From MozillaZine Knowledge Base
P3P (The Platform for Privacy Preferences) is a W3C recommendation that allows users to specify how they wish to accept cookies based on how a website says it will use them. This preference controls the browser's P3P handling.
Possible values and their effects
See network.cookie.p3p for an explanation of these values.
Low - afafaaaa
Medium - ffffaaaa (Default)
High - frfradaa
Custom - use the value in network.cookie.p3p
First checked in
Has an effect in