As defined in PLT.D of the JSR-168 specification, this class defines a set of
attribute names for user information and their intended
meaning. To allow portals an automated mapping of commonly used user information
attributes portlet programmers should use these attribute names. These attribute names
are derived from the Platform for Privacy Preferences 1.0 (P3P 1.0) Specification by the
W3C (http://www.w3c.org/TR/P3P).