Microformat

Microformats emerged around 2005[note 1] as part of a grassroots movement to make recognizable data items (such as events, contact details or geographical locations) capable of automated processing by software, as well as directly readable by end-users.[3][note 2] Link-based microformats emerged first. These include vote links that express opinions of the linked page, which search engines can tally into instant polls.[4]

CommerceNet, a nonprofit organization that promotes e-commerce on the Internet, has helped sponsor and promote the technology and support the microformats community in various ways.[4] CommerceNet also helped co-found the Microformats.org community site.[4]

Neither CommerceNet nor Microformats.org operates as a standards body. The microformats community functions through an open wiki, a mailing list, and an Internet relay chat (IRC) channel.[4] Most of the existing microformats originated at the Microformats.org wiki and the associated mailing list by a process of gathering examples of web-publishing behaviour, then codifying it. Some other microformats (such as rel=nofollow and unAPI) have been proposed, or developed, elsewhere.

XHTML and HTML standards allow for the embedding and encoding of semantics within the attributes of markup elements. Microformats take advantage of these standards by indicating the presence of metadata using the following attributes:

class

Classname

rel

relationship, description of the target address in an anchor-element (<a href=... rel=...>...</a>)

rev

reverse relationship, description of the referenced document (in one case, otherwise deprecated in microformats[5])

For example, in the text "The birds roosted at 52.48, -1.89" is a pair of numbers which may be understood, from their context, to be a set of geographic coordinates. With wrapping in spans (or other HTML elements) with specific class names (in this case geo, latitude and longitude, all part of the geo microformat specification):

The birds roosted at
   <span class="geo">
     <span class="latitude">52.48</span>,
     <span class="longitude">-1.89</span>
   </span>

software agents can recognize exactly what each value represents and can then perform a variety of tasks such as indexing, locating it on a map and exporting it to a GPS device.

 <ul>
   <li>Joe Doe</li>
   <li>The Example Company</li>
   <li>604-555-1234</li>
   <li><a href="http://example.com/">http://example.com/</a></li>
 </ul>

 <ul class="vcard">
   <li class="fn">Joe Doe</li>
   <li class="org">The Example Company</li>
   <li class="tel">604-555-1234</li>
   <li><a class="url" href="http://example.com/">http://example.com/</a></li>
 </ul>

Several microformats have been developed to enable semantic markup of particular types of information. However, only hCard and hCalendar have been ratified, the others remaining as drafts:

• hAtom (superseded by h-entry and h-feed) – for marking up Atom feeds from within standard HTML
• hCalendar – for events
• hCard – for contact information; includes:
  • adr – for postal addresses
  • geo – for geographical coordinates (latitude, longitude)
• hMedia – for audio/video content[6][7]
• hAudio – for audio content
• hNews – for news content
• hProduct – for products
• hRecipe – for recipes and foodstuffs.
• hResume – for resumes or CVs
• hReview – for reviews
• rel-directory – for distributed directory creation and inclusion[8]
• rel-enclosure – for multimedia attachments to web pages[9]
• rel-license – specification of copyright license[10]
• rel-nofollow, an attempt to discourage third-party content spam (e.g. spam in blogs)
• rel-tag – for decentralized tagging (Folksonomy)[11]
• xFolk – for tagged links
• XHTML Friends Network (XFN) – for social relationships
• XOXO – for lists and outlines

Using microformats within HTML code provides additional formatting and semantic data that applications can use. For example, applications such as web crawlers can collect data about on-line resources, or desktop applications such as e-mail clients or scheduling software can compile details. The use of microformats can also facilitate "mash ups" such as exporting all of the geographical locations on a web page into (for example) Google Maps to visualize them spatially.

Several browser extensions, such as Operator for Firefox and Oomph for Internet Explorer, provide the ability to detect microformats within an HTML document. When hCard or hCalendar are involved, such browser extensions allow microformats to be exported into formats compatible with contact management and calendar utilities, such as Microsoft Outlook. When dealing with geographical coordinates, they allow the location to be sent to applications such as Google Maps. Yahoo! Query Language can be used to extract microformats from web pages.[12] On 12 May 2009 Google announced that they would be parsing the hCard, hReview and hProduct microformats, and using them to populate search result pages.[13] They subsequently extended this in 2010 to use hCalendar for events and hRecipe for cookery recipes.[14] Similarly, microformats are also processed by Bing[15] and Yahoo!.[16] As of late 2010, these are the world's top three search engines.[17]

Microsoft said in 2006 that they needed to incorporate Microformats into upcoming projects,[18] as did other software companies.

Alex Faaborg summarizes the arguments for putting the responsibility for microformat user interfaces in the web browser rather than making more complicated HTML:[19]

• Only the web browser knows what applications are accessible to the user and what the user's preferences are
• It lowers the barrier to entry for web site developers if they only need to do the markup and not handle "appearance" or "action" issues
• Retains backwards compatibility with web browsers that don't support microformats
• The web browser presents a single point of entry from the web to the user's computer, which simplifies security issues

Various commentators have offered review and discussion on the design principles and practical aspects of microformats. Microformats have been compared to other approaches that seek to serve the same or similar purpose.[20] As of 2007, there had been some criticism of one, or all, microformats.[20] The spread and use of microformats was being advocated as of 2007.[21][22] Opera Software CTO and CSS creator Håkon Wium Lie said in 2005 "We will also see a bunch of microformats being developed, and that’s how the semantic web will be built, I believe."[23] However, in August 2008 Toby Inkster, author of the "Swignition" (formerly "Cognition") microformat parsing service, pointed out that no new microformat specifications had been published since 2005.[24]

Microformats2 was proposed and discussed during FOOEast, 2010-05-02.[28] Microformats2 was intended to make it easier for authors to publish microformats and for developers to consume them, while remaining backwards compatible[29]

Using microformats2, the example above would be marked up as:

The birds roosted at
   <span class="h-geo geo">
     <span class="p-latitude latitude">52.48</span>,
     <span class="p-longitude longitude">-1.89</span>
   </span>

and:

 <ul class="h-card vcard">
   <li class="p-name fn">Joe Doe</li>
   <li class="p-org org">The Example Company</li>
   <li class="p-tel tel">604-555-1234</li>
   <li><a class="u-url url" href="http://example.com/">http://example.com/</a></li>
 </ul>

• COinS
• Embedded RDF
• Intelligent agents
• RDFa Lite
• JSON-LD
• S5 (file format)
• Schema.org
• Simple HTML Ontology Extensions
• XMDP

• Suda, Brian (September 2006). Using Microformats. O'Reilly Media. p. 45. ISBN 978-0-596-52821-8.
• Ahmet Soylu, Patrick De Causmaecker, Fridolin Wild Ubiquitous Web for Ubiquitous Environments: The Role of Embedded Semantics, article in Journal of Mobile Multimedia, Vol. 6, No.1, pp. 26–48, (2010). PDF

Wikimedia Commons has media related to Microformat screenshots.

• microformats.org
• Microformats Primer
• Optimus microformats parser and validator
• A four-part discussion of Microformats, UI issues, and possible presentation in Firefox 3 by Alex Faaborg of Mozilla