Terminology

Agreement
An agreement is a small unit of information that is sufficient to indicate that both parties have agreed on a common proposal.

Assuring Party
P3P assumes the existence of an entity which assures that the service will abide by its proposal; this assurance may come from the service or an independent assuring party.   The assuring party digitally signs proposals and is responsible for assuring their implementation by the service.

Jim Miller

http://www.w3.org/