Public to the world. Public data is available to anyone who can see you in their system. Unless you alter the defaults, no data is by-default public. Any data located outside of a facet is public.

Searchable and Comparable. Profile data that might be used to lookup a person (i.e. an email address, IM account or name) is searchale in addition to being comparable.

Comparable. Profile data that is used for signal comparison (such as email address and interests) is by-default comparison. For example, when an email address is comparable, the system uses the domain name to determine a group of similar people. Interest data that is comparable is only shown to others who have matching interests.

Private/Facet access. Any information that is placed within a facet is available to the people who have access to that facet, but otherwise is considered private.

Private. Private data is available to no one, except you. Notes on individuals, facets and data are private.