The Platform for Privacy Preferences 1.0 (P3P1.0) Specification

W3C Working Draft 24 April 2000

This Version:: http://www.w3.org/TR/2000/WD-P3P-20000424
Latest Version:: http://www.w3.org/TR/P3P
Previous Version:: http://www.w3.org/TR/2000/WD-P3P-20000404
Editor:: Massimo Marchiori, W3C/MIT, (massimo@w3.org)
Authors:: Lorrie Cranor, AT&T; Marc Langheinrich, ETH Zurich; Massimo Marchiori, W3C/MIT
Martin Presler-Marshall, IBM; Joseph Reagle, W3C/MIT

Abstract

This is the specification of the Platform for Privacy Preferences (P3P). This document, along with its normative references, includes all the specification necessary for the implementation of interoperable P3P applications.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. The latest status of this document series is maintained at the W3C.

This is a W3C Working Draft for review by W3C members and other interested parties. This document has been produced by the P3P Specification Working Group as part of the P3P Activity, and it is the third revision of the last call draft issued the 2nd of November 1999 (http://www.w3.org/TR/1999/WD-P3P-19991102). A change log is included at the end of this document for convenience. The last call period is expected to end on April 30, 2000. A revised version of this specification is expected to advance toward W3C Recommendation status after two interoperable implementations have been demonstrated.

This Working Draft includes an extension mechanism that can be used to extend the P3P vocabulary. The Working Group is particularly interested in feedback on how to improve this mechanism as well as examples of extensions that people would like to propose. These examples may be useful for improving the design of the extension mechanism. In addition, the Working Group may consider incorporating some of these ideas into the P3P vocabulary so that they need not be introduced later as extensions. The introduction to this document (Section 1) provides additional information about the status of this working draft and future versions of P3P.

While this document is in last call, it is still a draft document that may be updated, replaced, or obsoleted by other documents at any time. It is therefore inappropriate to use W3C Working Drafts as reference material or to cite them as other than "work in progress." A list of current W3C working drafts can be found at http://www.w3.org/TR/.

Please send comments to www-p3p-public-comments@w3.org (archived at http://lists.w3.org/Archives/Public/www-p3p-public-comments/).

Introduction
Referencing Policies
Policy Syntax and Semantics
Data Schemas
Appendices
Appendix 1: References (Normative)
Appendix 2: References (Non-normative)
Appendix 3: The P3P Base Data Schema Definition (Normative)
Appendix 4: XML Schema Definitions (Normative)
Appendix 5: XML DTD Definition (Normative)
Appendix 6: RDF Data Model (Non-normative)
Appendix 7: ABNF Notation (Non-normative)
Appendix 8: P3P Guiding Principles (Non-normative)
Appendix 9: Working Group Contributors (Non-normative)

1. Introduction

The Platform for Privacy Preferences Project (P3P) enables Web sites to express their privacy practices in a standard format that can be retrieved automatically and interpreted easily by user agents. P3P user agents will allow users to be informed of site practices (in both machine- and human-readable formats) and to automate decision-making based on these practices when appropriate. Thus users need not read the privacy policies at every site they visit.

Although P3P provides a technical mechanism for ensuring that users can be informed about privacy policies before they release personal information, it does not provide a technical mechanism for making sure sites act according to their policies. Products implementing this specification MAY provide some assistance in that regard, but that is up to specific implementations and outside the scope of this specification. However, P3P is complementary to laws and self-regulatory programs that can provide enforcement mechanisms. In addition, P3P does not include mechanisms for transferring data or for securing personal data in transit or storage. P3P may be built into tools designed to facilitate data transfer. These tools should include appropriate security safeguards.

1.1 The P3P1.0 Specification

The P3P1.0 specification defines the syntax and semantics of P3P privacy policies, and the mechanisms for associating policies with Web resources. P3P policies consist of statements made using the P3P vocabulary for expressing privacy practices. P3P policies also reference elements of the P3P base data schema -- a standard set of data elements that all P3P user agents should be aware of. The P3P specification includes a mechanism for defining new data elements and data sets, and a simple mechanism that allows for extensions to the P3P vocabulary.

1.1.1 Goals and Capabilities of P3P 1.0

P3P version 1.0 is a protocol designed to inform Web users of the data-collection practices of Web sites. It provides a way for a Web site to encode its data-collection and data-use practices in a machine-readable XML format known as a P3P policy. The P3P specification defines:

A standard schema for data a Web site may wish to collect, known as the "P3P base data schema"
A standard set of uses, recipients, data categories, and other privacy disclosures
An XML format for expressing a privacy policy
A means of associating privacy policies with Web pages or sites
A mechanism for transporting P3P policies over HTTP

The goal of P3P version 1.0 is twofold. First, it allows Web sites to present their data-collection practices in a standardized, machine-readable, easy-to-locate manner. Second, it enables Web users to understand what data will be collected by sites they visit, how that data will be used, and what data/uses they may "opt-out" of or "opt-in" to.

1.1.2 Example of P3P in Use

As an introduction to P3P, let us consider one common scenario which makes use of P3P. Sheila has decided to check out a store called CatalogExample, located at http://www.catalog.example.com/. Let us assume that CatalogExample has placed P3P policies on all their pages, and that Sheila is using a Web browser with P3P built in.

Sheila types the address for CatalogExample into her Web browser. When CatalogExample's server returns their homepage, it also returns the P3P privacy policy which applies to that page. The policy states that the only data the site collects on its home page is the data found in standard HTTP access logs. Now Sheila's Web browser checks this policy against the preferences Sheila has given it. Is this policy acceptable to her, or should she be notified? Let's assume that Sheila has told her browser that this is acceptable. In this case, the homepage is displayed normally, with no pop-up messages appearing. Perhaps her browser displays a small icon somewhere along the edge of its window to tell her that a privacy policy was given by the site, and that it matched her preferences.

Next, Sheila clicks on a link to the site's online catalog. The catalog section of the site has some more complex software behind it. This software uses cookies to implement a "shopping cart" feature. Since more information is being gathered in this section of the web site, the Web server sends a new P3P policy to Sheila's browser. Again, let's assume that this policy matches Sheila's preferences, so she gets no pop-up messages. Sheila continues and selects a few items she wishes to purchase. Then she proceeds to the checkout page.

The checkout page of CatalogExample requires some additional information: Sheila's name, address, credit card number, and telephone number. The web site sends a new P3P policy that describes the data that is collected here and states that her data will be used only for completing the current transaction, her order.

Sheila's browser examines this P3P policy. Imagine that Sheila has told her browser that she wants to be warned whenever a site asks for her phone number. In this case, the browser will pop up a message saying that this Web site is asking for her phone number, and then explains the contents of the P3P statement. Sheila can then decide if this is acceptable to her. If it is acceptable, she can continue with her order; otherwise she can cancel the transaction.

Alternatively, Sheila could have told her browser that she wanted to be warned only if a site is asking for her telephone number and was going to give it to third parties and/or use it for uses other than completing the current transaction. In that case, she would have received no prompts from her browser at all, and she could proceed with completing her order.

Note that this scenario describes one hypothetical implementation of P3P. Other types of user interfaces are also possible.

1.1.3 P3P Policies

P3P policies use an XML encoding of the P3P vocabulary to identify the legal entity making the representation of privacy practices in a policy, enumerate the types of data or data elements collected, and explain how the data will be used. In addition, policies identify the data recipients, and make a variety of other disclosures including information about dispute resolution, and the address of a site's human-readable privacy policy. P3P policies must cover all relevant data elements and practices (but note that legal issues regarding law enforcement demands for information are not addressed by this specification; it is possible that a site that otherwise abides by its policy of not redistributing data to others may be required to do so by force of law). P3P declarations are positive, meaning that sites state what they do, rather than what they do not do. The P3P vocabulary is designed to be descriptive of a site's practices rather than simply an indicator of compliance with a particular law or code of conduct. However, user agents may be developed that can test whether a site's practices are compliant with a law or code.

P3P policies represent the practices of the site. Intermediaries such as telecommunication providers, Internet service providers, proxies and others may be privy to the exchange of data between a site and a user, but their practices may not be governed by the site's policies.

1.1.4 P3P User Agents

P3P1.0 user agents can be built into web browsers, browser plug-ins, or proxy servers. They can also be implemented as Java applets or JavaScript; or built into electronic wallets, automatic form-fillers, or other user data management tools. P3P user agents look for P3P headers in HTTP responses and in P3P META tags embedded in HTML content. These special headers and tags indicate the location of a relevant P3P policy. User agents can fetch the policy from the indicated location, parse it, and display symbols, play sounds, or generate user prompts that reflect a site's P3P privacy practices. They can also compare P3P policies with privacy preferences set by the user and take appropriate actions. P3P can perform a sort of "gate keeper" function for data transfer mechanisms such as electronic wallets and automatic form fillers. A P3P user agent integrated into one of these mechanisms would retrieve P3P policies, compare them with user's preferences, and authorize the release of data only if a) the policy is consistent with the user's preferences and b) the requested data transfer is consistent with the policy. If one of these conditions is not met, the user might be informed of the discrepancy and given an opportunity to authorize the data release themselves.

1.1.5 Implementing P3P1.0 on Servers

Web sites can implement P3P1.0 on their servers by translating their human-readable privacy policies into P3P syntax and configuring their servers to advertise the location of the P3P policy. Automated tools can assist sites in performing this translation. Many HTTP1.1 servers can be configured to support P3P1.0 without requiring the installation of additional software. Servers may be configured to insert a P3P extension header into all HTTP responses that indicates the location of a site's P3P policy, using the HTTP Extension Framework. Alternatively, they can be configured to insert this information into HTML content as a META tag. Web sites have some flexibility in how they use P3P: they can opt for one P3P policy for their entire site or they can designate different policies for different parts of their sites. A P3P policy MUST cover all data generated or exchanged as part of a site's HTTP interactions with visitors. In addition, some sites may wish to write policies that cover all data an entity collects, regardless of how the data is collected.

1.1.6 Future Versions of P3P

The P3P Specification Working Group removed significant sections from earlier drafts of the P3P1.0 specification in order to facilitate rapid implementation and deployment of a P3P first step. The group envisions the release of future versions of the P3P specification after P3P1.0 is deployed. This specification would likely include improvements based on feedback from implementation and deployment experience as well as four major components that were part of the original P3P vision but not included in P3P1.0:

a mechanism to allow sites to offer a choice of P3P policies to visitors
a mechanism to allow visitors (through their user agents) to explicitly agree to a P3P policy
mechanisms to allow for non-repudiation of agreements between visitors and web sites
a mechanism to allow user agents to transfer user data to services

1.2 About this Specification

This document, along with its normative references, includes all the specification necessary for the implementation of interoperable P3P applications.

The [ABNF] notation used in this specification is specified in RFC2234 and summarized in Appendix 7. However, note that such syntax is only a grammar representative of the XML syntax: all the syntactic flexibilities of XML are also implicitly included; e.g. whitespace rules, quoting using either single quote (') or double quote ("), character escaping, comments, case sensitivity, order of attributes.

The following key words are used throughout the document and should be read as interoperability requirements. This specification uses words as defined in RFC2119 [KEY] for defining the significance of each particular requirement. These words are:

MUST or MUST NOT: This word or the adjective "required" means that the item is an absolute requirement of the specification.
SHOULD or SHOULD NOT: This word or the adjective "recommended" means that there may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood and the case carefully weighed before choosing a different course.
MAY: This word or the adjective "optional" means that this item is truly optional. One vendor may choose to include the item because a particular marketplace requires it or because it enhances the product, for example; another vendor may omit the same item.

1.3 Terminology

Data Element: An individual data entity, such as last name or telephone number. For interoperability, P3P1.0 specifies a base set of data elements.
Data Category: A significant attribute of a data element or data set that may be used by a trust engine to determine what type of element is under discussion, such as physical contact information. P3P1.0 specifies base data categories.
Data Set: A known grouping of data elements, such as "user.home.postal.". A set is represented with a trailing period. P3P1.0 specifies a number of base data schemas.
Equable Practice: A practice that is very similar to another in that the purpose, recipients, and identifiable use are the same or more constrained than the original, and the other disclosures are not substantially different. For example, two sites with otherwise similar practices that follow different -- but similar -- sets of industry guidelines.
Personally Identifiable Data: Any information relating to an identified or identifiable individual.
Policy: A collection of one or more privacy statements together with information asserting the identity, URI, assurances, and dispute resolution procedures of the service covered by the policy.
Practice: The set of disclosures regarding data usage, including purpose, recipients, and other disclosures.
Preference: A rule, or set of rules, that determines what action(s) a user agent will take. A preference might be expressed as a formally defined computable statement (e.g., the [APPEL] preference exchange language).
Purpose: The reason(s) for data collection and use.
Repository: A mechanism for storing user information under the control of the user agent.
Service: A program that issues policies and (possibly) data requests. By this definition, a service may be a server (site), a local application, a piece of locally active code, such as an ActiveX control or Java applet, or even another user agent.
Service Provider (Data Controller, Legal Entity): The person or legal entity which offers information, products or services from a Web site, collects information, and is responsible for the representations made in a practice statement.
Statement: A P3P statement is a set of privacy practice disclosures relevant to a collection of data elements.
URI: A Uniform Resource Identifier used to identify Web resources. For definitive information on URI syntax and semantics, see [URI].
User: An individual (or group of individuals acting as a single entity) on whose behalf a service is accessed and for which personal data exists.
User Agent: A program whose purpose is to mediate interactions with services on behalf of the user under the user's preferences. A user may have more than one user agent, and agents need not reside on the user's desktop, but any agent must be controlled by and act on behalf of only the user. The trust relationship between a user and her agent may be governed by constraints outside of P3P. For instance, an agent may be trusted as a part of the user's operating system or Web client, or as a part of the terms and conditions of an ISP or privacy proxy.

2. Referencing Policies

2.1 Overview and Purpose of Policy References

Referencing 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 will use policy references to locate the privacy policy which applies to a page, so that they can process that policy for the benefit of their user.

Policy references are extensively as a performance optimization. Privacy policies are typically several kilobytes of data, while a URI which references a privacy policy is typically less than 50 bytes. In addition to the bandwidth savings, policy references also reduce the need for computation: policies can be uniquely associated with URIs, so that a user agent need only parse and process a policy once rather than process it with every document to which the policy applies. Furthermore, by placing the information about relevant policies in a centralized location, Web site administration is simplified.

2.1.1 Mechanisms

A policy reference file is used to associate a policy with a URI. The location of the policy reference file can be indicated using one of two mechanisms. This can be done through an HTML LINK tag, or through the HTTP Extension Framework. The policy reference file specifies the P3P policy that applies to that document. The policy reference file is an [RDF]/[XML] file that can specify the policy for a single Web document, portions of a Web site, or for an entire site. The policy reference file may refer to one or more P3P policies; this allows for a single reference file to cover an entire site, even if different P3P policies apply to different portions of the site.

Note that policies are applied at the level of HTTP entities. An entity, retrieved by fetching a URI, has a P3P policy associated with it. A "page" from the user's perspective may be composed of multiple HTTP entities; each entity may have its own P3P policy associated with it. As a practical note, however, placing many different P3P policies on different entities on a single page may make rendering the page and informing the user of the relevant policies difficult for user agents. Additionally, services SHOULD attempt to craft their policy reference files such that a single policy reference file covers any given "page"; this will speed up the user's browsing experience.

This document does not specify how P3P policies may be associated with documents retrieved by means other than HTTP.

2.2 Policy Reference Syntax

This section describes the syntax used to make policy references using the two supported mechanisms.

2.2.1 Syntax Using HTTP Extension Framework

P3P makes use of the HTTP Extension Framework [HTTP-EXT]. The HTTP Extension Framework allows new HTTP headers to be defined and used. All HTTP headers associated with a given extension in a request or response are to be prefixed by an arbitrary two-digit namespace identifier. This prefix may be chosen by implementations on a per-message basis. This guarantees a unique namespace for the extension's headers. In addition, the extension must identify itself (with a URI) when it declares the namespace.

2.2.1.1 Use of the HTTP Extension Framework

The HTTP Extension Framework requires a globally unique URI identifying the extension (the extension declaration). The P3P extension declaration is the following URI:

http://www.w3.org/2000/P3Pv1

Any document retrieved by HTTP may point to a policy reference file through the use of a new response header, the PolicyRef header. The PolicyRef header contains the URI of a policy reference file, which will state the P3P policy covering the document that pointed to the reference file, and possibly others as well. This URI MUST NOT be used for any other purpose beyond identifying and referencing P3P policies.

The P3P extension declaration and policy header SHOULD be inserted whenever a P3P-enabled server responds to a relevant request, including when it responds to HEAD and OPTIONS requests.

As it is possible for non-P3P-enabled user agents to properly interpret and process responses which include the P3P policy reference, P3P is an "optional" extension in the terms of the HTTP Extension Framework. Since policy references may be processed by agents anywhere along the response chain, P3P is an end-to-end HTTP extension. Thus, the header used to declare the P3P extension will be Opt.

2.2.1.2 Header Syntax

The header syntax is:

[1]
policy-reference-header

=

nsprefix `-PolicyRef: ` URI

Here, URI is defined as per RFC 2396 [URI]. nsprefix is the two-digit namespace declaration selected for the P3P headers in this message, according to [HTTP-EXT]. It may be any two-digit number that does not conflict with other namespace declarations in the response.

In keeping with the rules for other HTTP headers, the PolicyRef portion of this header may be written in any case.

Example 2.1:

1. Client makes a GET request.

GET /index.html HTTP/1.1
Host: catalog.example.com
Accept: */*
Accept-Language: de, en
User-Agent: WonderBrowser/5.2 (RT-11)

2. Server returns content and the PolicyRef header pointing to the policy of the page.

HTTP/1.1 200 OK
Opt: "http://www.w3.org/2000/P3Pv1"; ns=11
11-PolicyRef: http://catalog.example.com/P3P/PolicyReferences.xml
Content-Type: text/html
Content-Length: 7413
Server: CC-Galaxy/1.3.18

2.2.2 Syntax Using the `link` Tag

Servers may serve HTML content with embedded link tags that indicate the location of the relevant P3P policy reference file. This use of P3P does not require a P3P-aware server; content may be modified to include the embedded link tags without requiring any changes to the way the server operates.

The link tag encodes the information that could be expressed using the P3P PolicyRef header. The link tag takes the following form:

[2]
p3p-link-tag

=

`<link rel="P3Pv1" href="` URI `">``

Here, URI is defined as per RFC 2396 [URI].

For example, the policy reference expressed in Example 2.1 using HTTP headers could be expressed equally well by including in the web page http://catalog.example.com/index.html the following piece of HTML:

<link rel="P3Pv1" 
    href="http://catalog.example.com/P3P/PolicyReferences.xml">

Note that if user agents handle HTML, they MUST handle both mechanisms (policy references in HTTP headers or in link tags) interchangeably; neither of the two mechanisms overrides the other. See also the requirements for non-ambiguity.

2.3 Policy Reference File Syntax and Semantics

A policy reference file is used to associate P3P policies with certain regions of URI-space. Regardless of the mechanism documents use to link to a policy reference file, the syntax of that reference file remains the same. The policy reference file is used to make any or all of the following statements:

The URI where a P3P policy is found
The URIs or regions of URI-space covered by this policy
The URIs or regions of URI-space not covered by this policy
The access methods for which this policy is applicable
The period of time for which those claims are considered to be valid

The first four statements are made in the body of the policy reference file. The last is made using HTTP expiration headers on the policy reference file.

2.3.1 Example Policy Reference File

Consider the case of a Web site wishing to make the following statements:

P3P policy /P3P/Policy1.p3p applies to the entire site, except the subtrees /catalog, /cgi-bin, and /servlet.
P3P policy /P3P/Policy2.p3p applies to all documents in the /catalog directory (and its subdirectories).
P3P policy /P3P/Policy3.p3p applies to all documents in the /cgi-bin and /servlet directories (and their subdirectories), except for /servlet/unknown.
No statement is made about what P3P policy applies to /servlet/unknown.
These statements are valid for 8 hours.

These statements could be represented by the following [RDF]:

Example 2.2:

<POLICY-REFERENCES
    xmlns="http://www.w3.org/2000/P3Pv1"
    xmlns:web="http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
  <web:RDF>

    <POLICY-REF web:about="/P3P/Policy1.p3p">
      <PREFIX>/</PREFIX>
      <EXCLUDE>/catalog/</EXCLUDE>
      <EXCLUDE>/cgi-bin/</EXCLUDE>
      <EXCLUDE>/servlet/</EXCLUDE>
    </POLICY-REF>

    <POLICY-REF web:about="/P3P/Policy2.p3p">
      <PREFIX>/catalog/</PREFIX>
    </POLICY-REF>

    <POLICY-REF web:about="/P3P/Policy3.p3p">
      <PREFIX>/cgi-bin/</PREFIX>
      <PREFIX>/servlet/</PREFIX>
      <EXCLUDE>/servlet/unknown</EXCLUDE>
    </POLICY-REF>

  </web:RDF>
</POLICY-REFERENCES>

To indicate that the claims made by this policy reference file are good for 8 hours, the origin server serving this page would return a Cache-Control: max-age=28800 header with this file. Alternatively, the origin server could generate an Expires header dated 8 hours past the Date header in the response.

2.3.2 Policy Reference File Definition

This section defines the syntax and semantics of P3P policy reference files. All policies MUST be encoded using [UTF-8]. P3P servers MUST encode their policy references using this syntax. P3P user agents MUST be able to parse this syntax.

One significant point to make about the syntax of policy reference files is that the syntax defined here does not have an extension mechanism. The syntax for P3P policies has a powerful extension mechanism, but that mechanism is not supported for policy reference files.

2.3.2.1 Policy Reference File Lifetimes

The lifetime of a policy reference file tells user agents how long they can rely on the claims made in the reference file. For example, if a policy reference file has a lifetime of 16 hours, then a user agent need not reload that file for 16 hours, and can assume that the references made in that reference file are good for 16 hours. All of the policy references made in a single policy reference file will receive the same lifetime. The only way to specify different lifetimes for P3P policies is to use separate policy reference files for each policy.

The lifetime of a policy reference file is determined by the HTTP cache control headers served with the reference file. However, user agents MUST NOT use heuristic expiration based on last-modified to compute a lifetime for the reference file. User agents MUST compute a lifetime for the policy reference file based on Expires, Cache-Control, or Pragma headers served with the file if they are available. The semantics of these headers are defined by [HTTP]. If none of these headers is available, the lifetime MUST be set to 24 hours from the time the document was sent from the origin server. Origin servers SHOULD use one of the headers listed above to give an explicit lifetime for their policy reference files.

The possible presence of caches in the network and the heuristic expiration mechanism in HTTP considerably complicates lifetime considerations. Consider the case of policy reference files which have no explicit cache lifetime defined by the origin server (i.e., none of the headers listed above are included in the response). A network caches will, in all likelihood, compute a cache lifetime for the policy reference file based on its last-modified date; the resulting cache lifetime could be significantly longer that 24 hours. If a user agent then retrieves this policy reference file from an HTTP 1.0 cache, the user agent has no way to know how long the reference file may have been in the cache. It would then be impossible for the user agent to determine if the reference file's lifetime has already expired, or when it will expire. HTTP 1.1 caches improve the situation somewhat, as HTTP 1.1-compliant caches MUST send an Age header when serving a request from their cache. However, even this is not sufficient; the cache could return a file with an age exceeding the 24-hour lifetime defined here, resulting in a useless policy reference file. To avoid these problems, user agents MUST insure that they load a fresh copy of the policy reference file when it is fetched. Thus, a user agent MUST include either a Pragma: no-cache or a Cache-Control: no-cache request-header when fetching a policy reference file. The former is suggested for compatability with HTTP 1.0 caches.

Note that it is impossible for a client to accurately predict the amount of latency that may affect an HTTP request. Thus, if the policy reference file covering a request is going to expire soon, clients MAY wish to consider warning their users and/or revalidating the policy reference file before continuing with the request.

2.3.2.2 The `POLICY-REFERENCES` element

The POLICY-REFERENCES element contains a complete policy reference file. Exactly one POLICY-REFERENCES element MUST be in a policy reference file. This element MUST contain one RDF element. It MAY optionally contain one or more extensions.

POLICY-REFERENCES: contains one RDF element. This element has no attributes.

[3]	policies	=	`<POLICY-REFERENCES xmlns="http://www.w3.org/2000/P3Pv1" ` rdf-ns-def `>` rdf `</POLICY>`
[4]	rdf-ns-def	=	xmlns `:` rdf-ns-prefix `="http://www.w3.org/1999/02/22-rdf-syntax-ns#"`
[5]	rdf-ns-prefix	=	NCName
Here `NCName` is defined in Namespaces in XML [Namespace]

2.3.2.3 The `RDF` element

The RDF element encapsulates RDF expressions in a policy reference file. This element MUST contain one or more POLICY-REF (policy reference) elements.

POLICY-REFERENCES: contains one or more discrete policy references. This element has no attributes.

[6]

rdf

`<` rdf-ns-prefix `:` `RDF>`
policy-ref
`</` rdf-ns-prefix `:` `RDF/>`

2.3.2.4 The `POLICY-REF` element

A policy reference file may refer to multiple P3P policies, specifying information about each. The POLICY-REF element is an RDF resourece, and describes attributes of a single P3P policy. Elements within the POLICY-REF element give the location of the policy and specify the areas of URI-space that each policy covers.

POLICY-REF: contains information about a single P3P policy.
(rdf-nf-prefix:)about (mandatory attribute): URI of the P3P policy. If this is a relative URI, it is interpreted relative to the URI of the policy reference file. This may be either a direct or an indirect policy reference; see Direct and Indirect Policy References for a definition of these terms.

[7]	policy-ref	=	`<POLICY-REF ` rdf-ns-prefix `:` `about="` URI `">` prefix exclude *method-element `</POLICY-REF>`
Here, `URI` is defined as per RFC 2396 [URI].

2.3.2.5 The `PREFIX` and `EXCLUDE` elements

Each PREFIX or EXCLUDE element specifies one local URI-prefix. They are used to specify the portions of the Web site that is covered by the policy mentioned by the enclosing POLICY-REF element.

When PREFIX (and optionally, EXCLUDE) elements are present in a POLICY-REF element, it means that the policy specified in the space attribute of the POLICY-REF element applies to all the URIs at the requested host corresponding to the local-URI(s) specified by the PREFIXes, but not specified by an EXCLUDE element.

If no PREFIX element is included in a POLICY-REF element, it MUST be implicitly assumed that the policy given by the href applies to the resource which linked to this policy reference file. It is an error for a policy reference file to contain two or more POLICY-REF elements without PREFIX elements. It is legal, but pointless, to supply an EXCLUDE element without any PREFIX elements; in that case, the EXCLUDE elements MUST be ignored by user agents.

A policy reference file can only cover URIs on the same host as the reference file. Therefore, the PREFIX and EXCLUDE elements MUST specify only local URI prefixes; they MUST NOT refer to URIs on other hosts. This requirement does NOT apply to the location of the P3P policy file (the href attribute on the POLICY-REF element).

Note that policy reference files do not support any sort of regular expressions. The only mechanism offered in a POLICY-REF element is to refer to the current document (implicitly, by not giving a PREFIX element), or to use a relative URI-prefix. It is not possible, for example, to state that a certain P3P policy applies to all URIs ending with the extension ".asp", or to any URIs containing more than 3 instances of the letter 't'. Additionally, a policy reference file MUST NOT make statements about URIs on hosts other than the one where the policy reference file is located.

Further, notice that PREFIX and EXCLUDE matching is done as a simple string prefix matching. As a result, a missing "/" at the end of a directory prefix might lead to unexpected results. For example, the element <EXCLUDE>/images/logos</EXCLUDE> (notice the missing '/' at the end of the href) will not only exclude all resources in the /images/logos/ subdirectory but also, for example, a file with the relative URI /images/logoschool.jpg!

[8]
prefix

=

`<PREFIX>` URI`</PREFIX>`

[9]
exclude

=

`<EXCLUDE>` URI `</EXCLUDE>`

Here, URI is defined as per RFC 2396 [URI].

2.3.2.5 The `METHOD` element

By default, a policy reference applies to the stated URIs regardless of the method used to access the resource. However, a Web site may wish to define different P3P policies depending on the method to be applied to a resource. For example, a site may wish to collect more data from users when they are performing PUT or DELETE methods than when performing GET methods.

The METHOD element in a policy reference file is used to state that the enclosing policy reference only applies when the specified methods are used to access the referenced resources. The METHOD element may be repeated to indicate multiple applicable methods. If the METHOD element is not present in a POLICY-REF element, then that POLICY-REF element covers the resources indicated regardless of the method used to access them.

So, to state that /P3P/Policy1.p3p applies to all documents in the subtree /docs/ for GET and HEAD methods, while /P3P/Policy2.p3p applies for PUT and DELETE methods, the following policy reference would be written:

Example 2.3:

<POLICY-REFERENCES
    xmlns="http://www.w3.org/2000/P3Pv1"
    xmlns:web="http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
  <web:RDF>

    <POLICY-REF web:about="/P3P/Policy1.p3p">
      <PREFIX>/docs/</PREFIX>
      <METHOD>GET</METHOD>
      <METHOD>HEAD</METHOD>
    </POLICY-REF>

    <POLICY-REF web:about="/P3P/Policy2.p3p">
      <PREFIX>/docs/</PREFIX>
      <METHOD>PUT</METHOD>
      <METHOD>DELETE</METHOD>
    </POLICY-REF>

  </web:RDF>
</POLICY-REFERENCES>

[10]	method-element	=	`<METHOD>` Methods `</METHOD>`
Here, `Method` is defined in the section 5.1.1 of [HTTP1.1].

2.3.3 Direct and Indirect References

Policy reference files may refer directly or indirectly to policies. A direct reference to a policy is a policy URI which, when fetched, returns the XML document which makes up that policy. An indirect reference to a policy is a policy URI which, when fetched, returns a new policy URI. The new policy URI returned by an indirect reference MAY, itself, be an indirect reference, though this is discouraged for performance reasons.

Direct and indirect references are recognized by the HTTP return code given by the server when fetched. When the URI of a direct policy reference is fetched, the server SHOULD return a 200-class HTTP return code or a 301 (Moved Permanently) HTTP return code (or an error code, if appropriate). It MUST NOT give a 302 (Found), return code as a response. When the URI of an indirect policy reference is fetched, a 302 return code MUST be given, unless an error (400- or 500-class) return code is appropriate. When a 302 return code is returned, it MUST include a Location response header giving the actual policy URI.

Services MAY choose to use direct or indirect policy references as appropriate (so long as the requirements under Immutability of Policies are respected). A direct policy reference will result in the best performance for user agents that are processing those policies. Due to the immutability rule, if a user agent receives a direct policy reference to a URI that it has already fetched, then no additional network activity is required in order to process that policy. This results in quicker response time for the user agent.

2.3.3.1 Purpose of Indirect Policy References

Indirect policy references require at least one additional network round trip to locate the actual policy. This results in reduced performance for the user agent. However, it allows for more flexible policy deployment for certain organizations. An example will assist in illustrating:

Imagine that an imaginary company, CatalogExample, is establishing a worldwide Web presence. Its default Web site, www.catalog.example.com, provides links to a number of country-specific sites. For purposes of this example, assume that CatalogExample starts by deploying four localized sites: usa.catalog.example.com (USA), www.catalog.example.co.uk (United Kingdom), www.catalog.example.com.ru (Russia), and www.catalog.example.com.jp (Japan). Let us assume that each of these sites has their content developed locally. This allows the sites to be better tailored to their local audiences.

However, the CatalogExample company has decided that it will have a single privacy policy that will apply to all of their sites around the world. They could do this by deploying that privacy policy on their master Web site (www.catalog.example.com), and having pages on their localized servers reference that policy. When CatalogExample company wishes to update their privacy policy, then by the Immutability of Policies rule, they must place that policy at a new URI. Then the policy references on all of their sites must be changed. This will probably involve work by several Webmasters and Webmistresses in various parts of the globe. The problem becomes far worse when CatalogExample expands to more of the world, and has perhaps 20 or 50 localized Web sites.

Indirect policy references are intended as a solution to this management problem. Each of the local CatalogExample sites can contain a policy URI pointing to the main CatalogExample server. Fetching this URI returns a reference to the currently-applicable privacy policy. For example, imagine that the CatalogExample company wants to gather customers' e-mail addresses to send them a note listing weekly specials. Each of the local servers could use an indirect policy URI of http://www.catalog.example.com/privacy/P3P/policy-weeklyspecial. Resolving this URI would then return a link to the actual privacy policy; perhaps this might be http://www.catalog.example.com/privacy/P3P/policy-weeklyspecial-3.xml. Now, when the corporation wishes to update the privacy policy that applies to the weekly special registration form, they need only update in a single location, regardless of how many servers reference that policy.

In general, services should use direct policy references whenever it is feasible. Indirect policy references are expected to be used only by organizations with large and diverse Web presences.

Note that services SHOULD make indirect policy references only across URIs that are under the same organizational control, to help insure the accuracy of the policy statement. However, there is no technical means to enforce this requirement. Indirect policy references MAY be to URIs on other hosts or even in other domains, depending on the structure of an organization's Web presence.

2.3.3.2 Handling Indirect References

When a user agent receives a policy reference, there is no way for it to tell if it is a direct or indirect policy reference. To process the policy properly, the user agent MUST fetch the URI specified in the policy reference. If that reference returns a 302 (Found) return code, then the user agent MUST fetch the URI given in the Location header to locate the actual policy in order to process the policy. Note that once a policy is fetched by direct reference, it need not be fetchd again (as long as the user agent records the relevant information). However an indirect reference requires rechecking to make sure it has not changed (unless an Expires or Cache-Control HTTP header indicates that it has not changed).

2.3.4 Embedded Content

HTML pages often contain links to other resources that are directly embedded in the page, such as images, sounds, layers or frames. Thus, in order to render the page, the user agents needs to make additional requests which might or might not be covered by the policy in effect for the page that is currently laid out.

As described in section 2.1.1 Mechanisms, the preferred method for such situations is to declare all policies in effect in a single policy reference file. If the policy reference file does not contain a POLICY-REF covering a given URI that links to embedded content (e.g., the src-attribute of an IMG-tag) it SHOULD initially assume that NO policy is in effect for the given resource. However, user agents MAY wish to issue a HEAD request to such a URI before actually requesting the resource, in order to find the policy in effect.

2.4 Use of Policy References

2.4.1 Non-ambiguity

A very important rule of policy references is that of non-ambiguity: For each resource at a Website there MUST be at most one policy active at any given time. Thus two policy reference files on a given site MUST NOT declare two or more different policy URIs for the same resource.

While the need to check for such ambiguities within a single policy reference file is obvious, user agents MAY also track policy declarations across an entire website, in order to detect ambiguities in policy declarations.

See also the section on Immutability of Policies for a discussion of non-ambiguity over time (immutability).

2.4.2 Multiple Languages

Multiple language versions (translations) of the same policy can be offered by the server using the HTTP "Content-Language" header to properly indicate that a particular language has been used for the policy. This is useful so that human-readable fields such as entity and consequence can be presented in multiple languages. The same mechanism can also be used to offer multiple language versions for data schemas. Whenever Content-Language is used to distinguish policies at the same URI that are offered in multiple languages, the policies MUST have the same meaning in each language.

2.4.3 Immutability of Policies

An essential requirement on policies is the so-called immutability of policies: with one exception, policies that are directly referenced at a certain URI cannot be changed. This way, the URI of a policy acts like a unique identifier for the policy, and any new policy must therefore use a new different URI. The only exception to this general principle is when multiple language versions (translations) of the same policy are offered by the server using the HTTP "Content-Language" tag.

P3P clients MAY check for immutability of policies, by comparing a cached version of a policy (and its Content-Language if present) with the corresponding freshly retrieved policy (and Content-Language if present). If a user agent discovers that the two policies are different but retain the same URI, then it MUST treat the resource covered by the changed policy as if it has no P3P policy, UNLESS they have two different values of Content-Language.

Note that immutability of policies only holds to policies that are directly referenced: the URI returned when an indirect policy reference is fetched MAY change over time; after all, this is the purpose behind indirect policy references. Indirect policy references MUST NOT be changed into direct policy references; if this is desired, a new policy-URI MUST be used.

2.5 Additional Requirements

2.5.1 The "Safe Zone"

Every P3P-enabled user agent and service SHOULD ensure that all the relevant communications that take place as part of fetching a P3P policy are part of a special "safe zone" in which minimal data collection takes place and any data that is collected is used only in non-identifiable ways.

To support this safe zone, P3P user agents SHOULD suppress the transmission of data unnecessary for the purpose of finding a site's policy until the policy has been fetched. Thus user agents SHOULD NOT send the HTTP Referer header, cookies, or user agent information while requesting a P3P policy.

In addition, P3P user agents MAY issue a HEAD request to a site in order to learn the location of the relevant policy before making other requests. This is a useful way to obtain a site's policy without making a request that could result in the transmission of data. However, since it might be possible for sites to detect the user's identify from the Accept-Language header (compare the [HTTP1.1] Specification, section 15.1.4 Privacy Issues Connected to Accept Headers), HEAD requests may be issued without an Accept-Language header in order to get the machine-readable part of the policy, and only if that is reasonably satisfactory, the policy in the appropriate language is fetched if necessary.

Servers SHOULD NOT require the receipt of an HTTP Referer header, cookies, user agent information, or other information unnecessary for responding to the request in order to serve a policy file. In addition, servers SHOULD NOT use in an identifiable way any information collected while serving a policy file or responding to a HEAD request.

Servers MAY return a PolicyRef header in the response headers when a P3P policy is requested. However, it is important to note that the PolicyRef header MUST be ignored, and that the "safe zone" requirements described in this section apply instead. Returning a PolicyRef header in such cases is permitted in consideration of the fact that administrators may find it easier to apply a P3P policy to all documents on a server, and that requiring policies to be served without a PolicyRef header may result in extra work for site administrators.

Note that the safezone requirements do not say that sites cannot keep identifiable information -- only that they SHOULD NOT use in an identifiable way any information collected while serving a policy file. Tracking down the source of a denial of service attack, for example, would be a legitimate reason to use this information and ignore the SHOULD.

2.5.2 Non-Discrimination of Policies

There are two important further requirements on the server side:

Reference a policy in response to any request:: P3P-compliant servers SHOULD include a link to a policy reference file for a web resource whenever possible.
Support HTTP HEAD requests: P3P-compliant servers SHOULD support HEAD requests for any documents that can be retrieved with GET requests. Whenever technically feasible, servers should give a valid response to a HEAD request for documents which are normally accessed by other HTTP methods as well (such as POST).

2.5.3 Security of Policy Transport

P3P policies and references to P3P policies SHOULD NOT, in themselves, contain any sensitive information. This means that there are no additional security requirements for transporting a reference to a P3P policy beyond the requirements of the document it is associated with; so, if an HTML document would normally be served over a non-encrypted session, then the P3P protocol would not require nor recommend that the document be served over an encrypted session when a reference to a P3P policy is included with that document.

3. Policy Syntax and Semantics

Section 3.1 begins with an example of an English language privacy policy and a corresponding P3P policy in Section 3.1. P3P policies include general assertions that apply to the entire policy as well as specific assertions -- called statements -- that apply only to the handling of particular types of data referred to by data references. Section 3.2 describes the policy element and policy-level assertions. Section 3.3 describes statements and data references.

In the sections that follow a number of XML elements are introduced. Each element is given in <> brackets, followed by a list of valid attributes. All listed attributes are optional, except when tagged as mandatory. Note that many XML elements are shown in the BNF with separate beginning and ending tags, to allow optional elements inside them. If no elements are included, then, following standard XML rules, a self-closing element may be used instead.

3.1 Example policy

3.1.1 English language policy

The following is an example of an English-language privacy policy to be encoded as a P3P policy.

CatalogExample, of 50 Whitfield Road, Bethesda, MD 20814, USA, makes the following statement for the Web page at http://www.catalog.example.com/catalog/. We have a privacy seal from PrivacySeal.example.org. Our privacy policy is posted at http://www.catalog.example.com/PrivacyPractice.html. We do not provide access capabilities to information we may have about you.
We use cookies and collect your gender, information about your clothing preferences, and (optionally) your home address to customize our entry catalog pages and for our own research and product development. We retain this information indefinitely.
We also maintain server logs that include information about visits to the http://www.catalog.example.com/catalog/ page, and the types of browsers our visitors use. We use this information in order to maintain and improve our web site. We retain this information indefinitely.

The following is a more formal description, using the P3P element and attribute names:

Entity: CatalogExample, 50 Whitfield Road, Bethesda, MD 20814, USA
Disputes:
   resolution type: independent
   service: http://www.privacyseal.example.org
   description:PrivacySeal.example.org
Disclosure:
   Disclosure URI: http://www.catalog.example.com/PrivacyPractice.html
   Access to Identifiable Information: none

We may collect:
    dynamic.cookies (category = state)
    user.gender
    dynamic.miscdata (category = pref)
    user.home. (optional)
For purpose: Customization of the site to individuals, research and development
Retention: Indefinitely
Recipients: Only ourselves and our agents
Consequence: A site with clothes you would appreciate
We collect:
     dynamic.clickstream.server
     dynamic.http.useragent
For purpose: Web site and system administration, research and development
Retention: Indefinitely
Recipients: Only ourselves and our agents

3.1.2 XML encoding of policy

The following piece of [XML] captures the information as expressed above. P3P policies are statements that are properly expressed as well-formed XML. The policy syntax will be explained in more detail in the sections that follow.

Example 3.1

<POLICY xmlns="http://www.w3.org/2000/P3Pv1"
        discuri="http://www.catalog.example.com/PrivacyPractice.html">
 <ENTITY>
 <DATA-GROUP>
  <DATA ref="#business.name">CatalogExample</DATA>
  <DATA ref="#business.contact-info.postal.street.line1">50 Whitfield Road</DATA>
  <DATA ref="#business.contact-info.postal.city">Bethesda</DATA>
  <DATA ref="#business.contact-info.postal.stateprov">MD</DATA>
  <DATA ref="#business.contact-info.postal.postalcode">20814</DATA>
  <DATA ref="#business.contact-info.postal.countrycode">US</DATA>
 </DATA-GROUP>
 </ENTITY>
  <DISPUTES-GROUP>
     <DISPUTES resolution-type="independent" 
               service="http://www.PrivacySeal.example.org"
               short-description="PrivacySeal.example.org">
       <IMG src="http://www.PrivacySeal.example.org/Logo.gif"/>
     </DISPUTES>
  </DISPUTES-GROUP>
  <ACCESS><none/></ACCESS>
  <STATEMENT>
     <CONSEQUENCE>A site with clothes you would appreciate</CONSEQUENCE>
     <RECIPIENT><ours/></RECIPIENT>
     <PURPOSE><custom/><develop/></PURPOSE>
     <RETENTION><indefinitely/></RETENTION>
     <DATA-GROUP>
       <DATA ref="#dynamic.cookies"><CATEGORIES><state/></CATEGORIES></DATA>
       <DATA ref="#dynamic.miscdata"><CATEGORIES><preference/></CATEGORIES></DATA>
       <DATA ref="#user.gender"/>
       <DATA ref="#user.home." optional="yes"/>
     </DATA-GROUP>
  </STATEMENT>
  <STATEMENT>
    <RECIPIENT><ours/></RECIPIENT>
    <PURPOSE><admin/><develop/></PURPOSE>
    <RETENTION><indefinitely/></RETENTION>
    <DATA-GROUP>
      <DATA ref="#dynamic.clickstream.server"/>
      <DATA ref="#dynamic.http.useragent"/>
    </DATA-GROUP>
  </STATEMENT>
</POLICY>

3.2 Policies

This section defines the syntax and semantics of P3P policies. All policies MUST be encoded using [UTF-8]. P3P servers MUST encode their policies using this syntax. P3P user agents MUST be able to parse this syntax.

3.2.1 The `POLICY` element

The POLICY element contains a complete P3P policy. Each P3P policy MUST contain exactly one POLICY element. The policy element MUST contain an ENTITY element that identifies the legal entity making the representation of the privacy practices contained in the policy. In addition, the policy element MUST contain an ACCESS element, at least one STATEMENT element, and optionally a DISPUTES-GROUP element and one or more extensions.

<POLICY>: includes one or more statements. Each statement includes a set of disclosures as applied to a set of data elements.
discuri (mandatory attribute): URI of the natural language privacy statement of the policy, which should include information on how to contact the service with questions or concerns.

[11]
policy

=

`<POLICY xmlns="http://www.w3.org/2000/P3Pv1" discuri=` quoted-URI `>` *extension entity access [disputes-group] 1*statement-block *extension `</POLICY>`

[12]
quoted-URI

=

`"` URI `"`

Here, URI is defined as per RFC 2396 [URI].

3.2.2 The ENTITY element

The ENTITY element gives a precise description of the legal entity making the representation of the privacy practices.

<ENTITY>: identifies the legal entity making the representation of the privacy practices contained in the policy

The ENTITY element contains a description of the legal entity consisting of DATA elements referencing (all or part of) the fields of the business dataset: it MUST contain both the legal entity's name as well as contact information such as postal address, telephone number, email address, or other information that individuals may use to contact the entity about their privacy policy. Note that some laws and codes of conduct require entities to include a postal address or other specific information in their contact information.

[13]
entity

=

"<ENTITY>" *extension entitydescription *extension "</ENTITY>"

[14]
entitydescription

=

<DATA-GROUP> `<DATA ref="#business.name"/>` PCDATA </DATA> *(`<DATA ref="#business." string `/>` PCDATA </DATA>) </DATA-GROUP>

Here, string is defined as a [UTF-8] string (with " and & escaped) among the values that are allowed by the business dataset. PCDATA is defined as in [XML].

3.2.3 The `ACCESS` element

The ACCESS element indicates whether the site provides access to various kinds of information.

<ACCESS>: the ability of the individual to view identifiable information and address questions or concerns to the service provider. Service providers MUST disclose one value for the access attribute. The method of access is not specified. Any disclosure is not meant to imply that access to all data is possible, but that some of the data may be accessible and that the user should communicate further with the service provider to determine what capabilities they have.
Note that service providers may also wish to provide capabilities to access information collected through means other than the Web at the discuri. However, the scope of P3P statements are limited to data collected through HTTP or other Web transport protocols. Also, if access is provided through the Web, use of strong authentication and security mechanisms for such access is recommended; however, security issues are outside the scope of this document.

The ACCESS element must contain one among the following elements:

<nonindent/>: Identifiable Data is Not Used
<contact/>: Identifiable Contact Information: access is given to identifiable online and physical contact information (e.g., users can access things such as a postal address).
<other_ident/>: Other Identifiable Information: access is given to certain other information linked to an identifiable person (e.g., users can access things such as their online account charges).
<contact_and_other/>: Identifiable Contact Information and Other Identifiable Information: access is given to identifiable online and physical contact information as well as to other information linked to an identifiable person.
<all/>: All Identifiable Information: access is given to all identifiable information.
<none/>: None: no access to identifiable information is given.

[15]
access

=

"<ACCESS>" access_disclosure *extension </ACCESS>

[16]
access-disclosure

=

"<nonident/>" | ; Identifiable Data is Not Used "<contact/>" | ; Identifiable Contact Information "<other_ident/>" | ; Other Identifiable Information
"<contact_and_other/>" | ; Identifiable and Other Contact Information "<all/>" | ; All Identifiable Information "<none/>" ; None

3.2.4 The `DISPUTES` element

A policy SHOULD contain a DISPUTES-GROUP element, which contains one or more DISPUTES elements. These elements describe dispute resolution procedures that may be followed for disputes about a services' privacy practices. Each DISPUTES element can optionally contain a LONG-DESCRIPTION and IMG tag, containing respectively a long human-readable description and an image logo, and a a REMEDIES element that specifies the possible remedies in case a policy breach occurs.

<DISPUTES>

Describes dispute resolution procedures that may be followed for disputes about a services' privacy practices, or in case of protocol violation.

resolution-type (mandatory attribute)

takes one of the following four values:

Customer service [service]: Individual may complain to the web site's customer service representative for resolution of disputes regarding the use of collected data. The description MUST include information about how to contact customer service.
Independent organization [independent]: Individual may complain to an independent organization for resolution of disputes regarding the use of collected data. The description MUST include information about how to contact the third party organization.
Court [court]: Individual may file a legal complaint against the web site.
Applicable law [law]: Disputes arising in connection with the privacy statement will be resolved in accordance with the law referenced in the description.

service (mandatory attribute)

URI of the customer service web page or independent organization, or URI for information about the relevant court or applicable law

verification

URI or certificate that can be used for verification purposes. It is anticipated that seal providers will provide a mechanism for verifying a site's claim that they have a seal.

short-description

A short human readable description of the name of the appropriate legal forum, applicable law, or third party organization; or contact information for customer service if not already provided at the service URI. No more than 255 [UTF-8] characters.

The DISPUTES element can contain a LONG-DESCRIPTION element, where a human readable description is present: this should contain the name of the appropriate legal forum, applicable law, or third party organization; or contact information for customer service if not already provided at the service URI.

<LONG-DESCRIPTION>: This element contains a (possibly long) human readable description.

<IMG>: An image logo (for example, of the independent organization or relevant court)
src (mandatory attribute): URI of the image logo
width: width in pixels of the image logo
height: height in pixels of the image logo
alt: very short textual alternative for the image logo

[17]
disputes-group

=

"<DISPUTES-GROUP>" *extension 1*dispute *extension "</DISPUTES-GROUP>"

[18]
dispute

=

"<DISPUTES" " resolution-type=" '"'("service"|"independent"|"court"|"law")'"' " service=" quoted-URI [" verification=" quoted-string] [" short-description=" quoted-string] "/>" [longdescription] [image] [remedies] *extension "</DISPUTES>"

[19]
longdescription

=

<LONG-DESCRIPTION> PCDATA </LONG-DESCRIPTION>

[20]
image

=

"<IMG src=" quoted-URI [" width=" `"` number `"`] [" height=" `"` number `"`] [" alt=" quoted-string] "/>"

[21]
quoted-string

=

`"` string `"`

Here, string is defined as a [UTF-8] string (with " and & escaped), and PCDATA is defined as in [XML].

Note that there can be multiple assurance services, specified via multiple occurrences of DISPUTES within the DISPUTES-GROUP element. These fields are expected to be used in a number of ways, from representing that one's privacy practices are self assured, audited by a third party, or under the jurisdiction of a regulatory authority.

3.2.5 The `REMEDIES` element

Each DISPUTES element SHOULD contain a REMEDIES element that specifies the possible remedies in case a policy breach occurs.

<REMEDIES>: Remedies in case a policy breach occurs.

The REMEDIES element must contain one or more among the following:

<correct/>: Errors or wrongful actions arising in connection with the privacy policy will be remedied by the service.
<money/>: If the service provider violates its privacy policy it will pay the individual an amount specified in the human readable privacy policy or the amount of damages.
<law/>: Remedies for breaches of the policy statement will be determined based on the law referenced in the human readable discription.

[22]	remedies	=	"<REMEDIES>" 1remedy extension "</REMEDIES>"
[23]	remedy	=	"<correct/>" \| "<money/>" \| "<law/>"

3.3 Statements

Statements describe data practices that are applied to particular types of data.

3.3.1 The `STATEMENT` element

The STATEMENT element is a container that groups together a PURPOSE element, a RECIPIENT element, a DATA-GROUP element, and optionally a CONSEQUENCE element and one or more extensions. All of the data referenced by the DATA-GROUP is handled according to the disclosures made in the other elements contained by the statement. Thus, sites may group elements that are handled the same way and create a statement for each group. Sites that would prefer to disclose separate purposes and other information for each kind of data they collect can do so by creating a separate statement for each data element.

<STATEMENT>: data practices as applied to data elements.

[24]
statement-block

=

"<STATEMENT>" *extension [consequence] purpose recipient retention 1*data-group *extension "</STATEMENT>"

To simplify practice declaration, service providers may aggregate any of the disclosures (purposes, recipients, and identifiable use) within a statement over data elements. Service providers MUST make such aggregations as an additive operation. For instance, a site that distributes your age to ours (ourselves and our agents), but distributes your zip code to published (unrelated third parties), MAY say they distribute your name and zip code to ours and unrelated. Such a statement appears to distribute more data than actually happens. It is up to the service provider to determine if their disclosure deserves specificity or brevity.

Also, one must always disclose all options that apply. Consider a site with the sole purpose of collecting information for the purposes of contact (Contacting Visitors for Marketing of Services or Products). Even though this is considered to be for the current (Completion and Support of Current Activity) purpose, the site must state both contact and current purposes. Consider a site which distributes information to ours in order to redistribute it to public: the site must state both ours and public recipients.

3.3.2 The `CONSEQUENCE` element

STATEMENT elements may optionally contain a CONSEQUENCE element that can be shown to a human user to provide further explanation about a site's practices.

<CONSEQUENCE>: Consequences that can be shown to a human user to explain why the suggested practice may be valuable in a particular instance even if the user would not normally allow the practice.

[25]
consequence

=

"<CONSEQUENCE>" PCDATA "</CONSEQUENCE>"

3.3.3 The `PURPOSE` element

Each STATEMENT element MUST contain a PURPOSE element that contains one or more purposes of data collection or uses of data. Sites MUST classify their data practices into one or more of the six specified purposes.

<PURPOSE>: purposes for data processing relevant to the Web.

The PURPOSE element must contain one or more among the following:

<current/>: Completion and Support of Current Activity: Information may be used by the service provider to complete the activity for which it was provided, such as the provision of information, communications, or interactive services -- for example to return the results from a Web search, to forward email, or place an order.
<admin/>: Web Site and System Administration:Information may be used for the technical support of the Web site and its computer system. This would include processing computer account information, and information used in the course of securing and maintaining the site.
<develop/>: Research and Development: Information may be used to enhance, evaluate, or otherwise review the site, service, product, or market. This does not include personal information used to tailor or modify the content to the specific individual nor information used to evaluate, target, profile or contact the individual.
<contact/>: Contacting Visitors for Marketing of Services or Products: Information may be used to contact the individual for the promotion of a product or service. This includes notifying visitors about updates to the Web site.
<customization/>: Affirmative Customization: Information may be used to tailor or modify the content or design of the site only to specifications affirmatively selected by the particular individual during a single visit or multiple visits to the site. For example, a financial site that lets users select several stocks whose current prices are displayed whenever the user visits.
<targeting/>: One-time Targeting: Information may be used to tailor or modify content or design of the site not affirmatively selected by the particular individual where the information is used only for a single visit to the site and not used for any kind of future customization. For example, an online store that suggests other items a visitor may wish to purchase based on the items he has already placed in his shopping basket.
<profiling/>: Individual Profiling: Information may be used to create or build a record on the particular individual or computer for the purpose of compiling habits or personally identifiable information of that individual or computer. For example, an online store that suggests items a visitor may wish to purchase based on items he has purchased during previous visits to the web site.
<other-purpose> string </other-purpose>: Other Uses: Information may be used in other ways not captured by the above definitions. (A human readable explanation should be provided in these instances).

Each type of purpose can have the following optional attribute:

change_preferences: Whether or not the site allows individuals to change their preferences with regard to a particular purpose. The default is "no". If the "yes" value is used it indicates that the site offers some mechanism for individuals to request that their data not be used for that purpose. There MUST be information about how to take advantage of this mechanism at the discuri.

[26]
yesno

=

"yes" | "no"

[27]
purpose

=

"<PURPOSE>" 1*purposevalue *extension "</PURPOSE>"

[28]
purposevalue

=

"<current" [change] "/>" | ; Completion and Support of Current Activity "<admin" [change] "/>" | ; Web Site and System Administration "<develop" [change] "/>" | ; Research and Development "<contact" [change] "/>" | ; Contacting Visitors for Marketing of Services or Products "<customization" [change] "/>" | ; Affirmative Customization "<targeting" [change] "/>" | ; One-time Targeting "<profiling" [change] "/>" | ; Individual Profiling "<other-purpose" [change] " >" PCDATA "</other-purpose>"; Other Uses

[29]
change

=

" change_preferences=" `"` yesno `"`

Service providers MUST use the above elements to explain the purpose of data collection. Service providers MUST disclose all that apply. If a service provider does not disclose that a data element will be used for a given purpose, that is a representation that data will not be used for that purpose. Service providers that disclose that they use data for "other" purposes MUST provide human readable explanations of those purposes.

Note, that the working group discussed at legnth the possibility of allowing sites to distinguish between purposes they may engage in and purposes they will engage in. The consensus of the working group was that such a distinction is not necessary. However, some members disagreed with this conclusion stating:

Yes, no and may all need to be response options in the vocabulary. If no and may are the only options, then the meaning of may is corrupted to equal yes. May should be an option that reflects its true meaning -- yes or no. If may by default means yes, because yes is not provided as a response option, the consumer will be misled. May should be used to imply that there are a set of rules underlying the term that consumers can refer to understand a privacy policy. If may means yes, the consumer is less likely to investigate via a click-through to the Web site's privacy policy. Potentially, this seemingly simple solution -- no and may -- will be a significant barrier to commerce as consumers are confused by the meaning of the truncated choices of only no and may. Those who argue that providing all three choices -- yes, may, no -- is an attempt by Web sites to mislead consumers are missing the point. In the arena of privacy protection, accuracy in stating a privacy policy is critical to building trust and confidence in the consumer about how information is used. In the interest of software simplicity, limiting consumer preference choices to no and may will do a disservice to the consumer -- and to the Web sites that are trying to communicate accurately with consumers about their policies.

3.3.4 The `RECIPIENT` element

Each STATEMENT element MUST contain a RECIPIENT element that contains one or more recipients of the collected data. Sites MUST classify their recipients into one or more of the six recipients specified.

<RECIPIENT>: the legal entity, or domain, beyond the service provider and its agents where data may be distributed.

The RECIPIENT element must contain one or more among the following:

<ours/>: Ourselves and/or our agents: Ourselves and our agents. An agent in this instance is defined as a third party that processes data only on behalf of the service provider for the completion of the stated purposes. (e.g., The service provider and its printing bureau which prints address labels and does nothing further with the information.)
<same/>: Legal entities following our practices: Legal entities who use the data on their own behalf under equable practices. (e.g., consider a service provider that grants the user access to collected personal information, and also provides it to a partner who uses it once but discards it. Since the recipient, who has otherwise similar practices, cannot grant the user access to information that it discarded, they are considered to have equable practices.)
<other-recipient/>: Legal entities following different practices: Legal entities that are constrained by and accountable to the original service provider, but may use the data in a way not specified in the service provider's practices (e.g. The service provider collects data that is shared with a partner who may use it for other purposes. However, it is in the service provider's interest to ensure that the data is not used in a way that would be considered abusive to the users' and its own interests.)
<delivery/>: Delivery services possibly following different practices: Legal entities performing delivery services that may use data for purposes other than completion of the stated purpose. This should also be used for delivery services whose data practices are unknown.
<public/>: Public fora: Public fora such as bulletin boards, public directories, or commercial CD-ROM directories.
<unrelated/>: Unrelated third parties: Legal entities whose data usage practices are not known by the original service provider.

[30]
recipient

=

"<RECIPIENT>" 1*recipientvalue *extension "</RECIPIENT>"

[31]
recipientvalue

=

"<ours/>" | ; only ourselves and our agents "<same/>" | ; legal entities following our practices "<other-recipient/>" | ; legal entities following different practices "<delivery/>" | ; delivery services following different practices "<public/>" | ; public fora "<unrelated/>" ; unrelated third parties

Service providers MUST disclose all the recipients that apply. Note that in some cases the above set of recipients may not completely describe all the recipients of data. For example, the issue of transaction facilitators, such as shipping or payment processors, who are necessary for the completion and support of the activity but may follow different practices was problematic. Currently, only delivery services can be explicitly represented in a policy. Other such transaction facilitators should be represented in whichever category most accurately reflects their practices with respect to the original service provider. The working group decided to include a special element for delivery services, but not for payment processors (such as banks or credit card companies) for the following reasons: Financial institutions will typically have separate agreements with their customers regarding the use of their financial data, while delivery recipients typically do not have an opportunity to review a delivery service's privacy policy.

Note that the <delivery/> element SHOULD NOT be used for delivery services that agree to use data only on behalf of the service provider for completion of the delivery.

3.3.5 The `RETENTION` element

Each STATEMENT element MUST contain a RETENTION element that indicates the kind of retention policy that applies to the data referenced in that statement.

<RETENTION>: the type of retention policy in effect

The RETENTION element must contain one of the following:

<no-retention/>: Information is not retained for more than a brief period of time necessary to make use of it during the course of a single online interaction. Information MUST be destroyed following this interaction and MUST not be logged, archived, or otherwise stored. This type of retention policy would apply, for example, to services that keep no Web server logs, set cookies only for use during a single session, or collect information to perform a search but do not keep logs of searches performed.
<stated-purpose/>: For the stated purpose: Information is retained to meet the stated purpose. This requires information to be discarded at the earliest time possible. Sites MUST have a retention policy that establishes a destruction time table. The retention policy MUST be included in or linked from the site's human-readable privacy policy.
<legal-requirement/>: As required by law or liability under applicable law: Information is retained to meet a stated purpose, but the retention period is longer because of a legal requirement or liability. For example, a law may allow consumers to dispute transactions for a certain time period therefore a business may for liability reasons decide to maintain records of transactions, or a law may affirmatively require a certain business to maintain records for auditing or other soundness purposes. Sites MUST have a retention policy that establishes a destruction time table. The retention policy MUST be included in or linked from the site's human-readable privacy policy.
<indefinitely/>: Indefinitely: Information is retained for an indeterminate period of time. The absence of a retention policy would be reflected under this option. Where the recipient is a public fora, this is the appropriate retention policy.
<business-practices/>: Determined by service provider's business practice: Information is rentained under a service provider's stated business practices. Sites MUST have a retention policy that establishes a destruction time table. The retention policy MUST be included in or linked from the site's human-readable privacy policy.

[32]
retention

=

"<RETENTION>" retentionvalue *extension "</RETENTION>"

[33]
retentionvalue

=

"<no-retention/>" | ; not retained "<stated-purpose/>" | ; for the stated purpose "<legal-requirement/>" | ; stated purpose by law "<indefinitely/>" | ; indeterminated period of time "<business-practices/>" ; by business practices

3.3.6 The `DATA-GROUP` and `DATA` elements

Each STATEMENT element MUST contain at least one DATA-GROUP element that contains one or more DATA elements. DATA elements are used to describe the type of data that a site collects.

<DATA-GROUP>: describes the data to be transferred or inferred
base: base URI (cf. [URI]) for URI references present in ref attributes. The default value is the URI of the P3P base data schema (http://www.w3.org/TR/P3P/base).

<DATA>: describes the data to be transferred or inferred
ref (mandatory attribute): URI reference (cf. [URI]), where the fragment identifier part denotes the name of a data element/set, and the URI part denotes the corresponding dataschema. In case the URI part is not present, if the DATA element is contained within a DATA-GROUP element, then the default base URI is assumed to be the URI of the base attribute. In the other cases, as usual, the default base URI is a same-document reference ([URI]).
Data sets and elements are syntactically distinguished by the presence of a trailing dot after the set name. For example, the trailing dot indicates that user.home. is a data set. Remember that names of data elements and sets are case-sensitive (so, for example, user.home. is different from USER.HOME. or User.Home.).
optional: indicates whether or not the site requires visitors to submit this data element; "no" indicates that the data element is required, while "yes" indicates that the data element is not required. The default is "no". The optional attribute is used only in policies (not in dataschema definitions). Note that P3P does not include a mechanism for specifying that certain data practices are optional.

The following six attributes are only used when a new (not defined in the P3P [Base Data Schema]) data element or set is referenced:

name: denotes the name of a data element/set. Data sets and elements are syntactically distinguished by the presence of a trailing dot after the set name. For example, the trailing dot indicates that user.home. is a data set. Remember that names of data elements and sets are case-sensitive (so, for example, user.home. is different from USER.HOME. or User.Home.). Furthermore, in names of data elements/sets no number character can appear immediately following a dot.
typeref: URI reference (cf. [URI]), where the fragment identifier part denotes the type of a data element/set, and the URI part denotes the corresponding dataschema where it is defined. As usual, the default base URI is a same-document reference ([URI]).
template: specifies whether or not the corresponding data element is part of a type definition only. If set to "yes", the data element is a type definition, and is not actually representing a data element with an associated value. The default value is "no".
short-description: a string denoting the short display name of the data element/set, no more than 255 [UTF-8] characters.
size: denotes the maximum number of [UTF-8] characters that are needed to store the data element. This information can be useful for example for clients that want to efficiently build data repositories. The default value of 0 indicates that the data element can be arbitrarily large.

DATA elements can contain the actual data (like we have already seen in the case of the ENTITY element), and can contain related category information. When used in a dataschema, they can also contain a long description of the data element/set, using the LONG-DESCRIPTION element.

[34]
data-group

=

"<DATA-GROUP"
[" base=" quoted-URI]
>" 1*data-reference *extension "</DATA-GROUP>"

[35]
data-reference

=

"<DATA" ( " ref=`" URI-reference "`" [" optional=" yesno] ">" [categories] ; the categories of the data element. [PCDATA] ; the eventual value of the data element ) | ( " name=" quoted-string [" typeref=`" URI-reference "`"] [" template=" yesno] [" short-description=" quoted-string] [" size=" `"` number `"`] ) ; default is 0 (unlimited size) ">" [categories] ; the categories of the data element. [longdescription] ; the eventual long description of the data element ) "</DATA>"

Here, URI-reference is defined as in [URI].

For example, to reference the user's home address city, all the elements of the data set user.business. and (optionally) all the elements of the data set user.home.phone., the service would send the following references inside a P3P policy:

<DATA-GROUP>
<DATA ref="#user.home.city"/>
<DATA ref="#user.home.phone." optional="yes"/>
<DATA ref="#user.business."/>
</DATA-GROUP>

When the actual value of the data is known, it can be expressed inside the DATA element, like eventual extensions. For example, as seen in the example policy:

<ENTITY>
  <DATA ref="#business.name">CatalogExample</DATA>
  <DATA ref="#business.contact-info.postal.street.line1">50 Whitfield Road</DATA>
  <DATA ref="#business.contact-info.postal.city">Bethesda</DATA>
  <DATA ref="#business.contact-info.postal.stateprov">MD</DATA>
  <DATA ref="#business.contact-info.postal.postalcode">20814</DATA>
  <DATA ref="#business.contact-info.postal.countrycode">US</DATA>
</ENTITY>

3.4 Categories

Categories are elements inside data elements that provide hints to users and user agents as to the intended uses of the data. Categories are vital to making P3P user agents easier to implement and use; they allow users to express more generalized preferences and rules over the exchange of their data. Categories are often included when defining a new element or when referring to data that the user is prompted to type in (as opposed to data stored in the user data repository).

In the current version of P3P, the following elements are used to denote data categories:

[36]
categories

=

"<CATEGORIES>" 1*category "</CATEGORIES>"

[37]
category

=

"<physical/>" | ; Physical Contact Information "<online/>" | ; Online Contact Information "<uniqueid/>" | ; Unique Identifiers "<purchase/>" | ; Purchase Information "<financial/>" | ; Financial Information "<computer/>" | ; Computer Information "<navigation/>" | ; Navigation and Click-stream Data "<interactive/>" | ; Interactive Data "<demographic/>" | ; Demographic and Socioeconomic Data "<content/>" | ; Content "<state/>" | ; State Management Mechanisms "<political/>" | ; Political Information "<health/>" | ; Health Information "<preference/>" | ; Preference Data "<other/>" ; Other

<physical/>: Physical Contact Information: Information that allows an individual to be contacted or located in the physical world -- such as phone number or address.
<online/>: Online Contact Information: Information that allows an individual to be contacted or located on the Internet -- such as email. Often, this information is independent of the specific computer used to access the network. (See the category "Computer Information")
<uniqueid/>: Unique Identifiers: Non-financial identifiers issued for purposes of consistently identifying the individual -- such as SSN or Web site IDs.
<purchase/>: Purchase Information: Information actively generated by the purchase of a product or service, including information about the method of payment.
<financial/>: Financial Information: Information about an individual's finances including account status and activity information such as account balance, payment or overdraft history, and information about an individual's purchase or use of financial instruments including credit or debit card information. Information about a discrete purchase by an individual, as described in "Purchase Information," alone does not come under the definition of "Financial Information."
<computer/>: Computer Information: Information about the computer system that the individual is using to access the network -- such as the IP number, domain name, browser type or operating system.
<navigation/>: Navigation and Click-stream Data: Data passively generated by browsing the Web site -- such as which pages are visited, and how long users stay on each page.
<interactive/>: Interactive Data: Data actively generated from or reflecting explicit interactions with a service provider through its site -- such as queries to a search engine, logs of account activity, or purchases made on the Web.
<demographic/>: Demographic and Socio-economic Data: Data about an individual's characteristics -- such as gender, age, and income.
<content/>: Content : The words and expressions contained in the body of a communication -- such as the text of email, bulletin board postings, or chat room communications.
<state/>: State Management Mechanisms: Mechanisms for maintaining a stateful session with a user or automatically identifying users who have visited a particular site or accessed particular content previously -- such as HTTP cookies.
<political/>: Political Information: Membership in or affiliation with groups such as religious organisations, trade unions, professional associations, political parties, etc.
<health/>: Health Information: Health Information: information about an individual's physical or mental health, sexual orientation, use or inquiry into health care services or products, and purchase of health care services or products.
<preference/>: Preference Data: Data about an individual's likes and dislikes -- such as favorite color or musical tastes.
<other/>: Other: Other types of data not captured by the above definitions. (A human readable explanation should be provided in these instances.)

The Computer, Navigation, Interactive and Content categories can be distinguished as follows. The Computer category includes information about the user's computer including IP address and software configuration. Navigation data describes actual user behavior related to browsing. When an IP address is stored in a log file with information related to browsing activity, both the Computer category and the Navigation category should be used. Interactive Data is data actively solicited to provide some useful service at a site beyond browsing. Content is information exchanged on a site for the purposes of communication.

The Other category should be used only when data is requested that does not fit into any other category.

P3P uses categories to give users and user agents additional hints as to what type of information is requested from a service. While most data in the Base Data Schema is in a known category (or a set of known categories), some data elements can be in a number of different categories, depending on the situation. The former are called fixed-category data elements (or "fixed data elements" for short), the latter variable-category data elements ("variable data elements"). Both types of elements are briefly described in the two sections below.

3.4.1 Fixed-Category Data Elements

Most of the elements in the base data schema are so called "fixed" data elements: they belong to one or at most two category classes. By assigning a category invariably to elements in the base data schema, services and users are able to refer to entire groups of elements simply by referencing the corresponding category. For example, using [APPEL], the privacy preferences exchange language, users can write rules that prevent their user agent from giving out any data element in a certain category.

When creating data schemas for fixed data elements, schema creators have to explicitly enumerate the categories that these element belong to. For example:

<DATA name="postal.street.line1" typeref="#text"
short-description="Street Address, Line 1" template="yes">
<CATEGORIES><physical/></CATEGORIES>
</DATA>

If an element belongs to multiple categories, multiple elements referencing the appropriate categories can be used. For example, the following piece of XML can be used to declare that the data elements in user.name. have both category "physical" and "demographic":

<DATA name="user.name." typeref="#personname."
short-description="User's Name" template="yes">
<CATEGORIES><physical/><demographic/></CATEGORIES>
</DATA>

Please note that the category classes of fixed data elements can not be overridden, for example by writing rules or policies that assign a different category to a known fixed base data element. User Agents MUST ignore such categories and instead use the original category (or set of categories) listed in the schema definition. User Agents MAY preferably alert the user that a fixed data element is used together with a non-standard category class.

3.4.2 Variable-Category Data Elements

Not all data elements in the base data schema belong to a pre-determined category class. Some elements can contain information from a range of categories, depending on a particular situation. Such elements are called variable-category data elements (or "variable data element" for short). Although most variable data elements in the P3P Base Data Schema are combined in the dynamic. element set, they can appear in any data set, even mixed with fixed-category data elements.

When creating a schema definition for such elements, schema authors MUST NOT list an explicit category attribute, otherwise the element becomes a fixed data element. For example when specifying the "Year" data type, which can take various categories depending on the situation (e.g. when used for a credit card expiration date vs. for a birth date), the following schema definition can be used:

<DATA name="date.ymd.year" typeref="#number" size="6"
short-description="Year" template="yes"/> 

This allows new schema extensions that reference such variable-category data types to assign a specific category to derived elements, depending on their usage in that extension. For example, an E-commerce schema extension could thus define a credit card expiration date as follows:

<DATA name="Card.ExpDate." typeref="#date.ymd."
short-description="Card Expiration Date" template="yes">
<CATEGORIES><financial/></CATEGORIES> </DATA>

Under these conditions, the variable data type date. is assigned a fixed category Financial Account Identifiers when being used for specifying a credit card expiration date.

Note that while user preferences can list such variable data elements without any additional category information (effectively expressing preferences over any usage of this element), services MUST always explicitly specify the categories that apply to the usage of a variable data element in their particular policy. This information has to appear as a category element in the corresponding DATA element listed in the policy, for example as in:

<POLICY ... >
...
<DATA ref="#dynamic.cookies"><CATEGORIES>

[1]	policy-reference-header	=	nsprefix `-PolicyRef: ` URI
Here, `URI` is defined as per RFC 2396 [URI]. `nsprefix` is the two-digit namespace declaration selected for the P3P headers in this message, according to [HTTP-EXT]. It may be any two-digit number that does not conflict with other namespace declarations in the response.

[2]	p3p-link-tag	=	`<link rel="P3Pv1" href="` URI `">``
Here, `URI` is defined as per RFC 2396 [URI].

[8]	prefix	=	`<PREFIX>` URI`</PREFIX>`
[9]	exclude	=	`<EXCLUDE>` URI `</EXCLUDE>`
Here, `URI` is defined as per RFC 2396 [URI].

[11]	policy	=	`<POLICY xmlns="http://www.w3.org/2000/P3Pv1" discuri=` quoted-URI `>` extension entity access [disputes-group] 1statement-block *extension `</POLICY>`
[12]	quoted-URI	=	`"` URI `"`
Here, URI is defined as per RFC 2396 [URI].

[17]	disputes-group	=	"<DISPUTES-GROUP>" extension 1dispute *extension "</DISPUTES-GROUP>"
[18]	dispute	=	"<DISPUTES" " resolution-type=" '"'("service"\|"independent"\|"court"\|"law")'"' " service=" quoted-URI [" verification=" quoted-string] [" short-description=" quoted-string] "/>" [longdescription] [image] [remedies] *extension "</DISPUTES>"
[19]	longdescription	=	<LONG-DESCRIPTION> PCDATA </LONG-DESCRIPTION>
[20]	image	=	"<IMG src=" quoted-URI [" width=" `"` number `"`] [" height=" `"` number `"`] [" alt=" quoted-string] "/>"
[21]	quoted-string	=	`"` string `"`
Here, string is defined as a [UTF-8] string (with " and & escaped), and `PCDATA` is defined as in [XML].

[26]	yesno	=	"yes" \| "no"
[27]	purpose	=	"<PURPOSE>" 1purposevalue extension "</PURPOSE>"
[28]	purposevalue	=	"<current" [change] "/>" \| ; Completion and Support of Current Activity "<admin" [change] "/>" \| ; Web Site and System Administration "<develop" [change] "/>" \| ; Research and Development "<contact" [change] "/>" \| ; Contacting Visitors for Marketing of Services or Products "<customization" [change] "/>" \| ; Affirmative Customization "<targeting" [change] "/>" \| ; One-time Targeting "<profiling" [change] "/>" \| ; Individual Profiling "<other-purpose" [change] " >" PCDATA "</other-purpose>"; Other Uses
[29]	change	=	" change_preferences=" `"` yesno `"`