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Dublin Core Meta Tags

The Dublin Core is a fifteen-element metadata format that provides descriptive, technical, administrative, structural, and preservation information for archival management of web pages and also permits users to identify, locate, and retrieve archived pages. When used with consistency and thoroughness it provides significant benefits to web sites whose pages are to be archived. Like a catalog record, it can provide administrative as well as retrieval functions, that is to say it can be an effective tool for organizing and maintaing archived sets of pages as well as serving user nees to identify, locate, and retrieve them.

Two key objectives of the the Dublin Core Initiative are

Simplicity of creation and maintenance

The Dublin Core element set has been kept as small and simple as possible to allow a non-specialist to create simple descriptive records for information resources easily and inexpensively, while providing for effective retrieval of those resources in the networked environment.

Commonly understood semantics

Discovery of information across the vast commons of the Internet is hindered by differences in terminology and descriptive practices from one field of knowledge to the next. The Dublin Core can help the "digital tourist" -- a non-specialist searcher -- find his or her way by supporting a common set of elements, the semantics of which are universally understood and supported. For example, scientists concerned with locating articles by a particular author, and art scholars interested in works by a particular artist, can agree on the importance of a "creator" element. Such convergence on a common, if slightly more generic, element set increases the visibility and accessibility of all resources, both within a given discipline and beyond.

{source: Dublin Core User Guide}

The following table names and gives a brief description of each element.

Element	Element description
Creator	Person or organisation primarily responsible for creating the intellectual content of the resource, e.g. authors in the case of written documents, artists, photographers, etc. in the case of visual resources.
Publisher	The entity (e.g. agency including unit/branch/section) responsible for making the resource available in its present form, such as a publishing house, a university department, or a corporate entity.
Contributor	Person or organisation not specified in a Creator element who has made significant intellectual contributions to the resource but whose contribution is secondary to any person or organisation specified in a Creator element, e.g. editor, transcriber, illustrator.
Rights Management	A rights management statement, an identifier that links to a rights management statement.
Title	The name given to the resource, usually by the creator or publisher. Can be the same as the title of the resource, or may be more descriptive
Subject	The topic of the resource. Typically, will be expressed as keywords or phrases that describe the subject or content of the resource. Controlled vocabularies and formal classification schemes are encouraged.
Date	A date associated with the creation or availability of the resource.
Identifier	A string or number used to uniquely identify the resource. Examples for networked resources include URLs, Purls and URNs. ISBN or other formal names can be used.
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.
Source	The work, either print or electronic, from which this object is derived, if applicable. Source is not applicable if the present resource is in its original form.
Language	The language of the intellectual content of the resource.
Relation	Relationship to other resources, e.g. images in a document, chapters in a book, items in a collection.
Coverage	Spatial locations and temporal duration characteristic of the resource.
Type	The category of the resource, such as home page, novel, poem, working paper, technical report, essay, dictionary.
Format	The data format of the resource, used to identify the software and possibly hardware that might be needed to display or operate the resource, e.g. postscript, HTML, text, jpeg, XML.

The National Library of Australia's Guidelines for the Creation of Content for Resource Discovery Metadata gives help in locating the information needed to enter for each Dublin Core element. For example, it gives this guidance for the Description element:

1. This element provides a free-text summary that describes the resource. It is the least precise method of searching, but it can be useful for picking up terms not included in the SUBJECT element. It is also often used in the display of a search results list, helping the user to identify whether or not the resource appears relevant.
2. The DESCRIPTION element should provide objective information about the resource, not an evaluation or review.
3. Do not simply repeat the title in this element.
4. Use an abstract or other structured description included within the resource if available (but do not use quotation marks).
5. Otherwise, provide a brief outline of the content of the resource. It should supply enough information for a user to decide if the item is relevant.
6. Use the description to highlight any significant aspects of the resource.
7. Details of the format and date of the original version may also be included.
8. As some resource discovery systems display only a limited number of lines from the DESCRIPTION element, describe the most significant aspects of the resource in the beginning of the tag. A description of less than 255 characters is recommended to cater for as many systems as possible. Additional text may be useful for retrieval, but may not display.

Some resources on the Dublin Core meta tags

• DCMI Dublin Core Metadata Initiative from SEOConsultants.com (2009). Defines each elements and gives an example of its use.
• Using Dublin Core, by Diane Hillmann for the Dublin Core Metadata Initiative (2005). "This document is intended as an entry point for users of Dublin Core. For non-specialists, it will assist them in creating simple descriptive records for information resources (for example, electronic documents). Specialists may find the document a useful point of reference to the documentation of Dublin Core, as it changes and grows."
• Dublin Core Metadata Initiative, an initiative and open forum to develop interoperable online metadata standards. See also the Dublin Core FAQ.
• Using Dublin Core - The Elements from the Dublic Core Metatdata Initiative (2007). Gives guidelines for assigning meta tags and best practices for forming them.
• Dublin Core Metadata Best Practices (pdf) from the Collaborative Digitization Program Metadata Working Group - 2006.
• Expressing Dublin Core metadata using HTML/XHTML meta and link elements from the Dublin Core Metadata Initiative.
• Dublin Core Assistant from UKOLN. This is a small, flexible help utility for metadata applications that is intended to complement the help pages embedded within existing software.
• Dublin Core metadata editor from UKOLN, a Dublin Core generator which creates code for a few useful Dublin Core meta tags. The code can then be edited and inserted in the headers of web pages.
• Guidelines for the Creation of Content for Resource Discovery Metadata from the National Library of Australia.

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Credits

See the Top Page for general credits.

Image sources for this page: www.u.ac.uk, www.audettemedia.com, Library of Congress.

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