<abbr title="XHTML Friends Network">XFN™</abbr> (<strong>X</strong>HTML <strong>F</strong>riends <strong>N</strong>etwork) is a simple way to represent human relationships using hyperlinks. In recent years, <dfn><a href="http://www.technorati.com/help/blogging101.html" title="Hyperlink to a definition of the term 'blog' and related terms.">blogs</a></dfn> and <dfn><a href="http://www.microcontentnews.com/resources/glossary/blogrolling.htm" title="Hyperlink to a definition of the term 'blogrolling'">blogrolls</a></dfn> have become the fastest growing area of the Web. XFN enables web authors to indicate their relationship(s) to the people in their blogrolls simply by adding a '<code>rel</code>' attribute to their <code title="hyperlink anchor"><a href></code> tags, e.g.:
