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diff --git a/doc/rfc/rfc2288.txt b/doc/rfc/rfc2288.txt new file mode 100644 index 0000000..402782d --- /dev/null +++ b/doc/rfc/rfc2288.txt @@ -0,0 +1,563 @@ + + + + + + +Network Working Group C. Lynch +Request for Comments: 2288 Coalition for Networked Information +Category: Informational C. Preston + Preston & Lynch + R. Daniel + Los Alamos National Laboratory + February 1998 + + + Using Existing Bibliographic Identifiers + as + Uniform Resource Names + +Status of this Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (1998). All Rights Reserved. + +Abstract + + A system for Uniform Resource Names (URNs) must be capable of + supporting identifiers from existing widely-used naming systems. + This document discusses how three major bibliographic identifiers + (the ISBN, ISSN and SICI) can be supported within the URN framework + and the currently proposed syntax for URNs. + +1. Introduction + + The ongoing work of several IETF working groups, most recently in the + Uniform Resource Names working group, has culminated the development + of a syntax for Uniform Resource Names (URNs). The functional + requirements and overall framework for Uniform Resource Names are + specified in RFC 1737 [Sollins & Masinter] and the specification for + the URN syntax is RFC 2141 [Moats]. + + As part of the validation process for the development of URNs the + IETF working group has agreed that it is important to demonstrate + that the current URN syntax proposal can accommodate existing + identifiers from well established namespaces. One such + infrastructure for assigning and managing names comes from the + bibliographic community. Bibliographic identifiers function as names + for objects that exist both in print and, increasingly, in electronic + formats. This memo demonstrates the feasibility of supporting three + + + +Lynch, et. al. Informational [Page 1] + +RFC 2288 Bibligraphic Identifiers February 1998 + + + representative bibliographic identifiers within the currently + proposed URN framework and syntax. + + Note that this document does not purport to define the "official" + standard way of moving these bibliographic identifiers into URNs; it + merely demonstrates feasibility. It has not been developed in + consultation with these standards bodies and maintenance agencies + that oversee the existing bibliographic identifiers. Any actual + Internet standard for encoding these bibliographic identifiers as + URNs will need to be developed in consultation with the responsible + standards bodies and maintenance agencies. + + In addition, there are several open questions with regard to the + management and registry of Namespace Identifiers (NIDs) for URNs. + For purposes of illustration, we have used the three NIDs "ISBN", + "ISSN" and "SICI" for the three corresponding bibliographic + identifiers discussed in this document. While we believe this to be + the most appropriate choice, it is not the only one. The NIDs could + be based on the standards body and standard number (e.g. "US-ANSI- + NISO-Z39.56-1997" rather than "SICI"). Alternatively, one could lump + all bibliographic identifiers into a single "BIBLIOGRAPHIC" name + space, and structure the namespace-specific string to specify which + identifier is being used. Any final resolution of this must wait for + the outcome of namespace management discussions in the working group + and the broader IETF community. + + For the purposes of this document, we have selected three major + bibliographic identifiers (national and international) to fit within + the URN framework. These are the International Standard Book Number + (ISBN) [ISO1], the International Standard Serials Number (ISSN) + [NISO1,ISO2, ISO3], and the Serial Item and Contribution Identifier + (SICI) [NISO2]. An ISBN is used to identify a monograph (book). An + ISSN is used to identify serial publications (journals, newspapers) + as a whole. A SICI augments the ISSN in order to identify + individual issues of serial publications, or components within those + issues (such as an individual article, or the table of contents of a + given issue). The ISBN and ISSN are defined in the United States by + standards issued by the National Information Standards Organization + (NISO) and also by parallel international standards issued under the + auspices of the International Organization for Standardization (ISO). + NISO is the ANSI-accredited standards body serving libraries, + publishers and information services. The SICI code is defined by a + NISO document in the United States and does not have a parallel + international standards document at present. + + + + + + + +Lynch, et. al. Informational [Page 2] + +RFC 2288 Bibligraphic Identifiers February 1998 + + + Many other bibliographic identifiers are in common use (for example, + CODEN, numbers assigned by major bibliographic utilities such as OCLC + and RLG, national library numbers such as the Library of Congress + Control Number) or are under development. While we do not discuss + them in this document, many of these will also need to be supported + within the URN framework as it moves to large scale implementation. + The issues involved in supporting those additional identifiers are + anticipated to be broadly similar to those involved in supporting + ISBNs, ISSNs, and SICIs. + +2. Identification vs. Resolution + + It is important to distinguish between the resource identified by a + URN and the resources a URN resolver that can reasonably return when + attempting to resolve an identifier. For example, the ISSN 0040-781X + identifies the popular magazine "Time" -- all of it, every issue for + from the start of publication to present. Resolving such an + identifier should not result in the equivalent of hundreds of + thousands of pages of text and photos being dumped to the user's + machine. It is more reasonable for ISSNs to resolve to a + navigational system, such as an HTML-based search form, so the user + may select issues or articles of interest. ISBNs and SICIs, on the + other hand, do identify finite, manageably-sized objects, but these + objects may still be large enough that resolution to a hierarchical + system is appropriate. + + In addition, the materials identified by an ISSN, ISBN or SICI may + exist only in printed or other physical form, not electronically. + The best that a resolver may be able to offer is information about + where to get the physical resource, such as library holdings or a + bookstore or publisher order form. The URN Framework provides + resolution services that may be used to describe any differences + between the resource identified by a URN and the resource that would + be returned as a result of resolving that URN. + +3. International Standard Book Numbers + +3.1 Overview + + An International Standard Book Number (ISBN) identifies an edition of + a monographic work. The ISBN is defined by the standard + NISO/ANSI/ISO 2108:1992 [ISO1] + + Basically, an ISBN is a ten-digit number (actually, the last digit + can be the letter "X" as well, as described below) which is divided + into four variable length parts usually separated by hyphens when + printed. The parts are as follows (in this order): + + + + +Lynch, et. al. Informational [Page 3] + +RFC 2288 Bibligraphic Identifiers February 1998 + + + * a group identifier which specifies a group of publishers, based on + national, geographic or some other criteria, + + * the publisher identifier, + + * the title identifier, + + * and a modulus 11 check digit, using X instead of 10. + + The group and publisher number assignments are managed in such a way + that the hyphens are not needed to parse the ISBN unambiguously into + its constituent parts. However, the ISBN is normally transmitted and + displayed with hyphens to make it easy for human beings to recognize + these parts without having to make reference to or have knowledge of + the number assignments for group and publisher identifiers. + +3.2 Encoding Considerations and Lexical Equivalence + + Embedding ISBNs within the URN framework presents no particular + encoding problems, since all of the characters that can appear in an + ISBN are valid in the identifier segment of the URN. %-encoding, as + described in [MOATS] is never needed. + + Example: URN:ISBN:0-395-36341-1 + + For the ISBN namespace, some additional equivalence rules are + appropriate. Prior to comparing two ISBN URNs for equivalence, it is + appropriate to remove all hyphens, and to convert any occurrences of + the letter X to upper case. + +3.3 Additional considerations + + The ISBN standard and related community implementation guidelines + define when different versions of a work should be assigned the same + or differing ISBNs. In actuality, however, practice varies somewhat + depending on publisher as to whether different ISBNs are assigned for + paperbound vs. hardbound versions of the same work, electronic vs. + printed versions of the same work, or versions of the same work + distinguished in some other way (e.g., published for example in the + US and in Europe). The choice of whether to assign a new ISBN or to + reuse an existing one when publishing a revised printing of an + existing edition of a work or even a revised edition of a work is + somewhat subjective. Practice varies from publisher to publisher + (indeed, the distinction between a revised printing and a new edition + is itself somewhat subjective). The use of ISBNs within the URN + framework simply reflects these existing practices. Note that it is + likely that an ISBN URN will often resolve to many instances of the + work (many URLs). + + + +Lynch, et. al. Informational [Page 4] + +RFC 2288 Bibligraphic Identifiers February 1998 + + +4. International Standard Serials Numbers + +4.1 Overview + + International Standard Serials Numbers (ISSN) identify a work that is + published on a continued basis in issues; they identify the entire + (often open-ended, in the case of an actively published) work. ISSNs + are defined by the international standards ISO 3297:1986 [ISO2] and + ISO/DIS 3297 [ISO3] and within the United States by NISO Z39.9-1992 + [NISO1]. The ISSN International Centre is located in Paris and + coordinates a network of regional centers. The National Serials Data + Program within the Library of Congress is the US Center of this + network. + + ISSNs have the form NNNN-NNNN where N is a digit, the last digit may + be an upper case X as the result of the check character calculation. + Unlike the ISBN the ISSN components do not have much structure; + blocks of numbers are passed out to the regional centers and + publishers. + +4.2 Encoding Considerations and Lexical Equivalence + + Again, there is no problem representing ISSNs in the namespace- + specific string of URNs since all characters valid in the ISSN are + valid in the namespace-specific URN string, and %-encoding is never + required. + + Example: URN:ISSN:1046-8188 + + Supplementary comparison rules are also appropriate for the ISSN + namespace. Just as for ISBNs, hyphens should be dropped prior to + comparison and occurrences of 'x' normalized to uppercase. + +4.3 Additional Considerations + + The ISSN standard and related community implementation guidelines + specify when new ISSNs should be assigned vs. continuing to use an + existing one. There are some publications where practice within the + bibliographic community varies from institution to institution, such + as annuals or annual conference proceedings. In some cases these are + treated as serials and ISSNs are used, and in some cases they are + treated as monographs and ISBNs are used. For example SIGMOD Record + volume 24 number 2 June 1995 contains the Proceedings of the 1995 ACM + SIGMOD International Conference on Management of Data. If you + subscribe to the journal (ISSN 0163-5808) this is simply the June + issue. On the other hand you may have acquired this volume as the + conference proceedings (a monograph) and as such would use the ISBN + 0-89791-731-6 to identify the work. There are also varying practices + + + +Lynch, et. al. Informational [Page 5] + +RFC 2288 Bibligraphic Identifiers February 1998 + + + within the publishing community as to when new ISSNs are assigned due + to the change in the name of a periodical (e.g. Atlantic becomes + Atlantic Monthly); or when a periodical is published both in printed + and electronic versions (e.g. The New York Times). The use of ISSNs + in URNs will reflect these judgments and practices. + +5. Serial Item and Contribution Identifiers + +5.1 Overview + + The standard for Serial Item and Contribution Identifiers (SICI) + codes, which has recently been extensively revised, is defined by + NISO/ANSI Z39.56-1997 [NISO2]. The maintenance agency for the SICI + code is the UnCover Corporation. + + SICI codes can be used to identify an issue of a serial, or a + specific contribution (e.g., an article, or the table of contents) + within an issue of a serial. SICI codes are not assigned, they are + constructed based on information about the issue or issue component + in question. + + The complete syntax for the SICI code will not be discussed here; see + NISO/ANSI Z39.56-1997 [NISO2] for details. However, an example and + brief review of the major components is needed to understand the + relationship with the ISSN and how this identifier differs from an + ISSN. An example of a SICI code is: 0015- + 6914(19960101)157:1<62:KTSW>2.0.TX;2-F + + The first nine characters are the ISSN identifying the serial title. + The second component, in parentheses, is the chronology information + giving the date the particular serial issue was published. In this + example that date was January 1, 1996. The third component, 157:1, + is enumeration information (volume, number) for the particular issue + of the serial. These three components comprise the "item segment" of + a SICI code. By augmenting the ISSN with the chronology and/or + enumeration information, specific issues of the serial can be + identified. The next segment, <62:KTSW>, identifies a particular + contribution within the issue. In this example we provide the + starting page number and a title code constructed from the initial + characters of the title. Identifiers assigned to a contribution can + be used in the contribution segment if page numbers are + inappropriate. The rest of the identifier is the control segment, + which includes a check character. Interested readers are encouraged + to consult the standard for an explanation of the fields in that + segment. + + + + + + +Lynch, et. al. Informational [Page 6] + +RFC 2288 Bibligraphic Identifiers February 1998 + + +5.2 Encoding Considerations and Lexical Equivalence + + The character set for SICIs is intended to be email-transport- + transparent, so it does not present major problems. However, all + printable excluded and reserved characters from the URN syntax are + valid in the SICI character set and must be %-encoded. + + Example of a SICI for an issue of a journal: + + URN:SICI:1046-8188(199501)13:1%3C%3E1.0.TX;2-F + + For an article contained within that issue: + + URN:SICI:1046-8188(199501)13:1%3C69:FTTHBI%3E2.0.TX;2-4 + + Equivalence rules for SICIs are not appropriate for definition as + part of the namespace and incorporation in areas such as cache + management algorithms. It is best left to resolver systems which try + to determine if two SICIs refer to the same content. Consequently, + we do not propose any specific rules for equivalence testing through + lexical manipulation. + +5.3 Additional Considerations + + Since the serial is identified by an ISSN, some of the ambiguity + currently found in the assignment of ISSNs carries over into SICI + codes. In cases where an ISSN may refer to a serial that exists in + multiple formats, the SICI contains a qualifier that specifies the + format type (for example, print, microform, or electronic). SICI + codes may be constructed from a variety of sources (the actual issue + of the serial, a citation or a record from an abstracting service) + and, as such are based on the principle of using all available + information, so there may be multiple SICI codes representing the + same article [NISO2, Appendix D]. For example, one code might be + constructed with access to both chronology and enumeration (that is, + date of issue and volume, issue and page number), another code might + be constructed based only on enumeration information and without + benefit of chronology. Systems that use SICI codes employ complex + matching algorithms to try to match SICI codes constructed from + incomplete information to SICI codes constructed with the benefit of + all relevant information. + + + + + + + + + + +Lynch, et. al. Informational [Page 7] + +RFC 2288 Bibligraphic Identifiers February 1998 + + +6. Security Considerations + + This document proposes means of encoding several existing + bibliographic identifiers within the URN framework. This document + does not discuss resolution; thus questions of secure or + authenticated resolution mechanisms are out of scope. It does not + address means of validating the integrity or authenticating the + source or provenance of URNs that contain bibliographic identifiers. + Issues regarding intellectual property rights associated with objects + identified by the various bibliographic identifiers are also beyond + the scope of this document, as are questions about rights to the + databases that might be used to construct resolvers. + +7. References + + [ISO1] NISO/ANSI/ISO 2108:1992 Information and documentation + -- International standard book number (ISBN) + [ISO2] ISO 3297:1986 Documentation -- International standard + serial numbering (ISSN) + [ISO3] ISO/DIS 3297 Information and documentation -- + International standard serial numbering (ISSN) (Revision of ISO + 3297:1986) + [Moats] Moats, R., "URN Syntax", RFC 2141, May 1997. + [NISO 1] NISO/ANSI Z39.9-1992 International standard serial + numbering (ISSN) + [NISO 2] NISO/ANSI Z39.56-1997 Serial Item and Contribution + Identifier + [Sollins & Masinter] Sollins, K., and L. Masinter, "Functional + Requirements for Uniform Resource Names", RFC 1737, December + 1994. + + + + + + + + + + + + + + + + + + + + + +Lynch, et. al. Informational [Page 8] + +RFC 2288 Bibligraphic Identifiers February 1998 + + +8. Authors' Addresses + + Clifford Lynch + Executive Director + Coalition for Networked Information + 21 Dupont Circle + Washington, DC 20036 + + EMail: cliff@cni.org + + + Cecilia Preston + Preston & Lynch + PO Box 8310 + Emeryville, CA 94662 + + EMail: cecilia@well.com + + + Ron Daniel Jr. + Advanced Computing Lab, MS B287 + Los Alamos National Laboratory + Los Alamos, NM, 87545 + + EMail: rdaniel@acl.lanl.gov + + + + + + + + + + + + + + + + + + + + + + + + + + +Lynch, et. al. Informational [Page 9] + +RFC 2288 Bibligraphic Identifiers February 1998 + + +9. Full Copyright Statement + + Copyright (C) The Internet Society (1998). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + + + + + + + + + + + + + + + + + + + + + + + + +Lynch, et. al. Informational [Page 10] + |