Dion Hinchcliffe writes:
Information is often the most useful in bite-sized pieces. Storing information in convenient, tidy bundles sometimes called microcontent is still uncommon but this is changing quickly. Indeed, Web 2.0 trends will only increase the popularity of microformats that support discrete bits of lightly formatted information. This is one reason why Web 2.0 concepts strongly encourage small pieces, loosely joined: Monolithic specifications generally make for information that’s trapped inert behind large, hard to consume, and brittle walls of formatting. Microformats seek to add just enough structure to make the information easy to create and use as well as eminently repurposable.
So what microformats exist today? Quite few, and they really are tiny. Many of them are nothing more than an attribute added to an existing HTML tag. The quintessential microformat is XFN, the people relationships metadata profile. It specifies that you add information to a rel attribute in your anchor tags so that your relationships with those you link to on the Web can be provided. It helps increase sense of community on the Web and allows people to build tools that leverage this information, such as RubHub, an XFN relationships lookup engine.