraries and 307 institutions authorized by them. The NBN assignment is typically 308 performed by the organization hosting the resource. National 309 libraries are committed to permanent preservation of their deposit 310 collections. 312 Assignment of NBN-based URNs is controlled on national level by the 313 national library (or national libraries, if there is more than one). 314 National guidelines can differ, but the identified resources 315 themselves are usually persistent. 317 Different national URN:NBN assignment policies have resulted in 318 varying levels of control of the assignment process. Manual URN:NBN 319 assignment by the library personnel provides the tightest control, 320 especially if the URN:NBNs cover only resources catalogued into the 321 national bibliography. In most national libraries, the scope of 322 URN:NBN is already much broader than this. Usage rules can vary 323 within one country, from one URN:NBN sub-namespace to the next. 325 Each national library uses NBNs independently of other national 326 libraries; apart from this document, there are no guidelines which 327 specify or control NBN usage. NBNs as such are unique only on the 328 national level. When used as URNs, base NBN strings MUST be 329 augmented with a controlled prefix, which is the particular nation's 330 ISO 3166-1 alpha-2 two-letter country code (referred to as "ISO 331 country code" below) [ISO3166-1]. These prefixes guarantee 332 uniqueness of the URN:NBNs at the global scale [Iso3166MA]. 334 National libraries using URN:NBNs usually specify local assignment 335 policies for themselves. Such policy can limit the URN:NBN usage to 336 e.g. the resources stored in the national library's digital 337 collections or databases. Athough this specification does not 338 specify principles for URN:NBN assignment policies that can be 339 applied, NBNs assigned to short-lived resources should not be made 340 URN:NBNs unless such policy can be justified. 342 URN:NBN assignment policy can clarify for instance the local policy 343 concerning identifier assignment to component parts of resources, and 344 specify with sufficient detail the syntax of local component 345 identifiers (if there is one as a discernible part of the NBNs). The 346 policy can also cover any employed extensions to the default NBN 347 scope. 349 NBNs as such are locally but not globally unique; two national 350 libraries can assign the same NBN to different resources. A prefix, 351 based on the ISO country code as described above, guarantees the 352 global uniqueness of URN:NBNs. An NBN, once it has been assigned to 353 a resource, MUST be persistent, and therefore URN:NBNs are persistent 354 as well. 356 A URN:NBN, once it has been generated from a NBN, MUST NOT be re- 357 used for another resource. 359 Users of the URN:NBN namespace MUST ensure that they do not assign 360 the same URN:NBN twice. Different policies can be applied to 361 guarantee this. For instance, NBNs and corresponding URN:NBNs can be 362 assigned sequentially by programs in order to avoid human mistakes. 363 It is also possible to use printable representations of checksums 364 such as SHA-1 [RFC6234] as NBNs. 366 4.2. Syntax 368 The namespace-specific string (NSS) will consist of three parts: 370 o a prefix, consisting of an ISO 3166-1 alpha-2 country code and 371 optional sub-namespace code(s) separated by colon(s), 373 o a hyphen (-) as the delimiting character, and 375 o an NBN string assigned by the national library or sub-delegated 376 authority. 378 The following formal definition uses ABNF [RFC5234]. 380 nbn_nss = prefix "-" nbn_string 382 prefix = iso_cc *( ":" subspc ) 383 ; the entire prefix is case-insensitive 385 iso_cc = 2ALPHA 386 ; alpha-2 country code as assigned by ISO 3166, part 1 387 ; (identifies the national library to which the branch 388 ; is delegated) 390 subspc = 1*(ALPHA / DIGIT) 391 ; as assigned by the respective national library 393 nbn_string = path-rootless 394 ; the "path-rootless" rule is defined in RFC 3986. 395 ; syntax requirements specified in RFC 8141 MUST be 396 ; taken into account. 398 Colon SHOULD be used within the prefix only as a delimiting character 399 between the ISO 3166-1 country code and sub-namespace code(s), which 400 split the national namespace into smaller parts. 402 The structure (if any) of the nbn_string is determined by the 403 authority for the prefix. Whereas the prefix is regarded as case- 404 insensitive, NBN strings can be case-sensitive at the preference of 405 the assigning authority; parsers therefore MUST treat these as case- 406 sensitive; any case mapping needed to introduce case-insensitivity is 407 the responsibility of the relevant resolution system. 409 Hyphen SHOULD be used as the delimiting character between the prefix 410 and the NBN string. Within the NBN string, hyphen MAY be used for 411 separating different sections of the identifier from one another. 413 All two-letter codes are reserved by the ISO 3166 Maintenance Agency 414 for either existing and possible future ISO country codes (or for 415 private use). 417 Sub-namespace identifiers MUST be registered on the national level by 418 the national library that assigned the identifier. The list of such 419 identifiers can be made publicly available via the Web. 421 Note: Because case mapping for ASCII letters is completely reversible 422 and does not lose information, the case used in case-insensitive 423 matching is a local matter; implementations can convert to lower or 424 upper case as they see fit; they only need to do it consistently. 426 4.2.1. Usage of r-component and q-component 428 URN:NBN resolvers do not currently support the use of either 429 r-component or q-component. 431 Resolution services based on r-component can be implemented in the 432 future when the r-component syntax and semantics has been specified. 434 4.2.2. Usage of f-component 436 If URN:NBN resolves to the identified resource and the media type of 437 the resource supports f-component usage, it can be used to indicate a 438 location within the identified resource. Persistence is achieved if 439 the URN:NBN is assigned to one and only one version of a resource, 440 such as PDF/A version of a book. 442 The URN:NBN Namespace does not impose any restrictions of its own on 443 f-component usage. 445 4.3. Encoding Considerations and Lexical Equivalence 447 Expressing NBNs as URNs is usually straightforward, as normally only 448 ASCII characters are used in NBN strings. If this is not the case, 449 non-ASCII characters in NBNs MUST be translated into canonical form 450 as specified in RFC 8141. If a national library uses NBNs that can 451 contain percent-encoded characters higher than U+007F, the library 452 needs to carefully define the canonical transformation from theseNBNs 453 into URNs, including normalization forms. 455 When an NBN is used as a URN, the namespace-specific string (NSS) 456 MUST consist of three parts: 458 o a prefix, structured as a primary prefix, which is a two-letter 459 ISO 3166-1 country code of the library's country, and zero or more 460 secondary prefixes, each indicated by a delimiting colon character 461 (:) and a sub-namespace identifier, 463 o a hyphen (-) as a delimiting character, and 465 o the NBN string. 467 Different delimiting characters are not semantically equivalent. 469 The syntax and roles of the three parts listed above are described in 470 Section 4.2. 472 If there are several national libraries in one country, these 473 libraries MUST agree on how to divide the national namespace between 474 themselves using this method before the URN:NBN assignment begins in 475 any of these libraries. 477 A national library MAY also assign URN:NBN sub-namespaces to trusted 478 organizations such as universities or government institutions. The 479 sub-namespace MAY be further divided by the partner organization. 480 All sub-namespace identifiers used within a country-code-based 481 namespace MUST be registered on the national level by the national 482 library that assigned the code. The national register of these codes 483 SHOULD be made available online. 485 Being part of the prefix, sub-namespace identifier strings are case- 486 insensitive. They MUST NOT contain any colons or hyphens. 488 Formally, two URN:NBNs are lexically equivalent if they are octet- 489 by-octet equal after the following (conceptional) preprocessing: 491 1. convert all characters in the leading "urn:nbn:" token to a 492 single case; 494 2. convert all characters in the prefix (country code and its 495 optional sub-divisions) to a single case; 497 3. convert all characters embedded in any percent-encodings to a 498 single case; 500 Models (indicated linebreak inserted for readability): 502 URN:NBN:- 504 URN:NBN::-\ 505 507 Examples: 509 URN:NBN:fi-fe201003181510 511 urn:nbn:ch:bel-9039 513 urn:nbn:se:uu:diva-3475 515 urn:nbn:hu-3006 517 4.4. Resolution and Persistence of NBN-based URNs 519 Eventually, URNs might be resolved with the help of a global resolver 520 discovery service (GRDS), and URN:NBN syntax makes it possible to 521 locate the relevant resolver. Since no GRDS system has been 522 installed yet in the Internet, URN:NBNs are embedded in HTTP URIs in 523 order to make them actionable in the present Internet. In these HTTP 524 URIs, the authority part must point to the appropriate URN resolution 525 service. For instance, in Finland, the address of the national URN 526 resolver is . Thus the HTTP URI for the Finnish URN 527 in the example above is . 529 The country code-based prefix part of the URN:NBN namespace-specific 530 string will provide a hint needed to find the correct resolution 531 service for URN:NBNs from the GRDS when it is established. 533 There are three inter-related aspects of persistence that need to be 534 discussed: persistence of the objects itself, persistence of the 535 identifier, and persistence of the URN resolvers. 537 NBNs have traditionally been assigned to printed resources, which 538 tend to be persistent. In contrast, digital resources require 539 frequent migrations to guarantee accessibility. Although it is 540 impossible to estimate how often migrations are needed, hardware and 541 software upgrades take place frequently, and a life time exceeding 542 10-20 years can be considered as long. 544 However, it is a common practice to keep also the original and 545 previously migrated versions of resources. Therefore even outdated 546 versions of resources can be available in digital archives, no matter 547 how old or difficult to use they have become. 549 If all versions of a resource are kept, a user who requires 550 authenticity can retrieve the original version of the resource, 551 whereas a user to whom the ease of use is a priority is likely to be 552 satisfied with the latest version. In order to enable the users to 553 find the best match, a national library can link all manifestations 554 of a resource to each other so as to make a user aware of them. 556 Thus, even if specific versions of digital resources are not normally 557 persistent, persistent identifiers such as URN:NBNs support 558 information architectures that enable persistent access to any 559 version of the resource, including ones which can only be utilized by 560 using digital archeology tools such as custom made applications to 561 render the resource. 563 Persistence of URN resolvers themselves is mainly an organizational 564 issue, related to the persistence of organizations maintaining them. 565 As URN:NBN resolution services will be supplied (primarily) by the 566 national libraries, these services are likely to be long-lived. 568 4.5. Additional considerations 570 It is a good idea to apply URN:NBNs (or other persistent identifiers) 571 to all resources that have been prioritized in the organization's 572 digital preservation plan. 574 Assignment of URN:NBNs to resources that are known to not be 575 persistent should be considered carefully. URN:NBNs can however be 576 applied to resources that have a low-level preservation priority and 577 will not be migrated to more modern file formats or preserved via 578 emulation. 580 If the identified version of a resource has disappeared, the 581 resolution process can supply a surrogate if one exists. A surrogate 582 can be for instance a more modern digital version of the original 583 electronic resource. 585 5. URN Namespace ID (NID) Registration for the National Bibliography 586 Number (NBN) 588 This URN Namespace registration describes how National Bibliography 589 Numbers (NBNs) can be supported within the URN framework; it uses the 590 updated IANA template specified in RFC 8141. 592 Namespace Indentifier: NBN 593 This Namespace ID was formally assigned to the National 594 Bibliography Number in October 2001 when the namespace was 595 registered officially [RFC3188]. Utilization of URN:NBNs had 596 started in demo systems already in 1998. Since 2001, tens of 597 millions of URN:NBNs have been assigned. The number of users of 598 the namespace has grown in two ways: new national libraries have 599 started using NBNs, and many national libraries using the system 600 have formed new liaisons. 602 Version: 4 604 Date: 2018-04-09 606 Registrant: 607 Name: Juha Hakala 608 Affiliation: Senior Adviser, The National Library of Finland 609 Email: juha.hakala@helsinki.fi 610 Postal: P.O.Box 15, 00014 Helsinki University, Finland 611 Web URL: http://www.nationallibrary.fi/ 613 The National Library of Finland registered the namespace on behalf 614 of the Conference of the European National Librarians (CENL) and 615 Conference of Directors of National Libraries (CDNL). The NBN 616 namespace is available for free for the national libraries. They 617 can allow other organizations to assign URN:NBNs and use the 618 resolution services established by the library for free or for a 619 fee. The fees, if collected, can be based on, e.g., the 620 maintenance costs of the system. 622 Purpose: See Section 3 of RFC XXXX 624 Syntax: See Section 4.2 of RFC XXXX 626 Assignment: See Section 4.1 of RFC XXXX 628 Security and Privacy: See Section 7 of RFC XXXX 630 Interoperability: 631 National libraries and their partners usually apply URN:NBNs if a 632 standard identifier such as ISBN is not applicable for the 633 resource to be identified. Some overlap with other URN namespaces 634 is possible. 636 URN:NBNs may contain characters which must be percent-encoded, but 637 usually they consist of printable ASCII characters only. 639 Resolution: See Section 4.4 of RFC XXXX 641 Documentation: RFC XXXX 643 Revision Information: 644 This version of the URN:NBN namespace registration has beens 645 updated to use the revised definition of URN syntax from RFC 8141, 646 although usage of r-components is not specified yet. In addition, 647 non-ISO 3166 (country code) based NBNs have been deleted due to 648 lack of deployment. The entire NBN prefix is now specified to be 649 case-insensitive in accordance with established practice. This 650 version also includes numerous clarifications based on actial 651 usage of UR:NBNs. 653 6. IANA Considerations 655 IANA is asked to update the existing registration of the Formal URN 656 Namespace 'NBN' using the template given above in Section 5. 658 7. Security Considerations 660 This document defines means of encoding NBNs as URNs. A URN 661 resolution service for NBN-based URNs is depicted, but only at a 662 generic level; thus, questions of secure or authenticated resolution 663 mechanisms and authentication of users are out of scope of this 664 document. 666 Although no validation mechanisms are specified on the global level 667 (beyond a routine check of those characters that require special 668 encoding when employed in URIs), NBNs assigned by any given authority 669 can have a well-specified and rich syntax (including, e.g., fixed 670 length and checksum). In such cases, it is possible to validate the 671 correctness of NBNs programmatically. 673 Issues regarding intellectual property rights associated with objects 674 identified by the URN:NBNs are beyond the scope of this document, as 675 are questions about rights to the databases that might be used to 676 construct resolution services. 678 Beyond the generic security considerations laid out in the underlying 679 documents listed in the Normative References (Section 10.1), no 680 specific security threats have been identified for NBN-based URNs. 682 8. Acknowledgements 684 Revision of RFC 3188 started during the project PersID. [PERSID] 685 Later the revision was included in the charter of the URNbis working 686 group and worked on in that group in parallel with what became RFC 687 8141 and RFC 8254. The author wishes to thank his colleagues in the 688 PersID project and the URNbis participants for their support and 689 review comments. 691 Tommi Jauhiainen has provided feedback on an early version of this 692 draft. The author wishes to thank Tommi Jauhiainen, Bengt Neiss, and 693 Lars Svensson for the comments they have provided to various versions 694 of this draft. 696 John Klensin provided significant editorial and advisory support for 697 later versions of the draft. 699 9. Contributors 701 This document would not have been possible without contributions by 702 Alfred Hoenes. 704 10. References 706 10.1. Normative References 708 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 709 Requirement Levels", BCP 14, RFC 2119, 710 DOI 10.17487/RFC2119, March 1997, 711 . 713 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 714 Resource Identifier (URI): Generic Syntax", STD 66, 715 RFC 3986, DOI 10.17487/RFC3986, January 2005, 716 . 718 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 719 Specifications: ABNF", STD 68, RFC 5234, 720 DOI 10.17487/RFC5234, January 2008, 721 . 723 [RFC8141] Saint-Andre, P. and J. Klensin, "Uniform Resource Names 724 (URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017, 725 . 727 10.2. Informative References 729 [IANA-URI] 730 IANA, "URI Schemes Registry", 731 . 733 [IANA-URN] 734 IANA, "URN Namespace Registry", 735 . 737 [ISBN-namespace] 738 Griffiths, S., "Namespace Registration for International 739 Standard Book Number (ISBN) ISO 2108:2017", 740 . 742 [ISO3166-1] 743 ISO, "Codes for the representation of names of countries 744 and their subdivisions -- Part 1: Country codes", 745 ISO 3166-1:2013, 2013, 746 . 748 [Iso3166MA] 749 ISO, "ISO Maintenance agency for ISO 3166 country codes", 750 2006, . 752 [ISSN-namespace] 753 Bequet, G., "Namespace Registration for International 754 Standard Serial Number (ISSN) and Linking ISSN (ISSN-L) 755 based on ISO 3297:2007", 756 . 758 [NBN-Resolving] 759 Deutsche Nationalbibliothek, "URN:NBN Resolver fuer 760 Deutschland und Schweiz: Information ueber Partner 761 Institutionen", Captured 2018-04-09, 762 . 764 [PERSID] PersID initiative, 2009-2011, "persid: Building a 765 persistent identifier infrastructure", 766 Captured 2018-04-09, . 768 [RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, 769 DOI 10.17487/RFC1321, April 1992, 770 . 772 [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail 773 Extensions (MIME) Part Two: Media Types", RFC 2046, 774 DOI 10.17487/RFC2046, November 1996, 775 . 777 [RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141, 778 May 1997, . 780 [RFC2288] Lynch, C., Preston, C., and R. Daniel, "Using Existing 781 Bibliographic Identifiers as Uniform Resource Names", 782 RFC 2288, DOI 10.17487/RFC2288, February 1998, 783 . 785 [RFC2611] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, 786 "URN Namespace Definition Mechanisms", BCP 33, RFC 2611, 787 DOI 10.17487/RFC2611, June 1999, 788 . 790 [RFC3044] Rozenfeld, S., "Using The ISSN (International Serial 791 Standard Number) as URN (Uniform Resource Names) within an 792 ISSN-URN Namespace", RFC 3044, DOI 10.17487/RFC3044, 793 January 2001, . 795 [RFC3187] Hakala, J. and H. Walravens, "Using International Standard 796 Book Numbers as Uniform Resource Names", RFC 3187, 797 DOI 10.17487/RFC3187, October 2001, 798 . 800 [RFC3188] Hakala, J., "Using National Bibliography Numbers as 801 Uniform Resource Names", RFC 3188, DOI 10.17487/RFC3188, 802 October 2001, . 804 [RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, 805 "Uniform Resource Names (URN) Namespace Definition 806 Mechanisms", RFC 3406, DOI 10.17487/RFC3406, October 2002, 807 . 809 [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms 810 (SHA and SHA-based HMAC and HKDF)", RFC 6234, 811 DOI 10.17487/RFC6234, May 2011, 812 . 814 [RFC8254] Klensin, J. and J. Hakala, "Uniform Resource Name (URN) 815 Namespace Registration Transition", RFC 8254, 816 DOI 10.17487/RFC8254, October 2017, 817 . 819 Appendix A. Significant Changes from RFC 3188 821 Numerous clarifications based on a decade of experience with RFC 822 3188. 824 Non-ISO 3166 (country code) based NBNs have been removed due to lack 825 of usage. 827 In accordance with established practice, the whole NBN prefix is now 828 declared case-insensitive. 830 The document is based on the new URN Syntax specification, RFC 8141. 832 Use of query components and fragment components with this Namespace 833 is now specified, in accordance with RFC 8141. 835 Appendix B. Change Log 837 [[CREF2: RFC-Editor: Please delete this whole section before RFC 838 publication.]] 840 B.1. draft-hakala-rfc3188bis-nbn-urn-00 to draft-ietf-urnbis-*-00 842 o formal updates for a WG draft; no more "Updates: 2288"; 844 o introduced references to other URNbis WG documents; 846 o changes based on review by Tommi Jauhiainen; 847 o Sect. 3 restructured into namespace and community considerations; 849 o old Sect. 7 incorporated in new Sect. 3.1; 851 o Security Considerations: old Section 4.5 merged into Section 5; 853 o added guidelines for when two manifestations of the same work 854 should get different URN:NBNs; 856 o clarified role of ISO 3166/MA for ISO 3166-1 country codes; 858 o clarified role of non-ISO prefix registry maintaind by the LoC; 860 o resolved inconsistency in lexical equivalence rules: as already 861 specified for ISO alpha-2 country-codes, and in accordance with 862 established practice, the whole NBN prefix is now declared case- 863 insensitive; 865 o registration template adapted to rfc3406bis[-00]; 867 o numerous editorial fixes and enhancements. 869 B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01 871 o Numerous changes to accommodate the outcome of the discussions on 872 the urn list; 874 o three different ways of identifying fragments specified; 876 o removed some redundant/irrelevant paragraphs/subsections; 878 o the "one manifestation, one URN" principle strenghtened; 880 o introduced the idea of interlinking manifestations; 882 o extended the scope of the NBN explicitly to works; 884 o added reference to S4.2 in namespace registration; 886 o numerous editorial fixes and enhancements. 888 B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02 890 o Removed the possibility of using prefixes not based on country 891 codes; 893 o replaced all instances of the word object with resources; 894 o removed some redundant/irrelevant paragraphs/subsections; 896 o allowed the possibility for identifying data elements with NBNs; 898 o a few editorial fixes and enhancements. 900 B.4. draft-ietf-urnbis-rfc3188bis-nbn-urn-02 to -03 902 o improved text related to "prefix" in NSS; 904 o addressed issues with text related to case-sensitivity of NSS 905 strings; 907 o addressed comments and open details on requirements language; 909 o switched language to talk about "resource" instead of "object"; 911 o several more editorial fixes and enhancements. 913 B.5. draft-ietf-urnbis-rfc3188bis-nbn-urn-03 to -04 915 o specification of how to use URN query and fragment part based on 916 the revised versions of rfc2141bis and rfc3406bis; 918 o various textual improvements and clarifications, including: 920 o textual alignments with rfc3187bis draft vers. -03; 922 o multiple editorial fixes and improvements. 924 B.6. draft-ietf-urnbis-rfc3188bis-nbn-urn-04 (2012-10-22) to draft- 925 hakala-urn-nbn-rfc3188bis-00 927 o Conversion of document to XML2RFC format, change of name (not a WG 928 task). 930 o Adjusted for changes to 2141bis, consolidation of RFC 3406bis, 931 creation of transition document. 933 o Made a number of changes to reflect publication of RFC 8141 934 (previously 2141bis and 3406bis) and update terminology, 935 references, and current status to early 2018. 937 B.7. draft-hakala-urn-nbn-rfc3188bis-00 (2018-06-02) to draft-hakala- 938 urn-nbn-rfc3188bis-01 940 o Adjusted on the basis of feedback from IESG. 942 o Theoretical discussion on the usage of r- and q-components has 943 been deleted. 945 o Out-of-date sections of the text have been updated. 947 Author's Address 949 Juha Hakala 950 The National Library of Finland 951 P.O. Box 15, Helsinki University 952 Helsinki, MA FIN-00014 953 Finland 955 Email: juha.hakala@helsinki.fi