Mobile Location Services: The Definitive Guide

2. Referencing Policies

2.1. Overview and Purpose of Policy References

Locating a P3P policy is one of the first steps in the operation of the P3P protocol. Services use policy references to state what policy applies to a specific URI or set of URIs. User agents use policy references to locate the privacy policy that applies to a page, so that they can process that policy for the benefit of their user.

Policy references are used extensively as a performance optimization. P3P policies are typically several kilobytes of data, while a URI that references a privacy policy is typically less than 100 bytes. In addition to the bandwidth savings, policy references also reduce the need for computation: policies can be uniquely associated with URIs, so ...