Categories: controlinformprovide

Policy Matching Display


Give one careful thought to your privacy needs, then be always able to swiftly apply what you decided.


A user wants to start using a new service, which lets the user configure several privacy-related parameters. The user often does the same with new, different service providers.


Users may get overwhelmed by the burden of deciding on privacy aspects each and every time they enrol in a new service. This may make them err on their decisions regarding privacy.


Before contracting a service, the service provider retrieves the user preferences (exposed by their user agent, or at a well-known URI), and presents the user a comparison between their preferences and the privacy policies applied by default by the service operator, which in turn automatically adapts any configurable values to the user’s declared preferences.

Allow users to provide a consistent privacy-related behaviour, while reducing their cognitive workload every time they enrol in a new service.


This pattern requires sharing a machine-readable format to express and exchange definitions of privacy policies between the user agent and the service providers. Several such formats exist, yet they are not always supported by either user agents or by service providers. Besides, not all the privacy policy nuances can be expressed in existing privacy policy languages.

[Known Uses]

  • For an academic discussion, see Graf, C., Wolkerstorfer, P., Geven, A., & Tscheligi, M. (2010, November). A pattern collection for privacy enhancing technology. In PATTERNS 2010, The Second International Conferences on Pervasive Patterns and Applications (pp. 72-77).
  • For a discussion of privacy languages see Kumaraguru, P., Cranor, L., Lobo, J., & Calo, S. (2007, July). A survey of privacy policy languages In SOUPS'07: Proceedings of the 3rd Symposium on Usable Privacy and Security. and Becker, M. Y., Malkis, A., & Bussard, L. (2010).
  • A related, classic initiative was W3C's The Platform for Privacy Preferences 1.1 (P3P1.1) Specification, however, the matching was performed at the client's side.
  • A more recent example is available at S4P: A generic language for specifying privacy preferences and policies. Microsoft Research.
  • ... and Sacco, O., & Passant, A. (2011, March). A Privacy Preference Ontology (PPO) for Linked Data. In LDOW.