|Organization||Google, Yahoo, Microsoft, Yandex, W3C|
|Base Standards||URI, HTML5, RDF, Microdata, ISO 8601|
|Related Standards||RDFa, Microformat, RDFS, OWL, N-Triples, Turtle, JSON, JSON-LD, CSV|
Schema.org is an initiative launched on 2 June 2011 by Bing, Google and Yahoo! (the operators of the then world's largest search engines) to “create and support a common set of schemas for structured data markup on web pages.” On 1 November Yandex (whose search engine is the largest one in Russia) joined the initiative. They propose using their ontology and Microdata in HTML5 to mark up website content with metadata about itself. Such markup can be recognized by search engine spiders and other parsers, thus gaining access to the meaning of the sites (see Semantic Web). The initiative started with a small number of formats, but the long term goal is to support a wider range of schemas. The initiative also describes an extension mechanism for adding additional properties. A mailing list is provided, for discussion of the initiative.
Much of the vocabulary on schema.org was inspired by earlier formats such as Microformats, FOAF, GoodRelations and OpenCyc. Microformats such as hCard, however, continue to be published more than schema and others on the web.
To test the validity of the data marked up with the schemas and Microdata, such validators as Google Rich Snippets Validator, Yandex Microformat validator and Bing Markup Validator can be used.
The following is an example of how to mark up information about a movie and its director using the schema.org schemas and microdata. In order to mark up the data the attribute
itemtype along with the url of the schema is used. The attribute
itemscope defines the scope of the itemtype. The kind of the current item can be defined by using the attribute
<div itemscope itemtype="http://schema.org/Movie"> <h1 itemprop="name">Avatar</h1> <div itemprop="director" itemscope itemtype="http://schema.org/Person"> Director: <span itemprop="name">James Cameron</span> (born <time itemprop="birthDate" datetime="1954-08-16">August 16, 1954</time>) </div> <span itemprop="genre">Science fiction</span> <a href="../movies/avatar-theatrical-trailer.html" itemprop="trailer">Trailer</a> </div>
RDFa 1.1 Lite
<div vocab="http://schema.org/" typeof="Movie"> <h1 property="name">Avatar</h1> <div property="director" typeof="Person"> Director: <span property="name">James Cameron</span> (born <time property="birthDate" datetime="1954-08-16">August 16, 1954</time>) </div> <span property="genre">Science fiction</span> <a href="../movies/avatar-theatrical-trailer.html" property="trailer">Trailer</a> </div>
- Introducing schema.org: Search engines come together for a richer web, Google blog, 2 June 2011
- Introducing Schema.org: Bing, Google and Yahoo Unite to Build the Web of Objects, Bing blog, 2 June 2011
- Introducing schema.org: A Collaboration on Structured Data, Yahoo blog, 2 June 2011
- "Top 5 Search Engines from Oct to Dec 10". StatCounter. Retrieved 17 January 2011.
- Techcrunch "Yandex joins Google, Yahoo! and Bing to collaborate on Schema.org"
- Schema Blog "Yandex now supports schema.org markup"
- Getting started guide
- "Extending Schemas". schema.org. 2011-06-02. Retrieved 2 June 2011.
- "W3C Schema.org mailing list". w3.org. 2013-07-22. Retrieved 22 July 2013.
- "FAQ". schema.org. Retrieved 2 June 2011.
- "Web Data Commons: Extracting Structured Data from the Common Web Crawl". 2012-03-22: Extraction results from the 2012 Common Crawl corpus available for download, 2012-03-13: Extraction results from the 2009/2010 Common Crawl corpus available for download. 2012-03-22. Retrieved 2012-04-09.
- Microdata2RDF - a REST service extracting RDF from Microdata semantic annotations
- Google Rich Snippets Testing Tool
- Yandex Microformat validator
- Bing Markup Validator
- Getting started with schema.org -- Example
- Schema.org Parser/Maker
- schema.rdfs.org RDF, Turtle, JSON, CSV
- schema.org/docs/schema_org_rdfa.html RDFa
- schema.org/docs/schemaorg.owl OWL
- original discussion group, now moved to W3C
- GetSchema Annotating HTML5 with Schema.org and Microdata. An Example Wiki.