Metadata : what for ?

I was wondering about how using metadata. It is not just matter of having a good reference system to found your stuff on google. You can use metada to: locate stuff (in the virtual world as well in real space), discover, select, manipulate/re-use, document, contextualise, manage, store, sort... According to the Nordic Metadata Project, metadata are :

data which describes a resource(s) or data which is associated with an object that describes that object. Basically, metadata is a description of objects, documents or services which may contain data about their form and content. The proposed set of 15 elements has emerged from an international effort of concensus building manifested through a series of workshops. Bibliographic records and catalog records used in libraries could be seen as one form of metadata.

Dublin Core is a nice metadata model made up of 15 elements which are embedded into HTML 2.0 or HTML 4.0: Title, Subject, Description, Creator, Publisher, Contributor, Date, Type, Format, Identifier, Source, Language, Relation, Coverage, Rights.

Example : <HTML> <HEAD> <TITLE>Test Page </TITLE> <META NAME="DC.TitleĀ” CONTENT="Test page at TECFA"> <META NAME="DC.Date" CONTENT="(SCHEME=ISO8601) 2004-01-13"> <META NAME="DC.Subject" CONTENT="test page to show how to use the Dublin Core metadata model"> <META NAME="DC.Description" CONTENT="Dublin Core is a nice metadata model made up of 15 elements."> <META NAME="DC.Creator" CONTENT="Nicolas Nova"> </HEAD>

Dublin Core Element descriptions :

1. TITLE. The name given to the resource by the CREATOR or PUBLISHER. 2. AUTHOR or CREATOR. The person(s) or organization(s) primarily responsible for the intellectual content of the resource. 3. SUBJECT or KEYWORDS. The topic of the resource, or keywords, phrases, or classification descriptors that describe the subject or content of the resource. 4. DESCRIPTION. A textual description of the content of the resource, including abstracts in the case of document-like objects or content description in the case of visual resources. 5. PUBLISHER. The entity responsible for making the resource available in its present form, such as a publisher, a university department, or a corporate entity. 6. OTHER CONTRIBUTORS. Person(s) or organization(s) in addition to those specified in the CREATOR element who have made significant intellectual contributions to the resource, but whose contribution is secondary to the individuals or entities specified in the CREATOR element. 7. DATE. The date the resource was made available in its present form. 8. RESOURCE TYPE. The category of the resource, such as home page, novel, poem, working paper, technical report, essay, dictionary. It is expected that RESOURCE TYPE will be chosen from enumerated list of types. 9. FORMAT. The data representation of the resource, such as text/html, ASCII, Postscript file, executable application, or JPEG image. FORMAT will be assigned from enumerated lists such as registered Internet Media Types (MIME types). The MIME types are defined according to the RFC2046 standard. Currently, the only option available is the text/html option. 10. RESOURCE IDENTIFIER. String or number used to uniquely identify the resource. Examples from networked resources include URLs and URNs (when implemented). 11. SOURCE. The work, either print or electronic, from which this resource is delivered, if applicable. 12. LANGUAGE. Language(s) of the intellectual content of the resource. 13. RELATION. Relationship to other resources. Formal specification of RELATION is currently under development. 14. COVERAGE. The spatial locations and temporal durations characteristics of the resource. Formal specification of COVERAGE is currently under development. 15. RIGHTS MANAGEMENT. The content of this element is intended to be a link (a URL or other suitable URI as appropriate) to a copyright notice, a rights-management statement, or perhaps a server that would provide such information in a dynamic way.