RDFa Lite is minimal subset of RDFa ... consisting of a few attributes that may be used to express [[machine-readable data]] in Web documents like HTML, SVG, and XML. While it is not a complete solution for advanced data markup tasks, it does work for most day-to-day needs and can be learned by most Web authors in a day.RDFa Lite consists of five attributes: vocab, typeof, property, resource, and prefix. RDFa 1.1 Lite is upwards compatible with RDFa 1.1. In 2009 the W3C was positioned[http://www.w3.org/html/wg/tracker/issues/76 Final W3C position] (ISSUE-76), establishing that Microdata syntax simply duplicates what RDFa Lite already does. to retain ''RDFa Lite'' as unique and definitive standard alternative to [[Microdata (HTML)|Microdata]].{{cite web|url=http://manu.sporny.org/2012/mythical-differences|title=Mythical Differences: RDFa Lite vs. Microdata - The Beautiful, Tormented Machine}} The position was confirmed with the publication of the HTML5 Recommendation in 2014. ==Essence== The essence of RDFa is to provide a set of attributes that can be used to carry metadata in an XML language (hence the 'a' in RDFa). These attributes are: ; {{mono|about}} : a [[URI]] or [[CURIE]] specifying the resource the metadata is about ; {{mono|rel}} and {{mono|rev}} : specifying a relationship and reverse-relationship with another resource, respectively ; {{mono|src}}, {{mono|[[href]]}} and {{mono|resource}} : specifying the partner resource ; {{mono|property}} : specifying a property for the content of an element or the partner resource ; {{mono|content}} : optional attribute that overrides the content of the element when using the property attribute ; {{mono|datatype}} : optional attribute that specifies the [[datatype]] of text specified for use with the property attribute ; {{mono|typeof}} : optional attribute that specifies the RDF type(s) of the subject or the partner resource (the resource that the metadata is about). ==Benefits== There are five "principles of interoperable metadata" met by RDFa.[http://assets.adida.net/presentations/w3c-2006-04-06/w3c-2006-04-06.pdf Building Interoperable Web Metadata] * Publisher Independence – each site can use its own standards * Data Reuse – data are not duplicated. Separate XML and HTML sections are not required for the same content. * Self Containment – the HTML and the RDF are separated * Schema Modularity – the attributes are reusable Additionally RDFa may benefit [[web accessibility]] as more information is available to [[Assistive Technology Service Provider Interface|assistive technology]].{{cite web|url=http://www.standards-schmandards.com/2007/rdfa-and-accessibility/|title=RDFa – Implications for Accessibility – Standards Schmandards}} ==Usage == There is a growing number of tools for better usage of RDFa vocabularies and RDFa annotation. === HTML+RDFa statistics === [[File:RDFa-UsageStatistics-charts.png|thumb|280px|2013 survey pizza charts of percentage usage, showing that 79% of URLs and 43% of domains use ''HTML+RDFa''. The average 61% (the other 39% was Microformats) is the ''usage indicator''.]] Simplified approaches to semantically annotate information items in [[webpages]] were greatly encouraged by the [[#HTML+RDFa|HTML+RDFa]] (released in 2008) and [[microformats]] (since ~2005) standards. {{As of | 2013}} these standards were encoding events, contact information, products, and so on. Despite the [[vCard]] semantics (only basic items of [[person]] and [[organization]] annotations) dominance,{{cite web |url=http://webdatacommons.org/structureddata/index.html#toc2 |date=2013 |work= section 3.1, "Extraction Results from the November 2013 Common Crawl Corpus" |access-date=2015-02-21 |title=Web Data Commons – RDFa, Microdata, and Microformat Data Sets}} and some [[boilerplate (text)|cloning]] of annotations along the same [[Domain name|domain]], the counting of webpages (URLs) and domains with annotations is an important statistical indicator for ''usage of semantically annotated information'' in the Web. The statistics of 2017 show that usage{{cite web|url=http://webdatacommons.org/structureddata/index.html#toc2 |date=2017 |work= section 3.1, "Extraction Results from the November 2017 Common Crawl Corpus" |access-date=2019-01-09 |title=Web Data Commons – RDFa, Microdata, and Microformat Data Sets}} of HTML+RDFa is now less than that of Microformats. === RDFa editors === ;Web-based RDFa editors: There are already a few RDFa editors available online. [[RDFaCE]] (RDFa Content Editor) is a [[WYSIWYM]] editor based on [[TinyMCE]] to support RDFa content authoring. It supports manual and semi-automatic generation of RDFa with the support of annotation services such as [[DBpedia Spotlight]], [[OpenCalais]], [[Alchemy API]], among others.{{cite web|url=http://aksw.org/Projects/RDFaCE|title=RDFaCE — Agile Knowledge Engineering and Semantic Web (AKSW)}} RDFaCE-Lite is a version of RDFaCE also supporting [[Microdata (HTML)|Microdata]] and available as a WordPress plugin.{{cite web|url=http://aksw.org/Projects/RDFaCE|title=RDFaCE — Agile Knowledge Engineering and Semantic Web (AKSW)}} ;Desktop RDFa editors: [[AutôMeta]] is an environment for semi-automatic (or automatic) annotation of documents for publishing on the Web using RDFa. It also includes an RDFa extraction tool to provide the user with a view of the annotated triples. It is available in both [[Command-line interface|CLI]] and [[GUI]] interfaces.{{cite web|url=http://code.google.com/p/autometa/|title=Google Code Archive - Long-term storage for Google Code Project Hosting.}} ===Examples=== The following is an example of adding [[Dublin Core]] metadata to an XML element in an XHTML file. Dublin Core data elements are data typically added to a book or article (title, author, subject etc.)
My name is John D and I like Einstürzende Neubauten.
My favorite book is the inspiring Weaving the Web by Tim Berners-Lee.
http://example.org/john-d/#me span element) contains a nickname for this person, and the ''dc:creator'' property (in the meta element) tells us who created the document. The hyperlink to the Einstürzende Neubauten website contains rel="foaf:interest", suggesting that John Doe is interested in this band. The URI of their website is a resource.
The ''foaf:interest'' inside the second p element is referring to a book by ISBN. The resource attribute defines a resource in a similar way to the href attribute, but without defining a hyperlink. Further into the paragraph, a span element containing an about attribute defines the book as another resource to specify metadata about. The book title and author are defined within the contents of this tag using the ''dc:title'' and ''dc:creator'' properties.
Here are the same triples when the above document is automatically converted to [[RDF/XML]]:
My name is John D and I like Einstürzende Neubauten.
My favorite book is the inspiring Weaving the Web by Tim Berners-Lee.
Welcome to my blog.
vocab, typeof, property; not only one of them.
'''RDFa Structured Data Example'''
Person Schema in RDFa.{{Cite web |last=Murari |first=Krishna |date=19 January 2023 |title=Person Schema in RDFa |url=https://www.theseotoday.com/2023/01/schema-markup-guide.html |url-status=live |archive-url=https://web.archive.org/web/20230119083602/https://www.theseotoday.com/2023/01/structured-data-guide.html |archive-date=19 January 2023 |access-date=19 January 2023 |website=The Seo Today}}