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
div Tags which have no effect on the Presentation of the HTML Content.
classAttribute in HTML Tags (most times
<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
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].
<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> </span> Tel. <span class="tel">004915253306032</span> <img class="Photo" src="http://dgallery.s3.amazonaws.com/daniel_peace.jpg" />] </div>
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