idnits 2.17.1 draft-ietf-urnbis-rfc3188bis-nbn-urn-04.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). -- The document date (October 22, 2012) is 4176 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: '-00' is mentioned on line 889, but not defined == Outdated reference: A later version (-22) exists of draft-ietf-urnbis-rfc2141bis-urn-03 == Outdated reference: A later version (-09) exists of draft-ietf-urnbis-rfc3406bis-urn-ns-reg-03 -- Possible downref: Normative reference to a draft: ref. 'I-D.ietf-urnbis-rfc3406bis-urn-ns-reg' -- 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 3188 (Obsoleted by RFC 8458) -- Obsolete informational reference (is this intentional?): RFC 3406 (Obsoleted by RFC 8141) Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 8 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IETF URNbis WG J. Hakala 3 Internet-Draft The National Library of Finland 4 Obsoletes: 3188 (if approved) A. Hoenes, Ed. 5 Intended status: Standards Track TR-Sys 6 Expires: April 25, 2013 October 22, 2012 8 Using National Bibliography Numbers as Uniform Resource Names 9 draft-ietf-urnbis-rfc3188bis-nbn-urn-04 11 Abstract 13 National Bibliography Numbers, NBNs, are used by the national 14 libraries and other organizations in order to identify various 15 resources such as digitized monographs. Generally, NBNs are applied 16 to resources that do not have an established (standard) identifier 17 system of their own. 19 A URN (Uniform Resource Names) namespace for NBNs was established in 20 2001 in RFC 3188. Since then, several European national libraries 21 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 the RFC 3406bis draft is included. 27 Discussion 29 Comments are welcome and should be directed to the urn@ietf.org 30 mailing list or the authors. 31 [[ RFC-Editor: this clause to be deleted before RFC publication ]] 33 Status of This Memo 35 This Internet-Draft is submitted in full conformance with the 36 provisions of BCP 78 and BCP 79. 38 Internet-Drafts are working documents of the Internet Engineering 39 Task Force (IETF). Note that other groups may also distribute 40 working documents as Internet-Drafts. The list of current Internet- 41 Drafts is at http://datatracker.ietf.org/drafts/current/. 43 Internet-Drafts are draft documents valid for a maximum of six months 44 and may be updated, replaced, or obsoleted by other documents at any 45 time. It is inappropriate to use Internet-Drafts as reference 46 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on April 25, 2013. 50 Copyright Notice 52 Copyright (c) 2012 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (http://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 68 2. Conventions used in this document . . . . . . . . . . . . . . 4 69 3. Fundamental Namespace and Community Considerations for NBN . . 5 70 3.1. The URN:NBN Namespace . . . . . . . . . . . . . . . . . . 5 71 3.2. Community Considerations for NBNs . . . . . . . . . . . . 5 72 4. National Bibliography Numbers (NBNs) . . . . . . . . . . . . . 7 73 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 7 74 4.2. Encoding Considerations and Lexical Equivalence . . . . . 8 75 4.3. Resolution and Persistence of NBN-based URNs . . . . . . . 9 76 4.4. Additional Considerations . . . . . . . . . . . . . . . . 10 77 5. URN Namespace ID Registration for the National 78 Bibliography Number (NBN) . . . . . . . . . . . . . . . . . . 11 79 6. Security Considerations . . . . . . . . . . . . . . . . . . . 16 80 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 81 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 82 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 83 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17 84 9.2. Informative References . . . . . . . . . . . . . . . . . . 17 85 Appendix A. Significant Changes from RFC 3188 . . . . . . . . . . 18 86 Appendix B. Draft Change Log . . . . . . . . . . . . . . . . . . 19 87 B.1. draft-hakala-rfc3188bis-nbn-urn-00 to 88 draft-ietf-urnbis-*-00 . . . . . . . . . . . . . . . . . . 19 89 B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01 . . . . . . 19 90 B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02 . . . . . . 19 91 B.4. draft-ietf-urnbis-rfc3188bis-nbn-urn-02 to -03 . . . . . . 20 92 B.5. draft-ietf-urnbis-rfc3188bis-nbn-urn-03 to -04 . . . . . . 20 94 1. Introduction 96 One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986], 97 [IANA-URI]) is 'URN' (Uniform Resource Name) as originally defined in 98 RFC 2141 [RFC2141] and now being formally specified in RFC 2141bis 99 [I-D.ietf-urnbis-rfc2141bis-urn]. Any traditional identifier, when 100 used within the URN system, needs to have a namespace of its own. At 101 the time of this writing, there were 46 registered Formal URN 102 namespaces (see [IANA-URN]), one of which belongs to NBN, National 103 Bibliography Number, as specified 2001 in RFC 3188 [RFC3188]. 105 URN:NBNs are in production use in several European countries 106 including (in alphabetical order) Austria, Finland, Germany, Italy, 107 the Netherlands, Norway, Sweden, and Switzerland; other countries in 108 Europe and elsewhere are considering usage of them. The URN:NBN 109 namespace is collectively managed by the national libraries. URN: 110 NBNs have been applied to diverse content including Web archives, 111 digitized materials, research data, and doctoral dissertations. They 112 can be used by the national libraries and organizations co-operating 113 with them. 115 As a part of the initial development of the URN system back in the 116 late 1990s, the IETF URN working group agreed that it was important 117 to demonstrate that the URN syntax can accommodate existing 118 identifier systems. RFC 2288 [RFC2288] investigated the feasibility 119 of using three identifiers (ISBN, ISSN and SICI -- see below) as 120 URNs, with positive results; however, it did not formally register 121 corresponding URN namespaces. This was in part due to the still 122 evolving process to formalize criteria for namespace definition 123 documents and registration, consolidated later in the IETF, first 124 into RFC 2611 [RFC2611], then into RFC 3406 [RFC3406], and now given 125 by RFC 3406bis [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]. 127 URN Namespaces have subsequently been registered for NBN (National 128 Bibliography Number), ISBN (International Standard Book Number), and 129 ISSN (International Serial Standard Number) in RFCs 3188 [RFC3188], 130 3187 [RFC3187], and 3044 [RFC3044], respectively. The ISBN namespace 131 registration has now been revised so that it covers both ISBN-10 and 132 ISBN-13 [I-D.ietf-urnbis-rfc3187bis-isbn-urn]. Since the current 133 ISSN registration does not cover ISSN-L, defined in the new version 134 of the ISSN standard, an update of the existing namespace 135 registration is also pursued currently RFC 3044 [RFC3044], 137 The term "National Bibliography Number" encompasses persistent local 138 identifier systems that the national libraries and their partner 139 organizations use in addition to the more formally (and 140 internationally) established identifiers. In practice, NBN differs 141 from the standard identifier systems listed above because it is not a 142 single identifier system with standard-specified scope and syntax. 143 Each NBN implementer is obliged to keep track of how NBNs are being 144 used, but within the generic framework set in this document, local 145 NBN assignment policies may vary a lot. 147 Historically, NBNs were only applied in the national bibliographies 148 to identify the resources catalogued into it. Prior to the emergence 149 of bibliographic standard identifiers, every publication got an NBN. 150 As of this writing, NBNs are given to, e.g., new books that do not 151 have an ISBN. 153 During the last 10 years, the NBN scope has been extended to cover a 154 vast range of digitized and born digital resources available in the 155 Internet. Only a small subset of these resources is catalogued in 156 the national bibliographies or other bibliographic databases. Web 157 contents harvested into Web archives are an example of resources that 158 are usually not catalogued but can nevertheless receive an NBN. 160 It is possible and even likely that the scope of the NBN will be 161 expanded even further. For instance, NBNs can be used to identify 162 metadata elements in order to facilitate creation of linked data. 163 NBNs can also be used for identification of (immaterial) works when 164 there is no standard identifier that could be used for the type of 165 work in question. Still images are an example of this. 167 Simple guidelines for using NBNs as URNs and the original namespace 168 registration were published in RFC 3188 [RFC3188]. The RFC at hand 169 replaces RFC 3188; sections discussing the methods in which URN:NBNs 170 should be resolved have been updated, unused features have been 171 eliminated, and the text is compliant with the stipulations of the 172 revised URN specification and URN Namespace definition documents (RFC 173 2141bis [I-D.ietf-urnbis-rfc2141bis-urn], RFC 3406bis 174 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]). 176 2. Conventions used in this document 178 When spelled in all-capitals as in this paragraph, the key words 179 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", 180 "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document 181 are to be interpreted as described in BCP 14 [RFC2119]. 183 "NBN" refers to any National Bibliography Number identifier system 184 used by the national libraries and other institutions using these 185 identifiers with the national library's support and permission. 187 In this memo, "URN:NBN" is used as a shorthand for "NBN-based URN". 189 3. Fundamental Namespace and Community Considerations for NBN 191 3.1. The URN:NBN Namespace 193 NBNs are widely used to identify both hand-held and digital resources 194 in the deposit collections of national libraries and similar 195 institutions that are responsible for preserving the cultural 196 heritage of their constituents. All resources in these collections 197 will be preserved for long term. While the preferred methods for 198 digital preservation may vary over time and depending on the content, 199 the favourite one is currently migration. Whenever necessary, a 200 document in outdated file format is migrated into a more modern file 201 format. The old versions of a resource are kept, in order to 202 alleviate the negative effects of failed migrations and gradual loss 203 of original look and feel that often accompany even successful 204 migrations. When there are multiple manifestations of a digital 205 object, each one SHOULD have its own NBN. 207 NBNs SHOULD only be used for objects when standard identifiers such 208 as ISBN are not applicable. However, NBNs MAY be used for component 209 resources even when the resource as a whole qualifies for a standard 210 identifier. For instance, if a digitized book has an ISBN, a JPEG 211 file containing a single page of the book can get an NBN. Then the 212 URN:NBN can be used as a persistent link to the page. 214 The scope of standard identifier systems such as ISBN and ISSN is 215 limited; they are applicable only to certain kinds of resources. 216 Generally speaking, the role of the NBN is to fill in the gaps. 217 Collectively, the standard bibliographic identifiers and NBNs cover 218 -- at least in theory -- all resources the national libraries and 219 their partners need to preserve for long term. NBNs can also be 220 applied to immaterial works (which can have 0-n physical 221 manifestations, and each manifestation 0-n items) and, e.g., metadata 222 elements plus terms and concepts in ontologies and thesauri. 224 Section 4 below, and there in particular Section 4.1, presents a more 225 detailed overview of the structure of the NBN namespace, related 226 institutions, and the identifier assignment principles used. 228 3.2. Community Considerations for NBNs 230 National libraries are the key organizations providing persistent URN 231 resolution services for resources identified with NBNs, independent 232 of their form. National libraries MAY allow other organizations such 233 as university libraries or governmental organizations to assign NBNs 234 to the resources they preserve for long term. In such case, the 235 national library MUST co-ordinate the use of NBNs at the national 236 level. National libraries can also provide URN resolution services 237 and technical services to other NBN users. These organizations MUST 238 either establish their own URN resolution services or use the 239 technical infrastructure provided by the national library. In the 240 URN:NBN namespace, each persistent identifier should be resolvable 241 and provide one or more resolution services. 243 NBNs MAY be used to identify component resources, but the NBN 244 Namespace does not specify a generic, intrinsic syntax for doing 245 that. However, there are at least three different ways in which 246 component resources can be identified and used within the NBN 247 namespace. 249 The simplest approach is to assign a separate NBN for each component 250 resource such as a file containing a digitized page of a book, and 251 make no provisions to make such NBNs discernible in a systematical 252 way from others. The URN:NBN assigned to the component resource 253 enables direct and persistent access to the page, which might 254 otherwise be available only via browsing the book from the title page 255 to the page wanted. 257 Second, a local "fragment" syntax MAY be used to identify component 258 resources in a structured manner within the NSS, independently of the 259 requirements of RFC 3986. Such private fragment identifiers SHOULD 260 be recognized as such by the appropriate URN resolver application. 261 The resolver SHOULD be able to process the fragment part in the URN: 262 NBN correctly; if so, the result is the identified component part of 263 the resource. For instance, if the resource is a database table, the 264 identified component could be a single data element stored in the 265 table. 267 Finally, if the stipulations of the URI Generic Syntax (RFC 3986 268 [RFC3986]) and the Internet media type specification RFC 2046 269 [RFC2046] are met, in accordance with the provisions in RFC 2141bis 270 [I-D.ietf-urnbis-rfc2141bis-urn], URI fragment identifiers MAY be 271 attached to URI references to URN:NBNs in order to designate a 272 fragment of the media supplied by URN resolution. 274 Note that this implies that the fragment identifier is not a part of 275 the NSS, that the resolution process SHALL retrieve the entire 276 document, and that the fragment selection is applied by the 277 resolution client (e.g., browser) to the media returned by the 278 resolution service. In other words, in this latter case the 279 fragments are logical and physical components of the resource whereas 280 in the former cases these "fragments" are actually complete, 281 independently named entities. 283 Resources identified by NBNs are not always available in the 284 Internet. In that case, a surrogate such as a metadata record 285 describing the resource SHOULD be supplied. These records often 286 contain information about the physical location(s) of the item(s), or 287 links to related metadata records describing other (possibly digital) 288 manifestations of the work in question. 290 If an NBN identifies a work, descriptive metadata about the work 291 SHOULD be supplied. The metadata record can contain URI-based links 292 to Internet-accessible digital manifestations of the work. Metadata 293 records describing these manifestations can be interlinked and they 294 can also contain a URI linking them to the work level metadata 295 record. 297 Section 4 below, and in particular Section 4.3 therein, presents a 298 detailed overview of the application of the URN:NBN Namespace as well 299 as the principles of, and systems used for, the resolution of NBN- 300 based URNs. 302 4. National Bibliography Numbers (NBNs) 304 4.1. Overview 306 National Bibliography Number (NBN) is a generic term referring to a 307 group of identifier systems administered by the national libraries 308 and institutions authorized by them. The NBN assignment is typically 309 performed by the organization hosting the resource. National 310 libraries are committed to preserving their deposit collections for a 311 long time -- at least decades, but the aim is to provide access to 312 digital resources for centuries. 314 Each national library uses NBNs independently of other national 315 libraries; apart from this document, there is no global authority 316 that controls NBN usage. For this reason, NBNs as such are unique 317 only on the national level. When used as URNs, base NBN strings MUST 318 be augmented with a controlled prefix, which is the particular 319 nation's ISO 3166-1 alpha-2 two-letter country code. These prefixes 320 guarantee uniqueness of the URN:NBNs at the global scale [Iso3166MA]. 322 A national library using URN:NBNs SHOULD specify a local assignment 323 policy; such policy SHOULD limit the URN:NBN usage to the digital 324 resources stored permanently in the national library's deposit 325 collection. A more liberal URN:NBN assignment policy MAY be applied, 326 but NBNs assigned to a short-lived resources SHOULD NOT be made URN: 327 NBNs. 329 URN:NBN assignment policy SHOULD also clarify the local policy 330 concerning component resource identifier assignment and specify with 331 sufficient detail the syntax of local component identifiers (if such 332 exist as a discernible part of the NBNs). This syntax will only be 333 understood by the appropriate URN resolvers (that is, the resolvers 334 that deal with the namespace in question). The policy SHOULD also 335 cover any employed extensions to the default NBN scope (e.g., to 336 cover works or data elements). 338 4.2. Encoding Considerations and Lexical Equivalence 340 Expressing NBNs as URNs is usually straightforward, as traditionally 341 only ASCII characters have been used in NBN strings. If necessary, 342 NBNs must be translated into canonical form as specified in 343 RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn]. 345 When an NBN is used as a URN, the namespace-specific string (NSS) 346 MUST consist of three parts: 348 o a prefix, structured as a primary prefix, which is a two-letter 349 ISO 3166-1 country code, and zero or more secondary prefixes, each 350 indicated by a delimiting colon character (:) and a sub-namespace 351 identifier, 353 o a hyphen (-) as a delimiting character, and 355 o the NBN string. 357 The prefix is case-insensitive. An NBN string can be either case- 358 sensitive or case-insensitive, depending on the NBN syntax applied. 359 Future implementers of NBNs MAY make their NBN strings case- 360 insensitive. 362 Different delimiting characters are not semantically equivalent. 364 Use of colon as the delimiting character is allowed if and only if 365 the country code-based NBN namespace (identified by the respective 366 ISO 3166-1 country code used as the primary part of the prefix) is 367 split further into smaller sub-namespaces, in which case the colon 368 separates the ISO 3166-1 country code from the sub-namespace 369 identifier. These sub-divisions (including the colon separator) form 370 an optional part of the prefix. A colon MUST NOT be used for any 371 other purpose in the prefix. 373 A hyphen MUST be used for separating the prefix and the NBN string, 374 or the part of the NBN string that is assigned to the identified 375 object by a sub-division authority. 377 If there are several national libraries in one country, these 378 libraries MUST agree on how to divide the national namespace between 379 themselves using this method before the URN:NBN assignment begins in 380 any of these libraries. 382 A national library MAY also assign to trusted organization(s) such as 383 a university or a government institution its own NBN sub-namespace. 384 The sub-namespace MAY be further divided by the partner organization 385 (or by the national library on request of the partner). 387 Being part of the prefix, sub-namespace identifier strings are case- 388 insensitive. They MUST NOT contain any hyphens. 390 The sub-namespace identifiers used beneath a country-code-based 391 namespace MUST be registered on the national level by the national 392 library that assigned the code. The national register of these codes 393 SHOULD be made available online. 395 Models (indicated linebreak inserted for readability): 397 URN:NBN:- 399 URN:NBN::-\ 400 402 Examples (using actually assigned NBNs): 404 URN:NBN:fi-fe201003181510 406 urn:nbn:ch:bel-9039 408 urn:nbn:se:uu:diva-3475 410 urn:nbn:hu-3006 412 4.3. Resolution and Persistence of NBN-based URNs 414 Eventually, URNs might be resolved with the help of a resolver 415 discovery service (RDS). Since no such system has been installed yet 416 in the Internet, URN:NBNs are usually embedded in HTTP URIs in order 417 to make them actionable in the present Internet. In these HTTP URIs, 418 the authority part must point to the appropriate URN resolution 419 service. For instance, in Finland, the address of the national URN 420 resolver is . Thus the HTTP URI for the Finnish URN 421 in the example above is . 422 This public persistent identifier will not change. In contrast, 423 since the resource has already moved once from one DSpace system to 424 another, its DSpace-internal Handle has changed (to 425 https://helda.helsinki.fi/handle/10138/18199). Since Handles are in 426 this case only internal identifiers, they do not need to persist, and 427 users are asked to rely on the URN-based HTTP URI when they make 428 persistent links to the document. 430 The country code-based prefix part of the URN namespace-specific 431 string will provide a hint needed to find the correct national 432 resolution service for URN:NBNs from the resolver discovery service 433 when it is established. 435 There are three inter-related aspects of persistence that need to be 436 discussed: persistence of the objects itself, persistence of the 437 identifier, and persistence of the URN resolvers. 439 NBNs have traditionally been assigned to printed resources, which 440 tend to be persistent. In contrast, digital resources require 441 frequent migrations to guarantee accessibility. Although it is 442 impossible to estimate how often migrations are needed, hardware and 443 software upgrades take place frequently, and even a life time of 444 10-20 years can be considered as long. 446 Migration is often a lossy process, so different manifestations of a 447 resource may have different look and feel, and even different 448 intellectual content. Because of this, digital repositories usually 449 preserve each manifestation. In the URN:NBN namespace, each 450 manifestation SHOULD have a different identifier. 452 Different users will prefer different manifestations. A user who 453 requires authenticity probably wants the oldest version of the 454 resource, whereas a user to whom easy access is a priority is likely 455 to be satisfied with the latest manifestation. In order to enable 456 the users to find the best match, it is necessary to interlink URN: 457 NBNs belonging to the different manifestations of a resource to each 458 other (possibly via a work level metadata record) so as to make the 459 users aware of all the existing manifestations of the resource. 461 Thus, even if manifestations of digital resources are not and will 462 not be persistent per se, persistent identifiers such as URN:NBNs may 463 support construction of an information architecture which enables 464 persistent access to the requested intellectual content. 466 Persistence of URN resolvers themselves is mainly an organizational 467 issue, related to the persistence of organizations maintaining them. 468 As URN:NBN resolution services will be supplied (primarily) by the 469 national libraries to enable access to their (legal) deposit 470 collections, these services are likely to be long-lived. 472 4.4. Additional Considerations 474 URN:NBNs SHOULD NOT be assigned to resources that are known to not be 475 persistent (that is, resources that will simply disappear). URN:NBNs 476 MAY be applied to resources which have a low-level preservation 477 priority, including resources which are not migrated but only 478 preserved as bits. URN:NBN or other persistent identifier should be 479 applied to the documents which proioritized in the organisation's 480 preservation plan. It the identified manifestation has disappeared, 481 the resolution process SHOULD supply an alternative if one exists, 482 such as the original printed version which can be used when a 483 digitized surrogate has been lost or rendered unreadable. 485 5. URN Namespace ID Registration for the National Bibliography Number 486 (NBN) 488 This URN Namespace registration describes how National Bibliography 489 Numbers (NBNs) can be supported within the URN framework; it uses the 490 template from RFC 3406bis [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg]. 492 [[ RFC Editor: please replace "XXXX" in all instances of "RFC XXXX" 493 below by the RFC number assigned to this document. ]] 495 Namespace ID: NBN 497 This Namespace ID was formally assigned to the National 498 Bibliography Number in October 2001 when the namespace was 499 registered officially. Utilization of URN:NBNs had started in 500 demo systems already in 1998. Since 2001, tens of millions of 501 URN:NBNs have been assigned. The number of users of the namespace 502 has grown in two ways: new national libraries have started using 503 NBNs, and some national libraries using the system have formed new 504 liaisons. 506 Kind of named resources: 508 Preserved publications at the work, manifestation, or data element 509 level -- or their metadata. 511 Registration Information: 513 Version: 4 514 Date: 2012-10-22 516 Declared registrant of the namespace: 518 Name: Juha Hakala 519 Affiliation: Senior Adviser, The National Library of Finland 520 Email: juha.hakala@helsinki.fi 521 Postal: P.O.Box 15, 00014 Helsinki University, Finland 522 Web URL: http://www.nationallibrary.fi/ 524 The National Library of Finland registered the namespace on behalf 525 of the Conference of the European National Librarians (CENL) and 526 Conference of Directors of National Libraries (CDNL), which have 527 both made a commitment in 1998 to foster the use of URNs. The NBN 528 namespace is available for free for the national libraries. They 529 MAY allow other organizations to assign URN:NBNs and use the 530 resolution services established by the library for free or for a 531 fee. The fees, if collected, SHOULD be based on, e.g., the 532 maintenance costs of the system. 534 Declaration of syntactic structure of NSS part: 536 The namespace-specific string (NSS) will consist of three parts: 538 * a prefix, consisting of an ISO 3166-1 alpha-2 country code and 539 optional sub-namespace code(s) separated by colon(s), 541 * a hyphen (-) as the delimiting character, and 543 * an NBN string assigned by the national library or sub-delegated 544 authority. 546 Formal declaration of the NSS, using ABNF [RFC5234]: 548 nbn_nss = prefix "-" nbn_string 550 prefix = iso_cc *( ":" subspc ) 551 ; the entire prefix is case-insensitive 553 iso_cc = 2ALPHA 554 ; country code as assigned by ISO 3166, part 1 -- 555 ; identifies the national library 556 ; to which the branch is delegated 558 subspc = 1*(ALPHA / DIGIT) 559 ; as assigned by the respective national library 561 nbn_string = 562 ; MUST adhere to RFC 3986 syntax; 563 ; parsers must regard nbn_strings as case-sensitive 565 Colon MAY be used as a delimiting character only within the 566 prefix, between ISO 3166-1 country code and sub-namespace code(s), 567 which split the national namespace into smaller parts. 569 Whereas the prefix is regarded as case-insensitive, NBN-strings 570 MAY be case-sensitive at the preference of the assigning 571 authority; parsers therefore MUST treat these as case-sensitive; 572 any case mapping needed to introduce case-insensitivity MUST be 573 implemented in the responsible resolution system. 575 Hyphen MUST be used as the delimiting character between the prefix 576 and the NBN string. Within the NBN string, hyphen MAY be used for 577 separating different sections of the identifier from one another. 579 All two-letter codes are reserved by the ISO 3166 Maintenance 580 Agency for either existing and possible future ISO country codes 581 (or for private use). 583 Sub-namespace identifiers MUST be registered on the national level 584 by the national library that assigned the code. The list of such 585 identifiers SHOULD be available via the Web. 587 See Section 4.2 of RFC XXXX for examples. 589 Relevant ancillary documentation: 591 National Bibliography Number (NBN) is a generic name referring to 592 a group of identifier systems used by the national libraries and 593 their partner organizations for identification of deposited 594 publications and other resources (and their component parts) that 595 lack a 'canonical' identifier. In the future, the scope of NBN 596 can be extended to include, e.g., intellectual works and metadata 597 elements. Each national library uses NBNs independently of other 598 national libraries; there is neither a general standard defining 599 the NBN syntax nor a global authority to control the use of these 600 identifier systems. 602 The syntax of NBN strings is specified locally. NBNs used in 603 national bibliographies contain only characters that belong to the 604 US-ASCII character set. Following the expansion of the NBN scope 605 and semi- and fully automated NBN assignment processes, some 606 future NBNs MAY contain characters that MUST be translated into 607 canonical form according to the specifications in RFC 2141bis 608 [I-D.ietf-urnbis-rfc2141bis-urn]. 610 Conformance with URN syntax: 612 The NSS syntax specified in this registration is in full 613 conformance with RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn] and 614 its predecessor. 616 Rules for lexical equivalence of NSS part: 618 The prefix, consisting of an ISO 3166-1 country code and its 619 (optional) sub-divisions, is case-insensitive. The NBN string MAY 620 be case-sensitive or case-insensitive, depending on the rules 621 chosen by the NBN authority designated by the prefix; therefore, 622 general-purpose resolver clients without sub-namespace specific 623 knowledge) MUST treat NBN strings as case-sensitive. Syntax 624 requirements expressed in RFC 2141bis 625 [I-D.ietf-urnbis-rfc2141bis-urn] MUST be taken into account. 627 Formally, two URN:NBNs are lexically equivalent if they are octet- 628 by-octet equal after the following (conceptional) preprocessing: 629 1. normalize the case of the leading "urn:" token; 630 2. normalize the case of the prefix (country code and its optional 631 sub-divisions); 632 3. normalize the case of any percent-encoding; 634 Note: The case used in the normalization steps is a local matter; 635 implementations can normalize to lower or upper case as they see 636 fit, they only need to do it consistently. 638 Usage of query instructions: 640 URN:NBN resolvers MAY support several global services. Some of 641 them have been specified in RFC 2483; some remain unspecified. 642 Examples of existing relevant services are URI to URL or URLs, URI 643 to URN or URNs, URI to resource or resources, and URI to URC or 644 URCs. The component directive is relevant especially to the URI 645 to URC service, where it can be used to, e.g., indicate the 646 preferred metadata format or the completeness of the metadata 647 record or the metadata content requested such as table of 648 contents. A URN resolver maintained by a national library can 649 consult for instance the national bibliography, digital asset 650 management systems and digital preservation systems to supply 651 these services. 653 Examples of services that can be specified and implemented in the 654 future: request the oldest and most original manifestation of the 655 resource; request the latest version of the resource, and request 656 metadata related to the work. 658 Usage of fragment part: 660 If URI-to-resource service is used and the media type supports the 661 use of URI fragment parts, the users can utilize that to indicate 662 locations within the identified resources since NBNs should be 663 assigned to one and only one manifestation of a resource. 665 The URN:NBN Namespace does not impose any restrictions of its own 666 on the fragment identifiers allowed, beyond what the respective 667 media type admits. 669 It is also possible to specify a local fragment syntax. By 670 default, such syntax will be understood only by the URN resolvers 671 dedicated to the relevant URN:NBN sub-namespace. This syntax can 672 be utilized when it is impractical to assign URN:NBNs to all 673 component resources; for instance, a linguistic database can get a 674 single URN:NBN, and each concept in the database can be identified 675 with a fragment. 677 Identifier uniqueness and persistence considerations: 679 NBNs as such are not unique; different national libraries can 680 assign the same NBN to different documents. Therefore, something 681 must be done to guarantee the uniqueness of the URN:NBNs. The 682 prefix, based on the ISO country code, serves this purpose. URN: 683 NBNs, once given to the resource, MUST be persistent. 685 A URN:NBN, once it has been generated from a NBN, MUST NOT be re- 686 used for another resource. 688 Users of the URN:NBN namespace MUST ensure that they do not assign 689 the same URN:NBN twice. Different policies can be applied to 690 guarantee this. For instance, NBNs and corresponding URN:NBNs MAY 691 be assigned sequentially by programs in order to avoid human 692 mistakes. It is also possible to use printable representations of 693 checksums such as SHA-1 [RFC6234] or MD5 [RFC1321] as NBN, as long 694 as the registration process prevents collisions (irrespective of 695 the minuscule probability for these to occur). 697 Process of identifier assignment: 699 Assignment of NBN-based URNs MUST be controlled on national level 700 by the national library / national libraries. National guidelines 701 MAY differ, but the common denominator, however, is that the 702 identified resources themselves SHOULD be persistent. 704 Different URN:NBN assignment policies have resulted in varying 705 levels of control of the assignment process. Manual URN 706 assignment by the library personnel provides the tightest control, 707 especially if the URN:NBNs cover only resources catalogued into 708 the national bibliography. In most libraries, the scope of URN: 709 NBN is much broader than this. Usage rules MAY vary within one 710 country, from one URN:NBN sub-namespace to the next. As of yet, 711 there are no international guidelines for URN:NBN use beyond what 712 has been expressed in this document. 714 Process for identifier resolution: 716 See Section 4.3 of RFC XXXX. 718 Validation mechanism: 720 None specified on the global level (beyond a routine check of 721 those characters that require special encoding when employed in 722 URIs). NBNs may have a well specified and rich syntax (including, 723 e.g., fixed length and checksum). In such case, it is possible to 724 validate the correctness of the NBN programmatically. 726 Scope: 728 NBNs are applied to resources held in the collections of national 729 libraries and their partner organizations. NBNs may also be used 730 to identify, e.g., works that these resources manifest, and the 731 individual data elements present in the resource metadata. 733 6. Security Considerations 735 This document proposes means of encoding NBNs as URNs. A URN 736 resolution service for NBN-based URNs is depicted, but only at a 737 generic level; thus, questions of secure or authenticated resolution 738 mechanisms and authentication of users are out of scope of this 739 document. It does not deal with means of validating the integrity or 740 authenticating the source or provenance of URN:NBNs. Issues 741 regarding intellectual property rights associated with objects 742 identified by the URN:NBNs are also beyond the scope of this 743 document, as are questions about rights to the databases that might 744 be used to construct resolution services. 746 Beyond the generic security considerations laid out in the underlying 747 documents listed in the Normative References (Section 9.1), no 748 specific security threats have been identified for NBN-based URNs. 750 7. IANA Considerations 752 IANA is asked to update the existing registration of the Formal URN 753 Namespace 'NBN' using the template given above in Section 5. 755 [[ Editorial Note: this section to be amended by text on URN Query 756 Parameter registries, once discussion on versions -03 of rfc2141bis 757 and rfc3406bis drafts has settled. ]] 759 8. Acknowledgements 761 Revision of RFC 3188 started during the project PersID 762 (). Later the revision was included in the 763 charter of the URNbis working group in the Applications Area. The 764 author wishes to thank his colleagues in the PersID project and the 765 URNbis participants for their support and review comments. 767 Tommi Jauhiainen has provided feedback on an early version of this 768 draft. The authors wish to thank Tommi Jauhiainen, Bengt Neiss, and 769 Lars Svensson for the comments they have provided to various versions 770 of this draft. 772 9. References 774 9.1. Normative References 776 [I-D.ietf-urnbis-rfc2141bis-urn] 777 Hoenes, A., "Uniform Resource Name (URN) Syntax", 778 draft-ietf-urnbis-rfc2141bis-urn-03 (work in progress), 779 October 2012. 781 [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg] 782 Hoenes, A., "Defining Uniform Resource Name (URN) 783 Namespaces", draft-ietf-urnbis-rfc3406bis-urn-ns-reg-03 784 (work in progress), October 2012. 786 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 787 Requirement Levels", BCP 14, RFC 2119, March 1997. 789 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 790 Resource Identifier (URI): Generic Syntax", STD 66, 791 RFC 3986, January 2005. 793 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 794 Specifications: ABNF", STD 68, RFC 5234, January 2008. 796 9.2. Informative References 798 [I-D.ietf-urnbis-rfc3187bis-isbn-urn] 799 Huttunen, M., Hakala, J., and A. Hoenes, "Using 800 International Standard Book Numbers as Uniform Resource 801 Names", draft-ietf-urnbis-rfc3187bis-isbn-urn-03 (work in 802 progress), October 2012. 804 [IANA-URI] 805 IANA, "URI Schemes Registry", 806 . 808 [IANA-URN] 809 IANA, "URN Namespace Registry", 810 . 812 [Iso3166MA] 813 ISO, "ISO Maintenance agency for ISO 3166 country codes", 814 . 816 [RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, 817 April 1992. 819 [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail 820 Extensions (MIME) Part Two: Media Types", RFC 2046, 821 November 1996. 823 [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. 825 [RFC2288] Lynch, C., Preston, C., and R. Jr, "Using Existing 826 Bibliographic Identifiers as Uniform Resource Names", 827 RFC 2288, February 1998. 829 [RFC2611] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, 830 "URN Namespace Definition Mechanisms", BCP 33, RFC 2611, 831 June 1999. 833 [RFC3044] Rozenfeld, S., "Using The ISSN (International Serial 834 Standard Number) as URN (Uniform Resource Names) within an 835 ISSN-URN Namespace", RFC 3044, January 2001. 837 [RFC3187] Hakala, J. and H. Walravens, "Using International Standard 838 Book Numbers as Uniform Resource Names", RFC 3187, 839 October 2001. 841 [RFC3188] Hakala, J., "Using National Bibliography Numbers as 842 Uniform Resource Names", RFC 3188, October 2001. 844 [RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, 845 "Uniform Resource Names (URN) Namespace Definition 846 Mechanisms", BCP 66, RFC 3406, October 2002. 848 [RFC6234] Eastlake, D. and T. Hansen, "US Secure Hash Algorithms 849 (SHA and SHA-based HMAC and HKDF)", RFC 6234, May 2011. 851 Appendix A. Significant Changes from RFC 3188 853 Numerous clarifications based on a decade of experience with 854 RFC 3188. 856 Non-ISO 3166 (country code) based NBNs have been removed due to lack 857 of usage. 859 In accordance with established practice, the whole NBN prefix is now 860 declared case-insensitive. 862 Updated URN:NBN Namespace Registration template for IANA; whole 863 document adapted to new URN Syntax document, RFC 2141bis, and new URN 864 Namespace Registration document, RFC 3406bis. 866 Use of query directives and fragment parts with this Namespace is now 867 specified, in accordance with the aforementioned RFCs. 869 Appendix B. Draft Change Log 871 [[ RFC-Editor: Whole section to be deleted before RFC publication. ]] 873 B.1. draft-hakala-rfc3188bis-nbn-urn-00 to draft-ietf-urnbis-*-00 875 - formal updates for a WG draft; no more "Updates: 2288"; 876 - introduced references to other URNbis WG documents; 877 - changes based on review by Tommi Jauhiainen; 878 - Sect. 3 restructured into namespace and community considerations; 879 - old Sect. 7 incorporated in new Sect. 3.1; 880 - Security Considerations: old Section 4.5 merged into Section 5; 881 - added guidelines for when two manifestations of the same work 882 should get different URN:NBNs; 883 - clarified role of ISO 3166/MA for ISO 3166-1 country codes; 884 - clarified role of non-ISO prefix registry maintaind by the LoC; 885 - resolved inconsistency in lexical equivalence rules: as already 886 specified for ISO alpha-2 country-codes, and in accordance with 887 established practice, the whole NBN prefix is now declared case- 888 insensitive; 889 - registration template adapted to rfc3406bis[-00]; 890 - numerous editorial fixes and enhancements. 892 B.2. draft-ietf-urnbis-rfc3188bis-nbn-urn-00 to -01 894 - Numerous changes to accommodate the outcome of the discussions; 895 - on the urn list; 896 - three different ways of identifying fragments specified; 897 - removed some redundant/irrelevant paragraphs/subsections; 898 - the "one manifestation, one URN" principle strenghtened; 899 - introduced the idea of interlinking manifestations; 900 - extended the scope of the NBN explicitly to works; 901 - added reference to S4.2 in namespace registration; 902 - numerous editorial fixes and enhancements. 904 B.3. draft-ietf-urnbis-rfc3188bis-nbn-urn-01 to -02 906 - Removed the possibility of using prefixes not based on country 907 codes; 908 - replaced all instances of the word object with resources; 909 - removed some redundant/irrelevant paragraphs/subsections; 910 - allowed the possibility for identifying data elements with NBNs; 911 - a few editorial fixes and enhancements. 913 B.4. draft-ietf-urnbis-rfc3188bis-nbn-urn-02 to -03 915 - improved text related to "prefix" in NSS; 916 - addressed issues with text related to case-sensitivity of NSS 917 strings; 918 - addressed comments and open details on requirements language; 919 - switched language to talk about "resource" instead of "object"; 920 - several more editorial fixes and enhancements. 922 B.5. draft-ietf-urnbis-rfc3188bis-nbn-urn-03 to -04 924 - specification of how to use URN query and fragment part based on 925 the revised versions of rfc2141bis and rfc3406bis; 926 - various textual improvements and clarifications, including: 927 - textual alignments with rfc3187bis draft vers. -03; 928 - multiple editorial fixes and improvements. 930 Authors' Addresses 932 Juha Hakala 933 The National Library of Finland 934 P.O. Box 15 935 Helsinki, Helsinki University FIN-00014 936 Finland 938 Email: juha.hakala@helsinki.fi 940 Alfred Hoenes (editor) 941 TR-Sys 942 Gerlinger Str. 12 943 Ditzingen D-71254 944 Germany 946 Email: ah@TR-Sys.de