Microformat 17
Microformat
A microformat (sometimes abbreviated μF) is a web-based approach to semantic markup which seeks to re-use
existing HTML/XHTML tags to convey metadata[1] and other attributes in web pages and other contexts that support
(X)HTML, such as RSS. This approach allows software to process information intended for end-users (such as
contact information, geographic coordinates, calendar events, and the like) automatically.
Although the content of web pages is technically already capable of "automated processing", and has been since the
inception of the web, such processing is difficult because the traditional markup tags used to display information on
the web do not describe what the information means.[2] Microformats can bridge this gap by attaching semantics, and
thereby obviate other, more complicated, methods of automated processing, such as natural language processing or
screen scraping. The use, adoption and processing of microformats enables data items to be indexed, searched for,
saved or cross-referenced, so that information can be reused or combined.[2]
As of 2010, microformats allow the encoding and extraction of events, contact information, social relationships and
so on. While more are still being developed, it appears that other formats such as schema.org have achieved greater
industry support.[3]Background
Microformats emerged 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.[2][4] Link-based microformats emerged first. These include vote links that express opinions of the linked
page, which search engines can tally into instant polls.[5]
As the microformats community grew, CommerceNet, a nonprofit organization that promotes electronic commerce
on the Internet, helped sponsor and promote the technology and support the microformats community in various
ways.[5] CommerceNet also helped co-found the Microformats.org community site.[5]
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.[5] Most of the existing microformats
were created 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.Technical overview
XHTML and HTML standards allow for the embedding and encoding of semantics within the attributes of markup
tags. 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[6])
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