Created on March 26, 2013, 1:18 p.m. by Hevok & updated by Hevok on May 2, 2013, 5:21 p.m.

Microformats are domain-specific Metadata that one can put into HTML pages. Microformats are around for quite a while. It is HMTL or (X)HTML Markup to express limited Semantics which has been defined in an informal way within a HTML Document. It is designed to solve simple and specific problems. In the first place it is designed for Humans and only in the second Place for Machines, but it can be parsed easily out of the HTML document. It is used in Web Pages to describe specific types of Information (e.g. Persons, events, products, reviews, and so on). There are lot of Applications around that can easily extract this Data from HTML Documents. In general it works on specific Tags or Attributes within HTML Texts, so that one does not sees the Microformats at all. They work in the class Attribute for example as well as in span or div Tags which have no effect on the Presentation of the HTML Content.

  • Microformats (╬╝formats) emerged about 2005
  • (X)HTML Markup to express (limited) Semantics in an HTML Document
    • Designed to solve simple, specific problems
    • Designed for humans first, machines second
    • Used in Web Pages to describe a specific type of Information, as e.g. Person, an Event, a Product, a Review, etc.
  • Applications can easily extract data from HTML Documents
  • In general, Mciroformats use the class Attribute in HTML Tags (most times <span> or <div> Tags) and assign brief and descriptive names to Entities and their properties.

In general Microformats are put into HTML Documents by reusing HTML Tag attributes like class, rel or rev. There are number of predifined Microformats. There are a number of predifined Microformats. Which Microformats are available can be found at [http://microformats.org].

  • Microformats reuse te following (X)HTML Tag Attributes:
    • class
    • rel
    • rev
  • Predifined standard Microformats:
    • hCard - Person Data (vCard, RFC2426)
    • hCalender - Calendars and Events
    • rel-Tag - Tags, Keywords, Categories
    • XFN - XHTML Friend Network
    • hReview, VoteLinks`` -- Opinions, Ratings, and Review
    • XOXO - Lists and Outlines
    • ...
  • [http://microformats.org]
    <div class="vard">
        <span class="fn">Daniel Wuttke</span>
        <span class="title">MPhil"</span>
        <span class="org">Denigma Organization</span>
        <span class="adr">
            <span class="street-address">Hunsrueckstrasse 11, </span>
            <span class="postal-code">45968</span>
            <span class="locality">Gladbeck</span>
        Tel. <span class="tel">004915253306032</span>
        <img class="Photo" src="http://dgallery.s3.amazonaws.com/daniel_peace.jpg" />]

The Meaning of all these Properties is described in the Microformat Website in an informal way, i.e. Natural Language.

From this data one can not deduce in an automated way what it really means, so the Semantics is given in an informal way as it is simple structured Data and not real Semantic Data on the Web.

As it is structured Data one can transcode or translate it into RDF and one can do this also in an automated way for instance by using XML stylesheets.

The Trouble with Microformats is when one wants to introduce new Microformats first they have to be consolidated by the communities, because it always takes a new XML Stylesheet that has to be developed for the extraction of this Metadata. On the other hand if one uses more than one of these Microformats Vocabularies within a single (X)HTML Document, then the processing Complexity will be much more complicated because one has to distinguish which property or which Property or which Attribute belongs to which Vocabulary and this might get rather complicated. Conflicts might arise with the used (X)HTML Attributes.

With Microformats one is restricted to a specific Domain, so it is rather restrictive, while with RDF one can formulate any kind of Knowledge. Although in RDF there are also several Restrictions within it, but one can encode for example also OWL Ontologies. For this Reason there exists RDFa

  • Microformats can easily be transcoded to RDF via XSLT
  • New Microformat Vocabularies One first must be consolidated by the Community, while always e new XSLT Stylesheet has to be developed for extraction
  • By using more than on Microformat Vocabulary in a single (X)HTML Document the processing complexity increases rapidly
  • Conflicts with used (X)HTML Attributes might be possible

Tags: web, encoding, metadata, format
Categories: Concept
Parent: Semantic Metadata

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