How does it work? Through XHTML Friends Network (XFN) & Friend of a Friend (FOAF), the Social Graph API looks for relationships between web properties, whether you control that relationship or not. rel=”me”, amongst other microformats, are added to any hyperlink where you wish to indicate a relationship. You can set how the link is related to you (co-worker link, friendship, parent, child, etc.) You can even create your own mix.