What is rich-snippets for people?
Marking up contact and social networking information in the body of a web page helps Google better recognize and display your information in search results.

Usage guidelines
Google recognizes the following contact properties, derived from the hCard microformat. (Where the microdata/RDFa and microformats property names differ, the microformats property name appears in parentheses.) Google also recognizes the XFN friend, contact, and acquaintance properties, which are used to identify social relationships