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diff --git a/doc/rfc/rfc2413.txt b/doc/rfc/rfc2413.txt new file mode 100644 index 0000000..62e31ec --- /dev/null +++ b/doc/rfc/rfc2413.txt @@ -0,0 +1,451 @@ + + + + + + +Network Working Group S. Weibel +Request for Comments: 2413 OCLC Online Computer Library Center, Inc. +Category: Informational J. Kunze + University of California, San Francisco + C. Lagoze + Cornell University + M. Wolf + Reuters Limited + September 1998 + + + Dublin Core Metadata for Resource Discovery + +1. 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. + +2. Abstract + + The Dublin Core Metadata Workshop Series began in 1995 with an + invitational workshop which brought together librarians, digital + library researchers, content experts, and text-markup experts to + promote better discovery standards for electronic resources. The + Dublin Core is a 15-element set of descriptors that has emerged from + this effort in interdisciplinary and international consensus + building. This is the first of a set of Informational RFCs + describing the Dublin Core. Its purpose is to introduce the Dublin + Core and to describe the consensus reached on the semantics of each + of the 15 elements. + +3. Introduction + + Finding relevant information on the World Wide Web has become + increasingly problematic due to the explosive growth of networked + resources. Current Web indexing evolved rapidly to fill the demand + for resource discovery tools, but that indexing, while useful, is a + poor substitute for richer varieties of resource description. + + An invitational workshop held in March of 1995 brought together + librarians, digital library researchers, and text-markup specialists + to address the problem of resource discovery for networked resources. + + + + +Weibel, et. al. Informational [Page 1] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + + This activity evolved into a series of related workshops and + ancillary activities that have become known collectively as the + Dublin Core Metadata Workshop Series. + + The goals that motivate the Dublin Core effort are: + + - Simplicity of creation and maintenance + - Commonly understood semantics + - Conformance to existing and emerging standards + - International scope and applicability + - Extensibility + - Interoperability among collections and indexing systems + + These requirements work at cross purposes to some degree, but all are + desirable goals. Much of the effort of the Workshop Series has been + directed at minimizing the tensions among these goals. + + One of the primary deliverables of this effort is a set of elements + that are judged by the collective participants of these workshops to + be the core elements for cross-disciplinary resource discovery. The + term "Dublin Core" applies to this core of descriptive elements. + + Early experience with Dublin Core deployment has made clear the need + to support qualification of elements for some applications. Thus, a + Dublin Core element may be expressed without qualification (as + described in this RFC) or with qualifiers that refine its semantics + (the subject of future RFCs). For the sake of interoperability, + simple indexing and discovery tools should be able to ignore any + qualifiers provided, while more advanced, semantically richer tools + should be able to use qualifiers to support more specialized or + precise discovery. + + The broad agreements about syntax and semantics that have emerged + from the workshop series will be expressed in a series of + Informational RFCs, of which this document is the first. + +4. Description of Dublin Core Elements + + The following is the reference definition of the Dublin Core Metadata + Element Set. Further information about the Dublin Core Metadata + Element Set is available at [1]: + + http://purl.org/metadata/dublin_core + + In the element descriptions below, each element has a descriptive + name intended to convey a common semantic understanding of the + element, as well as a formal single-word label intended to make the + syntactic specification of elements simpler for encoding schemes. + + + +Weibel, et. al. Informational [Page 2] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + + Although some environments, such as HTML, are not case-sensitive, it + is recommended best practice always to adhere to the case conventions + in the element labels given below to avoid conflicts in the event + that the metadata is subsequently extracted or converted to a case- + sensitive environment, such as XML (Extensible Markup Language) [2]. + + Each element is optional and repeatable. Metadata elements may + appear in any order. The ordering of multiple occurrences of the + same element (e.g., Creator) may have a significance intended by the + provider, but ordering is not guaranteed to be preserved in every + system. + + To promote global interoperability, a number of the element + descriptions suggest a controlled vocabulary for the respective + element values. It is assumed that other controlled vocabularies + will be developed for interoperability within certain local domains. + + The metadata elements fall into three groups which roughly indicate + the class or scope of information stored in them: (1) elements + related mainly to the Content of the resource, (2) elements related + mainly to the resource when viewed as Intellectual Property, and (3) + elements related mainly to the Instantiation of the resource. + + Content Intellectual Property Instantiation + ----------- --------------------- ------------- + Title Creator Date + Subject Publisher Format + Description Contributor Identifier + Type Rights Language + Source + Relation + Coverage + +4.1. Title Label: "Title" + + The name given to the resource, usually by the Creator or Publisher. + +4.2. Author or Creator Label: "Creator" + + The person or organization primarily responsible for creating the + intellectual content of the resource. For example, authors in the + case of written documents, artists, photographers, or illustrators in + the case of visual resources. + + + + + + + + +Weibel, et. al. Informational [Page 3] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + +4.3. Subject and Keywords Label: "Subject" + + The topic of the resource. Typically, subject will be expressed as + keywords or phrases that describe the subject or content of the + resource. The use of controlled vocabularies and formal + classification schemes is encouraged. + +4.4. Description Label: "Description" + + A textual description of the content of the resource, including + abstracts in the case of document-like objects or content + descriptions in the case of visual resources. + +4.5. Publisher Label: "Publisher" + + The entity responsible for making the resource available in its + present form, such as a publishing house, a university department, or + a corporate entity. + +4.6. Other Contributor Label: "Contributor" + + A person or organization not specified in a Creator element who has + made significant intellectual contributions to the resource but whose + contribution is secondary to any person or organization specified in + a Creator element (for example, editor, transcriber, and + illustrator). + +4.7. Date Label: "Date" + + A date associated with the creation or availability of the resource. + Recommended best practice is defined in a profile of ISO 8601 [3] + that includes (among others) dates of the forms YYYY and YYYY-MM-DD. + In this scheme, for example, the date 1994-11-05 corresponds to + November 5, 1994. + +4.8. Resource Type Label: "Type" + + The category of the resource, such as home page, novel, poem, working + paper, technical report, essay, dictionary. For the sake of + interoperability, Type should be selected from an enumerated list + that is currently under development in the workshop series. + +4.9. Format Label: "Format" + + The data format and, optionally, dimensions (e.g., size, duration) of + the resource. The format is used to identify the software and + possibly hardware that might be needed to display or operate the + + + + +Weibel, et. al. Informational [Page 4] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + + resource. For the sake of interoperability, the format should be + selected from an enumerated list that is currently under development + in the workshop series. + +4.10. Resource Identifier Label: "Identifier" + + A string or number used to uniquely identify the resource. Examples + for networked resources include URLs and URNs (when implemented). + Other globally-unique identifiers, such as International Standard + Book Numbers (ISBN) or other formal names are also candidates for + this element. + +4.11. Source Label: "Source" + + Information about a second resource from which the present resource + is derived. While it is generally recommended that elements contain + information about the present resource only, this element may contain + metadata for the second resource when it is considered important for + discovery of the present resource. + +4.12. Language Label: "Language" + + The language of the intellectual content of the resource. + Recommended best practice is defined in RFC 1766 [4]. + +4.13. Relation Label: "Relation" + + An identifier of a second resource and its relationship to the + present resource. This element is used to express linkages among + related resources. For the sake of interoperability, relationships + should be selected from an enumerated list that is currently under + development in the workshop series. + +4.14. Coverage Label: "Coverage" + + The spatial or temporal characteristics of the intellectual content + of the resource. Spatial coverage refers to a physical region (e.g., + celestial sector) using place names or coordinates (e.g., longitude + and latitude). Temporal coverage refers to what the resource is + about rather than when it was created or made available (the latter + belonging in the Date element). Temporal coverage is typically + specified using named time periods (e.g., neolithic) or the same + date/time format [3] as recommended for the Date element. + + + + + + + + +Weibel, et. al. Informational [Page 5] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + +4.15. Rights Management Label: "Rights" + + A rights management statement, an identifier that links to a rights + management statement, or an identifier that links to a service + providing information about rights management for the resource. + +5. Security Considerations + + The Dublin Core element set poses no risk to computers and networks. + It poses minimal risk to searchers who obtain incorrect or private + information due to careless mapping from rich data descriptions to + the simple Dublin Core scheme. No other security concerns are likely + to be raised by the element description consensus documented here. + +6. References + + [1] Further information about the Dublin Core Metadata Element Set, + http://purl.org/metadata/dublin_core + + [2] Extensible Markup Language (XML), http://www.w3.org/TR/REC-xml + + [3] Date and Time Formats (based on ISO 8601), W3C Technical Note, + http://www.w3.org/TR/NOTE-datetime + + [4] Alvestrand, H., "Tags for the Identification of Languages", RFC + 1766, March 1995. + +7. Authors' Addresses + + Stuart L. Weibel + OCLC Online Computer Library Center, Inc. + Office of Research + 6565 Frantz Rd. + Dublin, Ohio, 43017, USA + + Phone: +1 614-764-6081 + Fax: +1 614-764-2344 + EMail: weibel@oclc.org + + + + + + + + + + + + + +Weibel, et. al. Informational [Page 6] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + + John A. Kunze + Center for Knowledge Management + University of California, San Francisco + 530 Parnassus Ave, Box 0840 + San Francisco, CA 94143-0840, USA + + Phone: +1 510-525-8575 + Fax: +1 415-476-4653 + EMail: jak@ckm.ucsf.edu + + + Carl Lagoze + University Library and Department of Computer Science + Cornell University + Ithaca, NY 14853, USA + + Phone: +1 607-255-6046 + Fax: +1 607-255-4428 + EMail: lagoze@cs.cornell.edu + + + Misha Wolf + Reuters Limited + 85 Fleet Street + London EC4P 4AJ, UK + + Phone: +44 171-542-6722 + Fax: +44 171-542-8314 + EMail: misha.wolf@reuters.com + + + + + + + + + + + + + + + + + + + + + + +Weibel, et. al. Informational [Page 7] + +RFC 2413 Dublin Core Metadata for Resource Discovery September 1998 + + +8. 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. + + + + + + + + + + + + + + + + + + + + + + + + +Weibel, et. al. Informational [Page 8] + |