<head profile="http://gmpg.org/xfn/11"> what is this?
From http://www.w3.org/TR/html401/struct/global.html#h-7.4.4.3
Meta data profiles
The profile attribute of the HEAD specifies the location of a meta data profile. The value of the profile attribute is a URI. User agents may use this URI in two ways: As a globally unique name. User agents may be able to recognize the name (without actually retrieving the profile) and perform some activity based on known conventions for that profile. For instance, search engines could provide an interface for searching through catalogs of HTML documents, where these documents all use the same profile for representing catalog entries. As a link. User agents may dereference the URI and perform some activity based on the actual definitions within the profile (e.g., authorize the usage of the profile within the current HTML document). This specification does not define formats for profiles.