microdata - Microformats Wiki

microdata is part of WHATWG's HTML living specification that provides another way to embed microformats and poshformats vocabularies, and has been superseded by microformats2.
microdata was explicitly dropped by the W3C in 2013 (and therefore not part of W3C HTML5) due to a lack of interest by anyone to edit the spec and keep it up to date.[1]. It was later briefly re-adopted by W3C in 2017, updated a few times as recently as 2018, and then re-abandoned again in less than a year.
microdata consists of a set of attribute extensions to HTML:
For common semantics on the web (e.g. people+organizations, events, reviews, syndicated content), microformats are still simpler and easier than microdata, and are already well implemented across numerous tools and services.
For uncommon, rare, experimental, or one-off semantics:
Either way, such uncommon, rare, experimental, or one-off semantics in the wild should be documented so they may inform possible future microformats vocabularies.
microdata didn't happen overnight. Much of the design and simplicity of microdata is based on years of work on microformats principles deliberately designed to help guide and create simpler, more usable and accessible solutions. It happened so quickly because Ian Hickson designed microdata based upon years of work by both the microformats community, and the concept of using reverse-domain-names as unique qualifiers (popularized perhaps by Java programming language naming conventions).
most recently, lessons learned from the microdata parsing/data model were incorporated into microformats2 which now serves as a functional replacement thanks to the microformats2-parsing specification.
schema.rdfs.org has a list of tools.
Separate from the microdata specification, there are a number of microdata vocabularies, based on microformats and previous formats like vCard and iCalendar.
Formerly documented as a separate specification at http://dev.w3.org/html5/mdvcard/, the microdata vCard vocabulary is currently available as part of WHATWG additions to HTML.
If you're specifically looking to produce Google Rich Snippets, use hCard in addition to h-card.
Formerly documented as a separate specification at http://dev.w3.org/html5/mdvevent/, the microdata vEvent vocabulary is currently available as part of WHATWG additions to HTML.
If you're specifically looking to produce Google Rich Snippets, use hCalendar in addition to h-event.
Formerly documented as a separate specification at http://dev.w3.org/html5/mdwork/, the microdata Licensing Works vocabulary is currently available as part of WHATWG additions to HTML5.
The licensing microformat work provides a potential microformat alternative to the microdata Licensing Works vocabulary.
Please see: licensing-brainstorming and provide feedback.
For those that are ok with going with an HTML5 only solution, it may be interesting to consider and document a consistent way to use microformats and microformats vocabulary in microdata.
A possible simple implementation could look like this:
And here's an simple h-event example:
The advantage is that no major re-wiring in thinking is required to adjust real-world usage - but would parsers be able to deal with the change? And in fact, would this require a recasting of microformats themselves? --Epicurious 19:16, 16 August 2010 (UTC)
Since the introduction of XMDP, web authors have been able to define their specific uses of rel attribute values and class names.
(needs expansion with examples) ...