Microdata (HTML): Difference between revisions

Revision as of 20:31, 9 March 2011

Revision as of 21:56, 10 March 2011

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'''Microdata''' is a [[WHATWG]] [[HTML5]] specification used to nest [[semantics]] within existing content on web pages.<ref name="WHATWG"/> [[Search engines]], [[web crawlers]], and [[Web_browser|browsers]] can extract and process Microdata from a web page and use it to provide a richer browsing experience for users. Microdata use a supporting vocabulary to describe an item and name-value pairs to assign values to its properties.<ref name="DIVE"/> Microdata helps technologies such as search engines and web crawlers better understand what information is contained in a web page, providing better [[Search_engine_results_page|search results]]. Microdata is an attempt to provide a simpler way of annotating [[HTML_element|HTML elements]] with machine readable tags than the similar approaches of using [[RDFa]] and [[Microformats]].

== Microdata Vocabularies ==

Microdata vocabularies provide the [[semantics]], or meaning of an Item. Web developers can design a custom vocabulary or use vocabularies available on the web. A collection of commonly used (and Google Supported<ref name="GoogleRS"/>) Microdata vocabularies located at http://data-vocabulary.org which include: ''Person'', ''Event'', ''Organization'', ''Product'', ''Review'', ''Review-aggregate'', ''Breadcrumb'', ''Offer'', ''Offer-aggregate''. For some purposes, an ad-hoc vocabulary is adequate. For others, a vocabulary will need to be designed. Where possible, authors are encouraged to re-use existing vocabularies, as this makes content re-use easier.<ref name="WHATWG"/>

== Microdata Global Attributes ==

* <code>Itemscope</code> – Creates the Item and indicates that descendants of this [[HTML_element|element]] contain information about it.<ref name="WHATWG"/> This attribute precedes the <code>itemtype</code> attribute in the HTML element’s tag.

* <code>Itemtype</code> – A valid URL of a vocabulary that describes the item and its properties context.

* <code>ItemId</code> – Indicates a unique identifier of the item in the vocabulary.