microdata

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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HTML living specification that provides another way to embed microformats and poshformats vocabularies, and has been superseded by microformats2.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 (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]

Contents

summary

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, microdata offers a simpler and easier to understand solution than alternatives that use namespaces like XML/RDF/RDFa. Developers should consider microdata as another way of expressing semantics that they may otherwise use poshformats for.

history

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.

parsers and tools

schema.rdfs.org has a list of tools.

microdata vocabularies

Separate from the microdata specification, there are a number of microdata vocabularies, based on microformats and previous formats like vCard and iCalendar.

microdata vCard vocabulary

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.

Note:

microdata vEvent vocabulary

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.

Note:

microdata Licensing Works vocabulary

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.

microformats in microdata

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:

<!DOCTYPE html>
<html lang="en">
<head>
<title>Corey Mwamba</title>
</head>
<body>
<section itemtype="http://microformats.org/profile/h-card" itemscope>
<h1 itemprop="name">Corey Mwamba</h1>
<p itemprop="street-address">56 Nowhere Road</p>
<p itemprop="locality">Nowhere</p>
<p itemprop="postal-code">NO1 6QT</p>
</div>
<a href="http://www.coreymwamba.co.uk/" itemprop="url">My web site</a>
</section>
</body>
</html>

And here's an simple h-event example:

<!DOCTYPE html>
<html lang="en">
<head>
<title>Web 2.0 Conference</title>
</head>
<body>
<div itemtype="http://microformats.org/profile/h-event" itemscope>
 <a itemprop="url" href="http://conferences.oreillynet.com/pub/w/40/program.html">
  http://conferences.oreillynet.com/pub/w/40/program.html
 </a>
 <span itemprop="summary">Web 2.0 Conference</span>: 
 <time itemprop="start" datetime="2005-10-05">October 5</time>-
 <time itemprop="end" datetime="2005-10-07">7</time>,
 at the <span itemprop="location">Argent Hotel, San Francisco, CA</span>
</div>
</body>
</html>

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)

alternatives

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) ...

see also

microdata was last modified: Sunday, August 24th, 2014

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