Microformats

Microformats (μF) are predefined HTML markup (like HTML classes) created to serve as descriptive and consistent metadata about elements, designating them as representing a certain type of data (such as contact information, geographic coordinates, events, products, recipes, etc.). They allow software to process the information reliably by having set classes refer to a specific type of data rather than being arbitrary.

nofollow is a setting on a web page hyperlink that directs search engines not to use the link for page ranking calculations. It is specified in the page as a type of link relation; that is: <a rel="nofollow" ...>. Because search engines often calculate a site's importance according to the number of hyperlinks from other sites, the nofollow setting allows website authors to indicate that the presence of a link is not an endorsement of the target site's importance.

hCard is a microformat for publishing the contact details (which might be no more than the name) of people, companies, organizations, and places, in HTML, Atom, RSS, or arbitrary XML. The hCard microformat does this using a 1:1 representation of vCard (RFC 2426) properties and values, identified using HTML classes and rel attributes.

hCalendar (short for HTML iCalendar) is a microformat standard for displaying a semantic (X)HTML representation of iCalendar-format calendar information about an event, on web pages, using HTML classes and rel attributes.

HTML microformat developed in 2003

Microformat to create metadata for location properties

thumb | right | alt=A window of a referrer is open on a wikipedia article using citation templates with embedded COinS tags | An example of referrers acting on a Wikipedia article using citation templates with embedded COinS tags ContextObjects in Spans (COinS) is a method to embed bibliographic metadata in the HTML code of web pages. This allows bibliographic software to publish machine-readable bibliographic items and client reference management software to retrieve bibliographic metadata. The metadata can also be sent to an OpenURL resolver. This allows, for instance, searching for a copy o