Dublin Core - Tagging the Web for better search and retrieval (2/3) - exploring XML | WebReference

Dublin Core - Tagging the Web for better search and retrieval (2/3) - exploring XML

Dublin Core - Tagging the Web for better search and retrieval

The DC Metadata Element Set

Out of this group comes the DC Metadata Element Set to the rescue. DCMES is an effort to define basic semantics for Web resources that can be mixed through namespaces with problem-specific meta data. DCMES has a couple of well-defined, straightforward elements:

ElementDefinitionRemarks
TitleA name given to the resource.Name by which the resource is formally known.
CreatorResponsible entity for the making of the resource.Could be a person, an organization, or a service.
SubjectThe topic of the content of the resource.Typically expressed as keywords, key phrases or classification codes. Ideally select a value from a controlled vocabulary or formal classification scheme.
DescriptionAn account of the content of the resource.Could be an abstract, table of contents, reference to a graphical representation of the content or a summary.
PublisherThe entity responsible for making the resource availableCan be same or different from creator
ContributorAn entity making contributions to the content of the resource.
Date A date associated with an event in the life cycle of the resource.Typically, Date will be associated with the creation or availability of the resource. Recommended best practice for encoding the date value is defined in a profile of ISO 8601 [W3CDTF] and follows the YYYY-MM-DD format.
TypeThe nature or genre of the content of the resource.Type includes terms describing general categories, functions, genres, or aggregation levels for content. Recommended best practice is to select a value from a controlled vocabulary (for example, the working draft list of Dublin Core Types [DCT1]). To describe the physical or digital manifestation of the resource, use the FORMAT element.
FormatThe physical or digital manifestation of the resource.Typically, Format may include the media-type or dimensions of the resource. Format may be used to determine the software, hardware or other equipment needed to display or operate the resource. Examples of dimensions include size and duration. Recommended best practice is to select a value from a controlled vocabulary (for example, the list of Internet Media Types [MIME] defining computer media formats).
IdentifierAn unambiguous reference to the resource within a given context.Recommended best practice is to identify the resource by means of a string or number conforming to a formal identification system. Example formal identification systems include the Uniform Resource Identifier (URI) (including the Uniform Resource Locator (URL)), the Digital Object Identifier (DOI) and the International Standard Book Number (ISBN).
SourceA Reference to a resource from which the present resource is derived.The present resource may be derived from the Source resource in whole or in part. Recommended best practice is to reference the resource by means of a string or number conforming to a formal identification system.
LanguageA language of the intellectual content of the resource.Recommended best practice for the values of the Language element is defined by RFC 1766 [RFC1766] which includes a two-letter Language Code (taken from the ISO 639 standard [ISO639]), followed optionally, by a two-letter Country Code (taken from the ISO 3166 standard [ISO3166]). For example, 'en' for English, 'fr' for French, or 'en-uk' for English used in the United Kingdom.
RelationA reference to a related resource.Recommended best practice is to reference the resource by means of a string or number conforming to a formal identification system.
CoverageThe extent or scope of the content of the resource.Coverage will typically include spatial location (a place name or geographic coordinates), temporal period (a period label, date, or date range) or jurisdiction (such as a named administrative entity). Recommended best practice is to select a value from a controlled vocabulary (for example, the Thesaurus of Geographic Names [TGN]) and that, where appropriate, named places or time periods be used in preference to numeric identifiers such as sets of coordinates or date ranges.
RightsInformation about rights held in and over the resource.Typically, a Rights element will contain a rights management statement for the resource, or reference a service providing such information. Rights information often encompasses Intellectual Property Rights (IPR), Copyright, and various Property Rights. If the Rights element is absent, no assumptions can be made about the status of these and other rights with respect to the resource.

These elements can be mixed with other vocabularies using the XML namespace facility. Let's look at a potential combination with RSS:

<?xml version="1.0"?> 
<rdf:RDF
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rss="http://purl.org/rss/1.0/"
  xmlns:dc="http://purl.org/dc/elements/1.1/"> 
  <rss:channel rdf:about="http://www.webreference.com/xml/index.rss"> 
    <rss:title>eXploringXML</rss:title> 
    <rss:link>http://exploringxml.com/</rss:link> 
    <dc:description>The Web master's resource on XML</dc:description> 
    <dc:subject>XML,tutorial,standard,tools,products</dc:subject> 
    <dc:identifier>http://www.exploringxml.com</dc:identifier> 
    <dc:creator>Michael Claßen</dc:publisher> 
    <dc:publisher>WebReference.com</dc:publisher> 
    <dc:rights>Copyright 2000, internet.com LLC</dc:rights> 
  </rss:channel> 
</rdf:RDF>

These elements can be further refined using qualifiers.

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URL: http://www.webreference.com/xml/column23/2.html
Created: Nov 05, 2000
Revised: Nov 05, 2000