Copyright © 2006 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
This is the specification of the Platform for Privacy Preferences 1.1 (P3P 1.1). This document, along with its normative references, includes all the specification necessary for the implementation of interoperable P3P 1.1 applications. P3P 1.1 is based on the P3P 1.0 Recommendation and adds some features using the P3P 1.0 Extension mechanism. It also contains a new binding mechanism that can be used to bind policies for XML Applications beyond HTTP transactions.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
Publication as a Working Group Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document is a Working Group Note describing the proposed P3P Version 1.1 (P3P11). The P3P Specification Working Group is lacking the necessary support from implementers to carry on through the Recommendation Process. Therefor the Working Group decided to publish the current P3P 1.1 Specification as a Working Group Note after a successful Last Call. In this Note, all Last Call comments are taken into account. The Working Group thinks that the Specification is usable and implementable. If there is sufficient support from implementers and the community at large, this work can be taken up and brought to Recommendation. The P3P community continues to discuss privacy issues and P3P implementation issues in the<EMAIL_ADDRESS>mailing list that is publicly archived. Comments should be directed to this list.
The P3P 1.1 Specification was developed from suggestions out of a Workshop in Dulles/Virginia and a Workshop in Kiel/Germany. The community at large gave feedback on limitations and shortcomings of P3P 1.0. As far as those suggestions have found sufficient support, they are now included in this P3P 1.1 Working Group Note. All new features are built using P3P's own Extension mechanism. Those extensions are contained in a new XML Schema in Appendix 5 and carry their own new namespace. All P3P 1.0 preserve their old namespace. Additionally, this Working Group Note contains all the errata to P3P 1.0.
This document has been produced by the P3P Specification Working Group as part of the Privacy Activity in the W3C Technology & Society Domain.
This document is governed by the 24 January 2002 CPP as amended by the W3C Patent Policy Transition Procedure. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
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.
The P3P1.1 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.
P3P version 1.0 is a protocol designed to inform Web users about 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:
The goal of P3P 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.
A number of changes were made in P3P version 1.1. These are enumerated in the change log at the end of this document. The most significant changes are summarized here:
OUR-HOST
element has been added for declaring domain
relationships, allowing user agents to recognize when hosts in
different domains are owned by the same entity or entities acting
as agents for one another.STATEMENT
elements and grouping
STATEMENT
elements together. This allows user agents
to better organize the summary display of P3P policies and obtain
opt-in or opt-out choices to a group of statements. DISPUTES
and REMEDIES
elements and their
sub-elements.RECIPIENT
element.demographic
element.ppurpose
element has been added added to allow user
agents to determine the primary reason why the data recipient is
collecting data.JURISDICTION
element has been added for declaring the
jurisdiction of data recipients.STATEMENT
element for use in compact policies. This
allows for the creation of compact policies that make more
granular statements about data practices than is possible with
the P3P 1.0 syntax.As an introduction to P3P, let us consider one common scenario that makes use of P3P. Claudia 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 Claudia is using a Web browser with P3P built in.
Claudia types the address for CatalogExample into her Web browser. Her browser is able to automatically fetch the P3P policy for 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 Claudia's Web browser checks this policy against the preferences Claudia has given it. Is this policy acceptable to her, or should she be notified? Let's assume that Claudia 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, Claudia 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 provides a separate P3P policy to cover this section of the site. Again, let's assume that this policy matches Claudia's preferences, so she gets no pop-up messages. Claudia 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: Claudia's name, address, credit card number, and telephone number. Another P3P policy is available that describes the data that is collected here and states that her data will be used only for completing the current transaction, her order.
Claudia's browser examines this P3P policy. Imagine that Claudia has told her browser that she wants to be warned whenever a site asks for her telephone number. In this case, the browser will pop up a message saying that this Web site is asking for her telephone number, and explaining the contents of the P3P statement. Claudia 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, Claudia 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.
P3P policies use XML with namespaces (cf. [XML] and [XML-Name]) encoding of the P3P vocabulary to provide contact information for 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. However, 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. In addition, note that each P3P policy is applied to specific Web resources (Web pages, images, cookies, etc.) listed in a policy reference file. By placing one or more P3P policies on a Web site, a company or organization does not make any statements about the privacy practices associated with other Web resources not mentioned in their policy reference file, with other online activities that do not involve data collected on Web sites covered by their P3P policy, or with offline activities that do not involve data collected on Web sites covered by their P3P policy.
In cases where the P3P vocabulary is not precise enough to describe a Web site's practices, sites should use the vocabulary terms that most closely match their practices and provide further explanations (as stated in Section 3.2). However, policies MUST NOT make false or misleading statements.
P3P 1.1 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 references to a P3P policy at a
well-known location, in P3P headers in HTTP responses, and in P3P
link
tags embedded in HTML content. These references 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.
The P3P 1.1 Specification gives implementers a lot of flexibility to determine the design and functionality of P3P user agents. However, the specification does include some requirements and guidelines for user agent implementers. Most of these can be found in section 6 and Appendix 7.
Web sites can implement P3P 1.1 on their servers by translating their
human-readable privacy policies into P3P syntax and then publishing the
resulting files along with a policy reference file that indicates the parts
of the site to which the policy applies. Automated tools can assist site
operators in performing this translation. P3P 1.1 can be implemented on
existing HTTP/1.1-compliant Web servers without requiring additional or
upgraded software. Servers may publish their policy reference files at a well-known location, or they may reference
their P3P policy reference files in HTML/XHTML content using a
link
tag. Alternatively, compatible servers may be configured to
insert a P3P extension header into all HTTP responses that indicates the
location of a site's P3P policy reference file.
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.
Significant sections were removed from earlier drafts of the P3P 1.0 specification in order to facilitate rapid implementation and deployment of a P3P first step. A future version of the P3P specification might incorporate those features after P3P 1.0 is deployed. Such 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 P3P 1.0 or 1.1:
The P3P 1.1 Specification contains the most urgent improvements suggested by the P3P Workshop of December 2002 in Dulles/Virginia. Some of the Work suggested by this Workshop and by the P3P Workshop in Kiel are delayed to later versions.
P3P 1.1 has been designed so that P3P 1.0 user agents can process P3P 1.1 policies and policy reference files. This implies both that the P3P 1.1 policies and policy reference files are fully compliant with the P3P 1.0 XML schema, and that the semantics of these files will not be misinterpreted by a user agent that interprets them according to the P3P 1.0 specification. All new syntax introduced in P3P 1.1 has been introduced as optional extensions using the P3P 1.0 extension mechanism. Changes to requirements or definitions introduced in P3P 1.1 add clarity where the P3P 1.0 specification is ambiguous, but do not cause a particular P3P vocabulary element to have different meanings in P3P 1.0 and P3P 1.1. In addition, some new requirements or features have been introduced in the P3P 1.1 specification that do not impact the ability of P3P 1.0 user agents to process P3P 1.1 policies and policy reference files. For the base data-schema, the guidelines described there apply.
Note, P3P 1.1 data schemas cannot be read by P3P 1.0 user agents. This only impacts P3P 1.0 user agents that download and parse data schemas, and only when they access P3P 1.1 web sites that make use of data schemas beyond the P3P base data schema.
The Platform for Privacy Preferences Version 1.1 (P3P 1.1) defines a format for machine-readable privacy notices. It aims at two classes of products: Collectors of personal information such as web-sites can generate P3P 1.1 output to define what personal data may be collected and how it may be used. User agents consume a P3P 1.1. They may display a human readable version of the privacy notice or change their behavior based on the content of the notice.
The P3P specification defines, with the exception of section 2.2.2, section 2.2.3 and section 4, an XML with namespaces syntax (cf. [XML] and [XML-Name]). In the following, for the sake of brevity we will liberally talk about "XML", meaning the more accurate "XML with namespaces".
As far as the non-XML syntax defined in this specification is concerned (section 2.2.2 defining P3P's HTTP header, section 2.2.3 defining usage of P3P in HTML, and section 4 defining compact policies), instead, the ABNF notation (together with the other constraints expressed in this specification using natural language) constitutes the normative definition.
The normative parts of this specification are identified by "Normative" & "Informative" labels within sections. The (non-normative) DTD provided formerly in Appendix 5 was removed due to the limits of expressiveness. The XML Schema is now the only normative source.
Individual conformance requirements or testable statements are identifiable in the P3P 1.1 specification as follows:
The following key words are used throughout the document and have to 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:
A BNF-like notation is also used thorough the specification: the [ABNF] notation used in this specification is specified in RFC2234 and summarized in Appendix 6. However, note that in the case of XML syntax, such ABNF syntax is only a grammar representative used to enhance readability (lacking, for example, all the syntactic flexibilities that are implicitly included in XML, e.g. whitespace rules, quoting using either single quote (') or double quote ("), character escaping, comments, case sensitivity, order of attributes, namespace handling), and as such it has no normative value. All the XML syntax defined in this specification MUST conform to the XML Schema for P3P (see Appendix 5), which, together with the other constraints expressed in this specification using natural language, constitutes the normative definition.
In privacy regulations, guidelines and papers about privacy a variety of terms are used to describe data that identifies an individual to varying degrees.
The European Union Directive 95/46/EC defines an identifiable person
as
one who can be identified, directly or indirectly, in particular by
reference to an identification number or to one or more factors specific to
his physical, physiological, mental, economic, cultural or social
identity.
The Directive also states that in determining whether a person
is identifiable account should be taken of all the means likely reasonably
to be used either by the controller or by any other person to identify the
said person; whereas the principles of protection shall not apply to data
rendered anonymous in such a way that the data subject is no longer
identifiable.
In Australia, personal information
is information about an
individual who can be identified, or whose identity could be reasonably
ascertained.
In Canada personal information
means information
about an identifiable
individual. In the United States, different
sectors have different standards for identifiability of data. Similarly, in
many other policy documents, terms such as personally identifiable
information (PII)
are often not defined or the cause for heated
debate.
The P3P Specification Working Group has taken the view point that most
information referring to an individual is identifiable
in some way. As
with other important areas of the specification, the goal of the working
group was to allow for a wide variety of understandings of identity in order
to allow data collectors to best express their policy and users to make
choices based on a definition of identity information that is important to
them. (More information on the debate and the definitions can be found in [Cranor,P3P].
IdentifiedData
The most common term in the specification is identified data
and
focuses on whether a service knows the data subject's identity.
Identified data
is information in a record or profile that can
reasonably be tied to an individual. Admittedly, this is a somewhat
subjective standard. For example, a data collector storing Internet Protocol
(IP) addresses (which can be created dynamically or could be static and
therefore tied to a particular computer used by a single individual) should
consider the IP address identified data
only when this data is added
to the record or profile of a specific individual. In the more common case,
where data collectors use IP addressing information in the aggregate or make
no attempt to tie the IP address to a specified individual or computer over a
long period of time, IP addresses are not considered identified even though
it is possible for someone (eg, law enforcement agents with proper subpoena
powers) to identify the individual based on the stored data.
As mentioned above, in the P3P context, any data that can be used
reasonably by a data controller or any other person to identify an individual
is considered to be identifiable data. The P3P specification uses the term
identified
to describe a subset of this data that can be reasonably be
used by a data collector without assistance from other parties to
identify an individual.
Non-IdentifiableData
The working group also felt that data collectors should be able acknowledge when they make specific attempts to anonymize information.
The term non-identifiable
data refers to efforts made specifically
to de-identify data. For example, a data collector collecting and storing IP
addresses but not using them should NOT call this data
non-identifiable
even in the common case where they have no plans to
identify an actual individual or computer. However, if a Web site collects IP
addresses, but actively deletes all but the last four digits of this
information in order to determine short term use, but insure that a
particular individual or computer cannot be consistently identified, then the
data collector can and should call this information non-identifiable.
Also, non-identifiable can be used in cases where no information is being
collected at all. Since most Web servers are designed to keep Web logs for
maintenance, this would most likely mean that the data collector has taken
specific efforts to ensure the anonymity of users.
Under the above definitions, a lot of information could be
identifiable
(not specifically made anonymous), but not
identified
(reasonably able to be tied to an individual or
computer).
The Working Group decided against an identified or identifiable label for particular types of data. However, user agent implementers have the option of assigning these or other labels themselves and building user interfaces that allow users to make decisions about web sites on the basis of how they collect and use certain types of data.
The Working Group felt that different user agent implementations could be created to focus on different concerns around data type. Therefore, the working group enabled the creation of a robust data schema including broad categories of information that may be considered sensitive by certain user groups. The Working Group hopes that a diverse set of user agents will be created to allow users the ability to make identity decisions based on specific collections and types of collects if they desire to do so. For example, a user agent could allow users to opt to be prompted when medical or financial identifier is being collected, independent of how that information is being used.
Cookies often store a unique number or database key that links to a database record, rather than storing the complete database record. Web sites that use P3P must disclose not only the types of data stored directly in a cookie, but also all data linked to a cookie. A large amount of data may be "linkable" to a cookie without actually being "linked" to that cookie.
A piece of data X is said to be linkable to a cookie Y if a key stored in cookie Y can be used to retrieve X either directly or indirectly. A direct retrieval might happen, for example, if the key is associated with a database record in which X is stored. An indirect retrieval might happen, for example, if the key is associated with a database record that contains a piece of data that may be used, in turn, as a key to retrieve a record in a second database, and X is stored in the second database. Furthermore, if cookie Y is stored in a server log file, the log file may facilitate further linking. For example, when cookie Y is replayed, it may be accompanied by a referrer field that includes additional identifiable information or even another key. Alternatively, imagine a web site that sets two cookies, Y and Z. Cookies Y and Z may get replayed in the same HTTP request and subsequently recorded side-by-side in the server log file. Thus all data associated with cookie Y are also linkable to cookie Z. Indeed, unless precautions are taken to minimize server log files and severely restrict the use of identifiable data, almost all data an entity stores about an individual are likely to be linkable to any cookies they have set on that individual's computer.
A piece of data X is said to be linked to a cookie Y if at least one of the following activities may take place as a result of cookie Y being replayed, immediately upon cookie replay or at some future time (perhaps as a result of retrospective analysis or processing of server logs):
Entities should consider their data collection and storage architectures carefully to determine what data may be linkable to their cookies and what data will actually be linked to each cookie. If data is linkable but not linked to a particular cookie, it does not have to be disclosed in a P3P statement concerning that cookie. However, should the entity associated with that P3P policy ever link the data for any reason other than to comply with law enforcement demands, they would be in violation of their stated policy.
user.home-info.postal
". The P3P
1.1 base data schema specifies a number of data sets.DATASCHEMA
element. P3P 1.1 defines a standard data schema
called the P3P base data schema.Identified datais information in a record or profile that can reasonably be tied to an individual, as defined in Section 1.3
Locating a P3P policy is one of the first steps in the operation of the P3P protocol. Services use policy references to state what policy applies to a specific URI or set of URIs. User agents use policy references to locate the privacy policy that applies to a Web resource, so that they can process that policy for the benefit of their user.
Policy references are used extensively as a performance optimization. P3P policies are typically several kilobytes of data, while a URI that references a privacy policy is typically less than 100 bytes. In addition to the bandwidth savings, policy references also reduce the need for computation: policies can be uniquely associated with URIs, so 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.
A policy reference file is used to associate P3P policies with certain regions of URI-space. The policy reference file is an XML with namespaces (see [XML] and [XML-Name]) 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.The policy reference file is used to make any or all of the following statements:
All of these statements are made in the body of the policy reference file.
This section describes the mechanisms used to indicate the location of a policy reference file. Detailed syntax is also given for the supported mechanisms.
The location of the policy reference file can be indicated using one of four mechanisms. The policy reference file
link
tag, orlink
tag, orNote that if user agents support retrieving HTML (resp. XHTML) content over HTTP, they MUST handle mechanisms 1, 2 and 3 (resp. 4) listed above interchangeably. See also the requirements for non-ambiguity.
Policies are applied at the level of resources. A "page" from the user's perspective may be composed of multiple HTTP resources; each may have its own P3P policy associated with it. As a practical note, however, placing many different P3P policies on different resources on a single page may make rendering the page and informing the user of the relevant policies difficult for user agents. Additionally, services are recommended to 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.
For a user agent to process the policy that applies to a given resource, it must locate the policy reference file for that resource, fetch the policy reference file, parse the policy reference file, fetch any required P3P policies, and then parse the P3P policy or policies.
This document does not specify how P3P policies may be associated with Web resources retrieved by means other than HTTP. However, it does not preclude future development of mechanisms for associating P3P policies with resources retrieved using other protocols. Furthermore, additional methods of associating P3P policies with HTTP resources may be developed in the future.
Web sites using P3P MAY (and, are strongly encouraged to) place a policy
reference file in a "well-known" location. To do this, a policy reference
file would be made available on the site at the path
/w3c/p3p.xml
.
Note that sites are not required to use this mechanism; however, by using this mechanism, sites can ensure that their P3P policy will be accessible to user agents before any other resources are requested from the site. This will reduce the need for user agents to access the site using safe zone practices. Additionally, if a site chooses to use this mechanism, the policy reference file located in the well-known location is not required to cover the entire site. For example, sites where not all of the content is under the control of a single organization MAY choose not to use this mechanism, or MAY choose to post a policy reference file which covers only a limited portion of the site.
Use of the well-known location for a policy reference file does not preclude use of other mechanisms for specifying a policy reference file. Portions of the site MAY use any of the other supported mechanisms to specify a policy reference file, so long as the non-ambiguity requirements are met.
For example, imagine a shopping-mall Web site run by the MallExample
company. On their Web site (mall.example.com
), companies
offering goods or services at the mall would get a company-specific subtree
of the site, perhaps in the path
/companies/company-name
. The MallExample company may
choose to put a policy reference file in the well-known location which covers
all of their site except the /companies
subtree. Then if the
ShoeStoreExample company has some content in
/companies/shoestoreexample
, they could use one of the other
mechanisms to indicate the location of a policy reference file covering their
portion of the mall.example.com
site.
One case where using the well-known location for policy reference files is
expected to be particularly useful is in the case of a site which has divided
its content across several hosts. For example, consider a site which uses a
different logical host for all of its Web-based applications than for its
static HTML content. The other mechanisms allowed for specifying the location
of a policy reference file require that some URI on the host being accessed
must be fetched to locate the policy reference file. However, the well-known
location mechanism has no such requirement. Consider the example of an HTML
form located on www.example.com
. Imagine that the action URI on
that form points to server cgi.example.com
. The policy reference
file that covers the form is unable to make any statements about the action
URI that processes the form. However, the site administrator publishes a
policy reference file at http://cgi.example.com/w3c/p3p.xml
that
covers the action URI, thus enabling a user agent to easily locate the P3P
policy that applies to the action URI before submitting the form contents.
Any document retrieved by HTTP MAY point to a policy reference file
through the use of a new response header, the P3P
header ([P3P-HEADER]). If a site is using P3P headers, it
SHOULD include this on responses for all appropriate request methods,
including HEAD
and OPTIONS
requests.
The P3P header gives one or more comma-separated directives. The syntax follows:
| [1] | p3p-header |
= |
`P3P: ` p3p-header-field *(`,` p3p-header-field) |
| [2] | p3p-header-field |
= |
policy-ref-field | compact-policy-field | extension-field |
| [3] | policy-ref-field |
= |
`policyref="` URI-reference `"` |
| [4] | extension-field |
= |
token [`=` (token | quoted-string) ] |
Here, URI-reference is
defined as per RFC
3986 [URI], token and
quoted-string are defined by [HTTP1.1]. |
In keeping with the rules for other HTTP headers, the name of the P3P header may be written with any casing. The contents should be specified using the casing precisely as specified in this document.
The policyref
directive gives a URI which specifies the
location of a policy reference file which may reference the P3P policy
covering the document that pointed to the reference file, and possibly others
as well. When the policyref
attribute is a relative URI, that
URI is interpreted relative to the request URI. Note that fetching the URI
given in the policyref
directive MAY result in a 300-class HTTP
return code (redirection); user agents MUST interpret those redirects with
normal HTTP semantics. Services should note, of course, that use of redirects
will increase the time required for user agents to find and interpret their
policies. The policyref
URI MUST NOT be used for any other
purpose beyond locating and referencing P3P policies.
The compact-policy-field
is used to specify "compact
policies". This is described in Section 4.
User agents which find unrecognized directives (in the
extension-field
s) MUST ignore the unrecognized directives. This
is to allow easier deployment of future versions of P3P.
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 P3P
header pointing to the
policy of the resource.
HTTP/1.1 200 OK P3P: policyref="http://catalog.example.com/P3P/PolicyReferences.xml" Content-Type: text/html Content-Length: 7413 Server: CC-Galaxy/1.3.18
link
TagServers MAY serve HTML content with embedded link
tags (cf.
[HTML]) that indicate the location of the relevant P3P
policy reference file. This use of P3P does not require any change in the
server behavior.
The link
tag encodes the policy reference information that
could be expressed using the P3P
header. The link
tag takes the following form (here, we just produce one possible ABNF format
for the link tag, and suppose the [HTML] syntax rules can
be used when using such a tag into an HTML file):
| [5] | p3p-link-tag |
= |
`<link rel="P3Pv1" href="` URI `">` |
Here, URI is defined as per RFC 3986 [URI]. |
When the href
attribute is a relative URI, that URI is
interpreted relative to the request URI.
In order to illustrate with an example the use of the link
tag, we consider the policy reference expressed in Example 2.1 using HTTP headers. That example can
be equivalently expressed using the link tag with the following piece of
HTML:
<link rel="P3Pv1" href="http://catalog.example.com/P3P/PolicyReferences.xml">
Finally, note that since the p3p-link-tag
is embedded in an
HTML document, its character encoding will be the same as that of the HTML
document. In contrast to P3P policy and policy reference documents (see section 2.3 and section 3
below), the p3p-link-tag
need not be encoded using [UTF-8]. Note also that the link
tag is not
case sensitive.
link
tagCorrespondingly to the HTML link
tag, P3P also supports XHTML
(cf. [XHTML-MOD]). Servers MAY serve XHTML content
that, using the XHTML Link Module (cf. Section
5.19 of [XHTML-MOD]), indicates the location of
the relevant P3P policy reference file with an embedded XHTML
link
tag. Like in the HTML case, an XHTML link
tag
can be used to encode the policy reference information that could be
expressed using the P3P
header, by:
rel
attribute to "P3Pv1
"href
attribute to the URI of the relevant P3P
policy reference fileThe mechanisms described here MAY be used for HTTP transactions over any underlying protocol. This includes plain-text HTTP over TCP/IP connections or encrypted HTTP over SSL connections, as well as HTTP over any other communications protocol designers wish to implement.
URIs MAY contain network port numbers, as specified in RFC 3986 [URI]. For the purposes of P3P, different ports on a single host MUST be considered to be separate "sites". Thus, for example, the policy reference file at the well-known location for www.example.com on port 80 (http://www.example.com/w3c/p3p.xml) would not give any information about the policies which apply to www.example.com when accessed over SSL (as the SSL communication would take place on a different port, 443 by default).
This document does not specify how P3P policies may be associated with resources retrieved by means other than HTTP. However, it does not preclude future development of mechanisms for associating P3P policies with resources retrieved over other protocols. Furthermore, additional methods of associating P3P policies with resources retrieved using HTTP may be developed in the future.
This section explains the contents of policy reference files in detail.
Consider the case of a Web site wishing to make the following statements:
/P3P/Policies.xml#first
applies to the entire
site, except resources whose paths begin with /catalog
,
/cgi-bin
, or /servlet
./P3P/Policies.xml#second
applies to all
resources whose paths begin with /catalog
./P3P/Policies.xml#third
applies to all
resources whose paths begin with /cgi-bin
or
/servlet
, except for /servlet/unknown
./servlet/unknown
.These statements can be represented by the following XML:
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <EXPIRY max-age="172800"/> <POLICY-REF about="/P3P/Policies.xml#first"> <INCLUDE>/*</INCLUDE> <EXCLUDE>/catalog/*</EXCLUDE> <EXCLUDE>/cgi-bin/*</EXCLUDE> <EXCLUDE>/servlet/*</EXCLUDE> </POLICY-REF> <POLICY-REF about="/P3P/Policies.xml#second"> <INCLUDE>/catalog/*</INCLUDE> </POLICY-REF> <POLICY-REF about="/P3P/Policies.xml#third"> <INCLUDE>/cgi-bin/*</INCLUDE> <INCLUDE>/servlet/*</INCLUDE> <EXCLUDE>/servlet/unknown</EXCLUDE> </POLICY-REF> </POLICY-REFERENCES> </META>
Note this example also includes via EXPIRY
a relative expiry time in the
document (cf. Section <IP_ADDRESS>.2).
This section defines the syntax and semantics of P3P policy reference files. All policy reference files MUST be encoded using [UTF-8]. P3P servers MUST encode their policy reference files using this syntax.
A policy reference file has the META
element as root. It may
contain multiple POLICY-REF
elements. If it does contain more
than one element, they MUST be processed by user agents in the order given in
the file. When a user agent is attempting to determine what policy applies to
a given URI, it MUST use the first POLICY-REF
element in the
policy reference file which applies to that URI.
Note that each POLICY-REF
may contain multiple
INCLUDE
, EXCLUDE
, METHOD
,
COOKIE-INCLUDE
, and COOKIE-EXCLUDE
elements and
that all of these elements within a given POLICY-REF
MUST be
considered together to determine whether the POLICY-REF
applies
to a given URI. Thus, it is not sufficient to find an INCLUDE
element that matches a given URI, as EXCLUDE
or
METHOD
elements may serve as modifiers that cause the
POLICY-REF
not to match.
Policy reference files make statements about what policy applies to a
given URI. Policy reference files support a simple wildcard character to
allow making statements about regions of URI-space. The character asterisk
('*
') is used to represent a sequence of 0 or more of any
character. No other special characters (such as those found in regular
expressions) are supported.
Note that since the asterisk is also a legal character in URIs ([URI]), some special conventions have to be followed when encoding such "extended URIs" in a policy reference file:
*
's in URIs MUST be escaped in policy
reference files (i.e., they MUST be represented as
"%2A
"). Any '*
' present in a URI within a
policy reference file will be taken as representing the asterisk
wildcard character.*
' present as the
asterisk wildcard character.URI escaping and un-escaping is very much dependent on the actual scheme used, and might even differ between individual components within a single scheme, so no simple rule for which characters need to be escaped can be given here. Please refer directly to [URI] for details on the standard escaping process. Note that P3P user agents MAY ignore any URI pattern that does not conform to [URI].
The wildcard character MAY be used in the INCLUDE
and
EXCLUDE
elements, in the COOKIE-INCLUDE
and
COOKIE-EXCLUDE
elements, and in the HINT
element.
META
and POLICY-REFERENCES
elements<META>
META
element contains a complete policy reference
file. Optionally, one POLICIES
element can follow.
META
can also contain one or more one or more EXTENSION
elements (cf. section 3.5), as well as an xml:lang
attribute (see section 2.4.2), to indicate the
language in which its content is expressed.<POLICY-REFERENCES
>POLICY-REF
(policy
reference) elements. It MAY also contain one EXPIRY
element (indicating
their expiration time), one or more HINT
element, and one or more EXTENSION
element (cf. section 3.5).| [6] | prf |
= |
`<META xmlns="http://www.w3.org/2002/01/P3Pv1"` [xml-lang] `>` *extension policyrefs [policies] *extension "</META>" |
| [7] | policyrefs |
= |
"<POLICY-REFERENCES>" [expiry] *policyref *hint *extension "</POLICY-REFERENCES>" |
Here PCDATA is defined in [XML]. |
EXPIRY
elementIt is desirable for servers to inform user agents about how long they can use the claims made in a policy reference file. By enabling clients to cache the contents of a policy reference file, it reduces the time required to process the privacy policy associated with a Web resource. This also reduces load on the network. In addition, clients that don't have a valid policy reference file for a URI will need to use "safe zone" practices for their requests. If clients have policy reference files that they know are still valid, then they can make more informed decisions on how to proceed.
In order to achieve these benefits, policy reference files SHOULD contain
an EXPIRY
element, which indicates the lifetime of the policy
reference file. If the policy reference file does not contain an
EXPIRY
element, then it defaults to 24-hour lifetime.
The lifetime of a policy reference file tells user agents how long they can rely on the claims made in the policy reference file. By setting the lifetime of a policy reference file, the publishing site agrees that the policies mentioned in the policy reference file are appropriate for the lifetime of the policy reference file. For example, if a policy reference file has a lifetime of 3 days, then a user agent need not reload that file for 3 days, and can assume that the references made in that policy reference file are good for 3 days. 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 different policy references is to use separate policy reference files.
The same mechanism used to indicate the lifetime of a policy reference
file is also used to indicate the lifetime of a P3P policy. Thus P3P
POLICIES
elements SHOULD have an EXPIRY
element
associated with them as well. This lifetime applies to all P3P policies
contained within that POLICIES
element. If there is no
EXPIRY
element associated with a P3P policy, then it defaults to
24-hour lifetime.
When picking a lifetime for policies and policy reference files, sites need to pick a lifetime which balances two competing concerns. One concern is that the lifetime ought to be long enough to allow user agents to receive significant benefits from caching. The other concern is that the site would like to be able to change their policy for new data collection without waiting for an extremely long lifetime to expire. It is expected that lifetimes in the range of 1-7 days would be a reasonable balance between these two competing desires. Sites also need to remember the policy update requirements when updating their policies.
When a policy reference file has expired, the information in the policy reference file MUST NOT be used by a user agent until that user agent has successfully revalidated the policy reference file, or has fetched a new copy of the policy reference file.
Note that while user agents are not obligated to re-validate policy reference files or policy files that have not expired, they MAY choose to re-validate those files before their expiry period has passed in order to reduce the need for using "safe zone" practices. A valid P3P user agent implementation does not need to contain a cache for policies and policy reference files, though the implementation will have better performance if it does.
EXPIRY
elementThe EXPIRY
element can be used in a policy reference file
and/or in a POLICIES
element to state how long the policy
reference file (or policies) remains valid. The
expiry is given as either an absolute expiry time, or a relative expiry time.
An absolute expiry time is a time, given in GMT, until which the policy
reference file (or policies) is valid. A relative
expiry time gives a number of seconds for which the policy reference file (or
policies) is valid. This expiry time is relative to
the time the policy reference file (or policies) was
requested or last revalidated by the client. This computation MUST be done
using the time of the original request or revalidation, and the current time,
with both times generated from the client's clock. Revalidation is defined in
section 13.3 of [HTTP1.1].
The minimum amount of time for any relative expiry time is 24 hours, or 86400 seconds. Any relative expiration time shorter than 86400 seconds MUST be treated as being equal to 86400 seconds in a client implementation. If a client encounters an absolute expiration time that is in the past, it MUST act as if NO policy reference file (or policy) is available. See section 2.4.7 "Absence of Policy Reference File" for the required procedure in such cases.
| [8] | expiry |
= |
"<EXPIRY" (absdate|reldate) "/>" |
| [9] | absdate |
= |
`date="` HTTP-date `"` |
| [10] | reldate |
= |
`max-age="` delta-seconds `"` |
| Here, HTTP-date is defined in section 3.3.1 of [HTTP1.1], and delta-seconds is defined in section 3.3.2 of [HTTP1.1]. |
In a real-world network, there may be caches which will cache the contents of policies and policy reference files. This is good for increasing the overall network performance, but may have deleterious effects on the operation of P3P if not used correctly. There are two specific concerns:
HTTP 1.1 [HTTP1.1] contains powerful cache-control mechanisms to allow clients to place requirements on the operations of network caches; these mechanisms can resolve the problems mentioned above. The specific method will be discussed below.
HTTP 1.0, however, does not provide those more sophisticated cache control
mechanisms. An HTTP 1.0 caching proxy will, in all likelihood, compute a
cache lifetime for the policy reference file (or policies) based on the
file's last-modified date; the resulting cache lifetime could be
significantly longer than the lifetime specified by the EXPIRY
element. The caching proxy could then serve the policy reference file (or
policies) to clients beyond the lifetime in the EXPIRY
; the
result would be that user-agents would receive a useless policy reference
file (or policies).
The second problem with an HTTP 1.0 caching proxy is that a user agent has no way to know how long the reference file may have been stored by the caching proxy. If the policy reference file (or policies) relies on relative expiry, 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.
Thus, if a user agent is requesting a policy reference file or a policy, and does not know for certain that there are no HTTP 1.0 caches in the path to the origin server, then the request MUST force an end-to-end revalidation. This can be done with the Pragma: no-cache HTTP request-header. Note that neither HTTP nor P3P define a way to determine if there is a HTTP 1.0-compliant cache in any given network path, so unless the user agent has this information derived from an outside source, it MUST force the end-to-end revalidation.
If the user agent has some way to know that all caches in the network path to the origin server are compliant with HTTP 1.1 (or that there are no caches in the network path to the origin server), then the client MAY do the following instead of forcing an end-to-end revalidation:
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 re-validating the policy reference file before continuing with the request.
The following situations have their semantics specifically defined:
EXPIRY
element, the first one takes precedence for determining the lifetime of
the policy reference file.POLICY-REF
elementA policy reference file may refer to multiple P3P policies, specifying
information about each. The POLICY-REF
element 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 (and cookies) that each policy covers.
POLICY-REF
about
(mandatory
attribute)name
attribute), and the URI part denotes the URI where
the policy resides (a policy file, or a policy reference file, see Section 3.2). If this is a relative URI reference,
it is interpreted relative to the URI of the policy reference file it
resides in.| [11] | policy-ref |
= |
`<POLICY-REF about="` URI-reference `">` *include *exclude *cookie-include *cookie-exclude *method-element *extension `</POLICY-REF>` |
Here, URI-reference is defined as per RFC 3986 [URI]. |
INCLUDE
and EXCLUDE
elementsEach INCLUDE
or EXCLUDE
element specifies one
local URI or set of local URIs. A set of URIs is specified if the wildcard character '*' is used in the
URI-pattern. These elements are used to specify the portion of the Web site
that is covered by the policy referenced by the enclosing
POLICY-REF
element.
When INCLUDE
(and optionally, EXCLUDE
) elements
are present in a POLICY-REF
element, it means that the policy
specified in the about
attribute of the POLICY-REF
element applies to all the URIs at the requested host corresponding to the
local-URI(s) matched by any of the INCLUDE
s, but not matched by
an EXCLUDE
element.
A policy referenced in a policy reference file can be applied only to URIs
on the DNS (Domain Name System) host that references it. Thus, for example, a
policy reference file at the well-known location of host www.example.com can
apply policies only to resources on www.example.com. However, if
foo.example.com includes a P3P HTTP header in its responses that references a
policy reference file on bar.example.com, that policy reference file would be
applied to resources on foo.example.com (not bar.example.com or
www.example.com). The same policy reference file might be referenced in P3P
HTTP headers sent by multiple hosts, in which case it may be applied to each
host that references it. The INCLUDE
and EXCLUDE
elements MUST specify URI patterns relative to the root of the DNS host to
which they are applied. This requirement does NOT apply to the location of
the P3P policy file (the about attribute on the POLICY-REF
element).
If a METHOD
element (section
<IP_ADDRESS>) specifies one or more methods for an enclosing policy reference,
it follows that all methods not mentioned are consequently
not covered by this policy. In the case that this is the only policy
reference for a given URI prefix, user agents MUST assume that NO policy is
in effect for all methods NOT mentioned in the policy reference file. It is
legal but pointless to supply a METHOD
element without any
INCLUDE
or COOKIE-INCLUDE
elements.
It is legal, but pointless, to supply an EXCLUDE
element
without any INCLUDE
elements; in that case, the
EXCLUDE
element MUST be ignored by user agents.
Note that the set of URIs specified with INCLUDE
and
EXCLUDE
does not include cookies that might be set or replayed
when requesting one of such URIs: in order to associate policies with
cookies, the COOKIE-INCLUDE
and
COOKIE-EXCLUDE
elements are needed.
| [12] | include |
= |
"<INCLUDE>" relativeURI "</INCLUDE>" |
| [13] | exclude |
= |
"<EXCLUDE>" relativeURI "</EXCLUDE>" |
Here, relativeURI is defined as per RFC 3986 [URI], with the addition that the '* '
character is to be treated as a wildcard, as defined in section <IP_ADDRESS>.2. |
HINT
elementPolicy reference hints are a performance optimization that can be used
under certain conditions. A site may declare a policy reference for itself
using the well-known location, the P3P response header, or the HTML/XHTML
link
tag. It MAY further provide a hint to additional policy
references, such as those declared by other sites.
For example, an HTML page might hint at policy references for its hyper-links, embedded content, and action URIs. User agents MAY use the hint mechanism to discover policy reference files before requesting the affected URIs when the policy references are not available from the well-known location.
User agents which use hints to retrieve policies MUST NOT apply them to any site other than the one which contains the hinted policy reference file.
Any policy reference file MAY contain zero or more policy reference hints.
Each hint is contained in a HINT
element with two attributes,
scope
and path
.
The scope
attribute is used to specify a URI scheme and
authority to which the hinted policy reference can be applied. If the
authority component (cf. [URI]) is a server component
(e.g., a host name or IP address) the host part of the authority MAY begin
with a wildcard, as defined in Section
<IP_ADDRESS>.2. The scope
attribute MUST NOT contain a wildcard in
any other position, MUST be encoded according to the conventions in Section
<IP_ADDRESS>.2, and MUST NOT contain a path, query or fragment URI component.
Additionally, if the authority is a server, it SHOULD NOT contain a userinfo
part.
For example, legal values for scope
include:
http://www.example.com
http://www.example.com:81
http://*.example.com
ftp://ftp.example.org
The following are illegal values for the scope
attribute:
http://www.*.com
; the wildcard can only be at the
starthttp://www.example.com/
; the trailing slash is not
allowedwww.example.com
; the scheme must be stated*://www.example.com
; the scheme cannot contain a
wildcardhttp://www.example.com:*
; the port cannot contain a
wildcardThe path
attribute is used to locate the policy reference
file on the hinted site. It is a relative URI whose base is the URI scheme
and authority matched in the scope
attribute. The
path
attribute MUST NOT be an absolute URI, so that the policy
reference file is always retrieved from the same site that it is applied
to.
Example 2.3:
<HINT scope="http://www.example.org" path="/mypolicy/p3.xml" /> <HINT scope="http://www.example.net:81" path="/w3c/prf.xml" /> <HINT scope="http://*.shop.example.com" path="/w3c/prf.xml" />
| [14] | hint |
= |
`<HINT scope="` scheme ( `://` | `:/` ) authority `" path="` relativeURI `/>` |
Here, scheme , authority and
relativeURI are taken from RFC 2965 [STATE]. |
COOKIE-INCLUDE
and
COOKIE-EXCLUDE
elementsThe COOKIE-INCLUDE
and COOKIE-EXCLUDE
elements
are used to associate policies to cookies (cf. [COOKIES] and [STATE]).
A cookie policy MUST cover any data (within the scope of P3P)
that is stored in that cookie or linked via
that cookie. It MUST also reference all purposes associated with
data stored in that cookie or enabled by that cookie. In
addition, any data/purpose stored or linked
via a cookie MUST also be put in the cookie policy. In addition,
if that linked data is collected by HTTP, then the policy that
covers that GET
/POST
/whatever request
must cover that data collection. For example, when CatalogExample
asks customers to fill out a form with their name, billing, and
shipping information, the P3P policy that covers the form
submittal will disclose that CatalogExample collects this data
and explain how it is used. If CatalogExample sets a cookie so
that it can recognize its customers and observe their behavior on
its Web site, it would have a separate policy for this cookie.
However, if this cookie is also linked to the user's name,
billing, and shipping information -- perhaps so CatalogExample
can generate custom catalog pages based on where the customer
lives -- then that data must also be disclosed in the cookie
policy.
For the purpose of this specification, state management mechanisms use
either SET-COOKIE
or SET-COOKIE2
headers, and
cookie-namespace is defined as the value of the NAME, VALUE, Domain and Path
attributes, specified in [COOKIES] and [STATE].
Each COOKIE-INCLUDE
or COOKIE-EXCLUDE
element
can be used to match (similarly to INCLUDE
and
EXCLUDE
) the NAME, VALUE, Domain and Path components of a
cookie, expressing the cookies which are covered by the policy specified by
the about
attribute when the cookies are set from the resources
on the Web site where the policy reference file resides:
COOKIE-INCLUDE
(resp.
COOKIE-EXCLUDE
)name
,
value
, domain
and path
attributesname
value
domain
path
If the value of the domain
attribute is set to the dot
character (".
"), the domain will match only cookies that omit
the domain
attribute (and thus have domain equivalent to the
request host as per RFC
2965 ([STATE]).
Cookies that omit the path attribute have the default path of the request
URI that generated the set-cookie response as per RFC 2965 [STATE]. The path
attribute of a
COOKIE-INCLUDE
should be matched against this default value if a
cookie omits the path
attribute.
All four attributes are optional. If an attribute is absent, the
COOKIE-INCLUDE
(resp. COOKIE-EXCLUDE
) will match
cookies that have that attribute set to any value.
When COOKIE-INCLUDE
(and optionally,
COOKIE-EXCLUDE
) elements are present in a
POLICY-REF
element, the policy specified in the
about
attribute of the POLICY-REF
element applies
to every cookie that is matched by any COOKIE-INCLUDE
's, and not
matched by a COOKIE-EXCLUDE
element.
User agents MUST interpret COOKIE-INCLUDE
and
COOKIE-EXCLUDE
elements in a policy reference file to determine
the policy that applies to cookies set by or replayed to the host to which
the policy reference file applies. While the domain attribute of a
COOKIE-INCLUDE
may match more broadly (for example, if the
domain attribute is omitted it defaults to matching any domain value), user
agents MUST limit their application of the policy to domains that could be
legally used in a cookie set by the host to which the policy reference file
applies. For example, if abc.xyz.example.com declares a policyref with
<COOKIE-INCLUDE domain="*.xyz.*ple.com"/>
, this would be
matched to cookies with domains such as .abc.xyz.example.com and
.xyz.example.com, but not .example.com or .xyz.sample.com.
A P3P policy can be associated with a cookie by the host that set that
cookie as well as by any or all of the hosts to which it might be replayed. A
user agent MAY fetch a cookie policy at the time a cookie is set and apply it
later when the cookie is replayed, perhaps to other hosts in the domain. A
user agent MAY request a policy reference file from a host before replaying a
cookie to that host, and if the policy reference file contains an appropriate
COOKIE-INCLUDE
, a policy will be applied to that cookie even if
the cookie was not set by that host. Any host to which the cookie may be
replayed MUST be able to honor all the policies associated with the cookie,
regardless of whether that host declares a policy for that cookie. Thus sites
that set cookies that may be replayed to multiple hosts within a domain need
to coordinate to make sure all the hosts can follow the declared policy. In
addition, sites should be cautious with their use of wildcards to make sure
that they do not inadvertently apply a policy to cookies to which it should
not be applied (including previously set cookies that are still in use and
cookies set by other hosts in the domain).
The policy that applies to a cookie applies until the policy expires, even if the associated policy reference file expires prior to policy expiry (but after the cookie was set). If the policy associated with a cookie has expired, then the user agent SHOULD reevaluate the cookie policy before sending the cookie. In addition, user agents MUST use only non-expired policies and policy reference files when evaluating new set-cookie events.
User agents that evaluate cookie policies SHOULD perform this evaluation *and its resultant behavior* before setting a cookie so that the cookie can be discarded without being set if that is what is dictated by the user's preferences.
Example 2.4 states that /P3P/Policies.xml#first
applies to
all cookies.
Example 2.4:
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/P3P/Policies.xml#first"> <COOKIE-INCLUDE name="*" value="*" domain="*" path="*"/> </POLICY-REF> </POLICY-REFERENCES> </META>
Example 2.5 states that /P3P/Policies.xml#first
applies to
all cookies, except cookies with the cookie name value of
"obnoxious-cookie
", a domain value of
".example.com
", and a path value of "/
", and that
/P3P/Policies.xml#second
applies to all cookies with the cookie
name of "obnoxious-cookie
", a domain value of
".example.com
", and a path value of "/
".
Example 2.5:
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/P3P/Policies.xml#first"> <COOKIE-INCLUDE name="*" value="*" domain="*" path="*"/> <COOKIE-EXCLUDE name="obnoxious-cookie" value="*" domain=".example.com" path="/"/> </POLICY-REF> <POLICY-REF about="/P3P/Policies.xml#second"> <COOKIE-INCLUDE name="obnoxious-cookie" value="*" domain=".example.com" path="/"/> </POLICY-REF> </POLICY-REFERENCES> </META>
| [15] | cookie-include |
= |
"<COOKIE-INCLUDE" [` name="` token `"`] ; matches the cookie's NAME [` value="` token `"`] ; matches the cookie's VALUE [` domain="` token `"`] ; matches the cookie's Domain [` path="` token `"`] ; matches the cookie's Path "/>" |
| [16] | cookie-exclude |
= |
"<COOKIE-EXCLUDE" [` name="` token `"`] ; matches the cookie's NAME [` value="` token `"`] ; matches the cookie's VALUE [` domain="` token `"`] ; matches the cookie's Domain [` path="` token `"`] ; matches the cookie's Path "/>" |
Here, token , NAME ,
VALUE , Domain and Path are
defined as per RFC
2965 [STATE], with the addition that the
'* ' character is to be treated as a wildcard, as defined
in section <IP_ADDRESS>.2. |
Note that [STATE] states default values for the
domain and path attributes of cookies: these should be used in the comparison
if those attributes are not found in a specific cookie. Also, conforming to
[STATE], if an explicitly specified
Domain
value does not start with a full stop (".
"),
the user agent MUST prepend a full stop for it; and, note that every
Path
begins with the "/
" character.
METHOD
elementBy 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/Policies.xml#first
applies to all
resources whose paths begin with /docs/
for GET
and
HEAD
methods, while /P3P/Policies.xml#second
applies for PUT
and DELETE
methods, the following
policy reference would be written:
Example 2.6:
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/P3P/Policies.xml#first"> <INCLUDE>/docs/*</INCLUDE> <METHOD>GET</METHOD> <METHOD>HEAD</METHOD> </POLICY-REF> <POLICY-REF about="/P3P/Policies.xml#second"> <INCLUDE>/docs/*</INCLUDE> <METHOD>PUT</METHOD> <METHOD>DELETE</METHOD> </POLICY-REF> </POLICY-REFERENCES> </META>
Note that HTTP requires the same behavior for GET
and
HEAD
requests, thus it is inappropriate to specify different P3P
policies for these methods. The syntax for the METHOD
element
is:
| [17] | method-element |
= |
`<METHOD>` Method `</METHOD>` |
Here, Method is defined in the section
5.1.1 of [HTTP1.1]. |
Finally, note that the METHOD
element is designed to be used
in conjunction with INCLUDE
or COOKIE-INCLUDE
elements. A METHOD
element by itself will never apply a
POLICY-REF
to a URI.
This section describes a method to allow user agents to recognize when hosts in different domains are owned by the same entity or entities acting as agents for one another. User agents may use this information when applying privacy preferences, particularly to avoid implementation issues encountered when more stringent privacy preferences are applied to domains that are deemed to be owned by third-parties. See [Coremetrics]
OUR-HOST
ExtensionThe OUR-HOST
element allows sites to declare hosts that are
owned by the entity in the associated policy or that are acting as agents of
that entity. User agents may use this extension to distinguish between such a
host and actual third-party hosts.
The attribute name
is a host name qualifier that can be a
full individual host/domain name (e.g. www.example.com) or a wildcard
qualifier describing a set of hosts/domains.
our-hosts-extension = `<EXTENSION optional="yes">` *[our-host] `</EXTENSION>` our-host = `<OUR-HOST xmlns="http://www.w3.org/2006/01/P3Pv11"` [`name="` authority `"`] `/>`
Here, authorityis defined as per RFC 3986 [URI], with the addition that the '*' character is to be treated as a wildcard, as defined in section <IP_ADDRESS>.2.
The OUR-HOST
element is declared in the
POLICY-REF
element. For URIs covered by the associated policy,
the user agent can encounter other hosts in different domains serving
embedded content, link, or action requests. The user agent may consider such
a host to be owned by the same entity or one of its agents if its URI matches
an associated OUR-HOST
entry. Any number of
OUR-HOST
elements can be declared inside a
POLICY-REF
element.
Embedded content is considered to be any content that is retrieved during
the processing of the current document, such as images, documents in frames,
script files, etc. Content embedded more than 1 level deep (e.g. an image
inside a frame) is still considered embedded content and the
OUR-HOST
declarations at the top-level may still apply.
Any relationships inferred by this mechanism are valid only in the context
for which they were discovered -- this is not a mechanism for declaring
globally that two hosts have a relationship in all contexts. By extension,
the relationships are not transitive. Suppose two distinct hosts A and C are
matched by OUR-HOST
entries in a policy reference file for host
B. Even if the same policy applies to both, nothing may be inferred about the
relationship between A and C for use in other contexts. The relationships are
not transitive even in the case of multi-level embedded content -- the
top-level host must declare OUR-HOST
relationships for all
levels of embedded content.
In this example, example.com and example.net are owned by the same
company. The example.net file has an OUR-HOST
declaration for
hosts in the example.com domain.
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/p3p/policy.xml#corporate"> <INCLUDE>/*</INCLUDE> <COOKIE-INCLUDE name="*" value="*"/> <EXTENSION> <OUR-HOST name="*.example.com" xmlns="http://www.w3.org/2006/01/P3Pv11" /> </EXTENSION> </POLICY-REF> </POLICY-REFERENCES> </META>
The following example.com policy reference file shows two policies and two
OUR-HOST
declarations. The first declaration is for hosts in the
example.net domain and applies to all URIs except for ones that begin with
"/surveys/". The second OUR-HOST
declaration is for hosts in the
example.org domain and applies to all URIs that begin with "/surveys/". Since
the example.net domain is not declared with this policy reference, user
agents can not verify a relationship between example.com and example.net
hosts for the survey URIs.
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/p3p/policy.xml#corporate"> <INCLUDE>/*</INCLUDE> <EXCLUDE>/surveys/*</EXCLUDE> <EXTENSION> <OUR-HOST name="*.example.net" xmlns="http://www.w3.org/2006/01/P3Pv11" /> </EXTENSION> </POLICY-REF> <POLICY-REF about="/p3p/policy.xml#surveys"> <INCLUDE>/surveys/*</INCLUDE> <EXTENSION> <OUR-HOST name="*.example.org" xmlns="http://www.w3.org/2006/01/P3Pv11" /> </EXTENSION> </POLICY-REF> </POLICY-REFERENCES> </META>
Browsers may cache the policy reference file based on its EXPIRY element.
The expiration information associated with that element should also be
considered to apply to the OUR-HOST
declarations; i.e. that
information may be cached along with the policy reference information.
The use of the OUR-HOST
extension is optional. This extension
provides more information that user agents may use in applying users' privacy
preferences.
If a user agent allows a cookie to be set based on a relationship
established by OUR-HOST
declarations, it should verify that such
a relationship exists at cookie playback time, and not send the cookie if
not. When not using compact policies, such verification implies re-fetching
an expired policy reference file and evaluating its OUR-HOST
declarations.
Hosts may return an special token ("OHO:") in the P3P compact policy
header to indicate OUR-HOST
relationships. This token is
followed by a comma-delimited list of hostname qualifiers that describe hosts
that are owned by the same entity as the current host or that are acting as
agents of the current host. This list is equivalent to the
OUR-HOST
declarations in the policy reference file, but it may
be applied when using compact policies. In the example above, example.com
could return the header:
P3P: CP="NON DSP ADM DEV PSD IVDo OUR IND STP PHY PRE NAV UNI OHO:*.example.org"
Hosts returning embedded content are not required to declare a
corresponding OHO
token in their compact policies.
This token is optional and may be ignored by user agents. The syntax for the token is as follows:
compact-our-host = `OHO:` authority *(`,` authority)
Here, authority
is defined as per RFC 3986 [URI], with the
addition that the '*' character is to be treated as a wildcard, as defined in
section <IP_ADDRESS>.2.
A policy reference file specifies the policy which applies to a given URI.
In other words, the indicated policy describes all effects of dereferencing
the given URI (in some cases, with the appropriately specified
METHOD
).
There is a general rule which describes what it means for a P3P policy to
cover a URI: the referenced policy MUST cover actions that the user's
client software is expected to perform as a result of requesting that
URI. Obviously, the policy must describe all data collection performed by
site as a result of processing the request for the URI. Thus, if a given URI
is covered for terms of GET
requests, then the policy given by
the policy reference file MUST describe all data collection performed by the
site when that URI is dereferenced. Likewise, if a URI is covered for
POST
requests, then any data collection that occurs as a result
of POSTing a form or other content to that URI MUST be described by the
policy.
The concept of "actions that the client software is expected to perform" includes the setting of client-side cookies or other state-management mechanisms invoked by the response. If executable code is returned when a URI is requested, then the P3P policy covering that URI MUST cover certain actions which will occur when that code is executed. The covered actions are any actions which could take place without the user explicitly invoking them. If explicit user action causes data to be collected, then the P3P policy covering the URI for that action would disclose that data collection.
Some specific examples:
Forms deserve special consideration, as they often link to CGI scripts or
other server-side applications in their action URIs (the action URI
is the URI given in the action attribute of the HTML
<FORM>
element, as defined in section 17.3 of [HTML]). It is often the case that those action URIs are
covered by a different policy than the form itself.
If a user agent is unable to find a matching include-rule for a given
action URI in the policy reference file that was referenced from the page, it
SHOULD assume that no policy is in effect. Under these
circumstances, user agents SHOULD check the well-known location on the host of the action
URI to attempt to find a policy reference file that covers the action URI. If
this does not provide a P3P policy to cover the action URI, then a user agent
MAY try to retrieve the policy reference file by using the HINT
mechanism on the action URI, and/or by
issuing a HEAD
request to the action URI before actually
submitting any data in order to find the policy in effect. Services SHOULD
ensure that server-side applications can properly respond to such
HEAD
requests and return the corresponding policy reference link
in the headers. In case the underlying application does not understand the
HEAD
request and no policy has been predeclared for the
action URI in question, user agents MUST assume that no policy is in
effect and SHOULD inform the user about this or take the corresponding
actions according to the user's preferences.
Note that services might want to make use of the
<METHOD>
element in order to declare policies for
server-side applications that only cover a subset of supported methods, e.g.,
POST
or GET
. Under such circumstances, it is
acceptable that the application in question only supports the methods given
in the policy reference file (e.g., PUT
requests need not be
supported). User agents SHOULD NOT attempt to issue a HEAD
request to an action URI if the relevant methods specified in the form's
method
attribute have been properly predeclared in the page's
policy reference file.
In some cases, different data is collected at the same
action URI depending on some selection in the form. For example, a search
service might offer to both search for people (by name and/or email) and
(arbitrary) images. Using a set of radio buttons on the form, a single
server-side application located at one and the same action URI handles both
cases and collects the required information necessary for the search. If a
service wants to predeclare the data collection practices of the server-side
application it MAY declare all of the data collection practices in a
single policy file (using a <INCLUDE>
declaration
matching the action URI). In this case, user agents MUST assume that all data
elements are collected under every circumstance. This solution offers the
convenience of a single policy but might not properly reflect the fact that
only parts of the listed data elements are collected at a time. Services
SHOULD make sure that a simple HEAD
request to the action URI
(i.e., without any arguments, especially without the value of the selected
radio button) will return a policy that covers all cases.
Note that if a form is handled through use of the GET
method,
then the action URI reflects the choice of form elements selected by the
user. In some cases, it will be possible to make use of the wildcard syntax
allowed in policy reference files to specify different policies for different
uses of the same form action-handler URI. Therefore, user agents MUST include
the query-string portion of URIs when making comparisons with
INCLUDE
and EXCLUDE
elements in policy reference
files.
User agents need to be able to determine unambiguously what policy applies to a given URI. Therefore, sites SHOULD avoid declaring more than one non-expired policy for a given URI. In some rare case sites MAY declare more than one non-expired policy for a given URI, for example, during a transition period when the site is changing its policy. In those cases, the site will probably not be able to determine reliably which policy any given user has seen, and thus it MUST honor all policies (this is also the case for compact policies, cf. Section 4.1 . Sites MUST be cautious in their practices when they declare multiple policies for a given URI, and ensure that they can actually honor all policies simultaneously.
If a policy reference file at the well-known location declares a non-expired policy for a given URI, this policy applies, regardless of any conflicting policy reference files referenced through HTTP headers or HTML/XHTML link tags.
If an HTTP response header includes references to more than one policy reference file, P3P user agents MUST ignore all references after the first one.
If an HTML (resp. XHTML) file includes HTML (resp. XHTML)
link
tag references to more than one policy reference file, P3P
user agents MUST ignore all references after the first one.
If a user agent discovers more than one non-expired P3P policy for a given
URI (for example because a page has both a P3P header and a link
tag that reference different policy reference files, or because P3P headers
for two pages on the site reference different policy reference files that
declare different policies for the same URI), the user agent MAY assume any
(or all) of these policies apply as the site MUST honor all of them.
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. Servers SHOULD return a
localized policy in response to an HTTP request with an HTTP
"Accept-Language
" header when a policy matching the given
language preferences is available.
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. Two policies (or two data schemas) are
taken to be identical if
Due to the use of the Accept-Language
mechanism, implementers
should take note that user agents may see different language versions of a
policy or policy reference file despite sending the same
Accept-Language
request header if a new language version of a
policy or data schema has been added.
Finally, language declarations can be also included directly within P3P
XML files: the POLICY
, POLICIES
, META
,
and DATASCHEMA
elements MAY take an xml:lang
attribute to indicate the language of any human-readable fields they contain
(xml:lang
is normatively defined in section 2.12 of [XML]).
| [18] | xml-lang |
= |
` xml:lang="` language `"` |
Here, language is a language identifier as
defined in [LANG]. |
Safe Zone
P3P defines a special set of "safe zone" practices, which SHOULD be used by all P3P-enabled user agents and services for the communications which take place as part of fetching a P3P policy or policy reference file. In particular, requests to the well-known location for policy reference files SHOULD be covered by these "safe zone" practices. Communications covered by the safe zone practices SHOULD have only minimal data collection, 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. Therefore safe-zone practices for user agents include the following requirements:
Referer
header in the
safe zoneAccept-Language
HTTP header in the
safe zone. Sending the correct Accept-Language
header will
allow fetching a P3P policy in the user's preferred natural language (if
available), but does expose a certain amount of information about the
identity of the user. User agents MAY wish to allow users to decide when
these headers should be sent.Safe-zone practices for servers include the following requirements:
Referer
header, cookies, user agent information, or other information unnecessary
for responding to requests in the safe zoneAccept-Language
HTTP
header as part of safe-zone operation, the server is free to choose any
of the available translationsNote that the safe zone 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 or policy reference file. Tracking down the source of a denial of service attack, for example, would be a legitimate reason to use this information.
P3P user agents MUST only render or act upon P3P policies and policy reference files that are well-formed XML.
P3P user agents SHOULD only render or act upon P3P policies and policy reference files that conform to the XML schema given in Appendix 5, and user agents SHOULD NOT rely upon any part of a policy or policy reference file that does not conform to this XML schema.
User agents MUST NOT locally modify a P3P policy or policy reference file in order to make it conform to the XML schema.
P3P policies and references to P3P policies SHOULD NOT 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 P3P does 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.
Note that when a Web site changes its P3P policy, the old policy applies to data collected when it was in effect. It is the responsibility of the site to keep records of past P3P policies and policy reference files along with the dates when they were in effect, and to apply these policies appropriately.
If a site wishes to apply a new P3P policy to previously collected data, it MUST provide appropriate notice and opportunities for users to accept the new policy that are consistent with applicable laws, industry guidelines, or other privacy-related agreements the site has made.
If no policy reference file is available for a given site, user agents MUST assume (an empty) policy reference file exists at the well-known location with a 24 hour expiry, and therefore if the user returns to the site after 24 hours, the user agent MUST attempt to fetch a policy reference file from the well-known location again. User agents MAY check the well-known location more frequently, or upon a certain event such as the user clicking a browser refresh button. Sites MAY place a policy reference file at the well-known location that indicates that no policy is available, but set the expiry such that user agents know they need not check every 24 hours.
User agents MAY asynchronously fetch and evaluate P3P policies. That is, P3P policies need not necessarily be fetched and evaluated prior to other HTTP transactions.This behavior may be dependent on the the user's preferences and the type of request being made. Until a policy is evaluated, the user agent SHOULD treat the site as if it has no privacy policy. Once the policy has been evaluated, the user agent SHOULD apply the user's preferences. To promote deterministic behavior, the user agent SHOULD defer application of a policy until a consistent point in time. For example, a Web browser might apply a user's preferences just after the user agent completes a navigation, or when confirming a form submission.
P3P 1.0 was
designed to associate XML-encoded privacy policies with URIs, sets of URIs,
or cookies. P3P 1.0 is well suited for use with HTML and XHTML pages
transmitted over [HTTP1.1]
or
[HTTP1.0]
. However, P3P 1.0 cannot
be used in situations where a request is not directed to a URI, for example,
some applications of Web Services
and SOAP. In addition, P3P 1.0
cannot be used in situations where policies apply to only a subset of the
content associated with a given URI. For example, while P3P 1.0 can be used
to apply a P3P policy to an entire form specified by XForms, it cannot be used to apply
the policy to only a single form field.
The P3P 1.1 Specification provides a new binding mechanism to allow for
increased granularity beyond the URI level and to allow policies to apply to
content not associated with a URI. The new mechanism takes the form of a
generic attribute (similar to xml:lang
) that
binds a P3P policy to an XML element.
A P3P policy referenced by the P3P generic attribute MUST apply to all data collection performed as a result of processing the elementcarrying the P3P Generic Attribute. The policy also MUST describe all data collection performed as a result of the processing of all subelements.
For all XML applications in which the P3P Generic Attribute is to be used, the attribute MUST be imported into the relevant XML schema.
If the element is re-used by mechanisms such as XInclude or the SVG <use> Element, the Policy applies also in the new context where the element is re-used. The policy is sticky to the element from which it is referenced.
The P3P Generic Attribute is designed for use in XML elements that describe interfaces, not XML elements that encode user data. Thus, it is meaningful to use the P3P Generic Attribute to associate a P3P policy with a blank form or form field. The semantics of such an association are that any data entered into the form will be processed in a manner consistent with the P3P policy. It is not meaningful to use the P3P Generic Attribute to associate a P3P policy with data a user has entered into a form.
The P3P Generic Attribute MUST NOT be used in applications, such as RDF, that do not have a tree structure because its semantics relies on the concept of subelements. In the case of RDF, one of the other three binding mechanisms described in 2. Referencing Policies may be used, as RDF makes use of URIs.
The P3P generic attribute takes a URI of a valid P3P 1.1 policy as
its value. If multiple policy elements are contained, a fragment must
be used to identify the applicable policy. The P3P generic attribute
MUST NOT reference a P3P Policy Reference File
.
| [19] | p3pattr |
= |
`p3pattr=`p3p11:p3p="` quoted-URI `"` `xmlns:p3p11="http://www.w3.org/2006/01/P3Pv11" ` |
Here is an example of how the P3P attribute might be used with WSDL.
<?xml version="1.0"?> <definitions xmlns="http://www.w3.org/2003/11/wsdl" xmlns:myns="http://example.org/myservice" xmlns:mytypes="http://example.org/myservice-types" xmlns:p3p11="http://www.w3.org/2006/01/P3Pv11" xmlns:soap="http://www.w3.org/2003/06/wsdl/soap12" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://example.org/myservice" > <documentation> Sample service definition showing the use of the P3P generic attribute </documentation> <types> <xs:import namespave='http://example.org/myservice'/> </types> <interface name="Interface"> <operation name="Operation" pattern="http://www.w3.org/2003/11/wsdl/in-out"> <input message="mytypes:commentReq"/> <output message="myntypes:commentResp"/> </operation> </interface> <binding name="Binding" interface="myns:Interface"> <soap:binding protocol="http://www.w3.org/2003/05/soap/bindings/HTTP/"/> </binding> <service name="Service" interface="myns:Interface" p3p11:p3p="http://example.com/p3p-pol3.xml#pol3" > <endpoint name="Endpoint1" binding="myns:binding"> <soap:address location="http://ws.example.org/myservice" /> </endpoint> </service> </definitions>
As an aid to sites deploying P3P, several example scenarios are presented, along with descriptions of how P3P is used on those sites.
Scenario 1: Web site basic.example.com uses a variety of images, all of which it hosts. It also includes some forms, which are all submitted directly to the site. This site can declare a single P3P policy for the entire site (or if different privacy policies apply to different parts of the site, it can declare multiple P3P policies). As long as all of the images and form action URIs are in directories covered by the site's P3P policy, user agents will automatically recognize the images and forms as covered by the site's policy.
Scenario 2: Web site busy.example.com uses a content
distribution network called cdn.example.com to host its images so as to
reduce the load on its servers. Thus, all of the images on the site have URIs
at cdn.example.com. CDN acts as an agent to Busy in this situation, and
collects no data other than log data. This log data is used only for Web site
and system administration in support of providing the services that Busy
contracted for. Busy's privacy policy applies to the images hosted by CDN, so
Busy uses the HINT
element in its policy reference file to point
to a suitable policy reference file at CDN, indicating that such images are
covered by example.com P3P policy.
Scenario 3: Web site busy.example.com also has a contract
with an advertising company called clickads.example.com to provide banner ads
on its site. The contract allows Clickads to set cookies so as to make sure
each user does not see a given ad more than three times. Clickads collects
statistics on how many users view each ad and reports them to the companies
whose products are being advertised. But these reports do not reveal
information about any individual users. As was the case in Scenario 2, Busy's
privacy policies applies to these ads hosted by Clickads, so Busy uses the
HINT
element in its policy reference file to point to a suitable
policy reference file at Clickads, indicating that Busy P3P policy applies to
such embedded content served by clickads.example.com. The companies whose
products are being advertised need not be mentioned in the Busy privacy
policy because the only data they are receiving is aggregate data.
Scenario 4: Web site busy.example.com also has a contract
with funchat.example.com to host a chat room for its users. When users enter
the chat room they are actually leaving the Busy site. However, the chat room
has the Busy logo and is actually covered by the Busy privacy policy. In this
instance Funchat is acting as an agent for Busy, but -- unlike the previous
examples -- their content is not embedded in the Busy site. Busy can use the
HINT
element in its policy reference file to point to a suitable
Funchat policy reference file, that indicates that Funchat chat room is
covered by Busy privacy policy, therefore facilitating a smoother transition
to the chat room.
Scenario 5: Web site bigsearch.example.com has a form
that allows users to type in a search query and have it performed on their
choice of search engines located on other sites. When a user clicks the
"submit" button, the search query is actually submitted directly to these
search engines -- the action URI is not on bigsearch.example.com but rather
on the search engine selected by the user. Bigsearch can declare the privacy
policies for these search engines by using the HINT
element to
point to their corresponding policy reference files. So when a user clicks
the "submit" button, their user agent can check its privacy policy before
posting any data. In order to make this search choice mechanism work,
Bigsearch might actually have a form with an action URI on its own site,
which redirects to the appropriate search engine. In this case, the user
agent should check the search engine privacy policy upon receiving the
redirect response.
Scenario 6: Web site bigsearch.example.com also has a form that allows users to type in a search query and have it simultaneously performed on ten different search engines. Bigsearch submits the queries, gets back the results from each search engine, removes the duplicates, and presents the results to the user. In this case, the user interacts only with Bigsearch. Thus, the only P3P policy involved is the one that covers the Bigsearch Web site. However, Bigsearch must disclose that it shares the users' search queries with third parties (the search Web sites), unless Bigsearch has a contract with these search engines and they act as agents to Bigsearch.
Scenario 7: Web site bigsearch.example.com also has
banner advertisements provided by a company called adnetwork.example.com.
Adnetwork uses cookies to develop profiles of users across many different Web
sites so that it can provide them with ads better suited to their interests.
Because the data about the sites that users are visiting is being used for
purposes other than just serving ads on the Bigsearch Web site, Adnetwork
cannot be considered an agent in this context. Adnetwork must create its own
P3P policy and use its own policy reference file to indicate what content it
applies to. In addition, Bigsearch may optionally use the HINT
element in its policy reference file to indicate that the Adnetwork P3P
policy reference file applies to these advertisements. Bigsearch should only
do this if Adnetwork has told it what P3P policy applies to these
advertisements and has agreed to notify Bigsearch if the policy reference
needs to be changed.
Scenario 8: Web site busy.example.com uses cookies
throughout its Web site. It discloses a cookie policy, separate from its
regular P3P policy to cover these cookies. It uses the
COOKIE-INCLUDE
element in its policy reference file to declare
the appropriate policy for these cookies. As a performance optimization, it
also makes available a compact policy by sending a P3P header that includes
this compact policy whenever it sets a cookie.
Scenario 9: Web site config.example.com provides a
service in which they optimize various kinds of Web content based on each
user's computer and Internet configuration. Users go to the Config Web site
and answer questions about their computer, monitor, and Internet connection.
Config encodes the responses and stores them in a cookie. Later, when the
user is visiting Busy -- a Web site that has contracted with Config --
whenever the browser requests content that can be optimized (certain images,
audio files, etc.), Busy will redirect the user to Config, which will read
the user's cookie, and deliver the appropriate content. In this case, Config
should declare a privacy policy that describes the kinds of data collected
and stored in its cookies, and how that data is used. It should use a
COOKIE-INCLUDE
element in its policy reference file to declare
the policy for the cookies. It will probably reference Busy's P3P policy for
the actual images or audio files delivered, as it is acting much like CDN
acts in scenario 2. Busy will probably also use HINT
elements in
its policy reference file to reference the policy for the Config-delivered
content.
P3P policies are encoded in XML with namespaces (see [XML] and [XML-Name]). A possible encoding using the RDF data model ([RDF]) is provided in [P3P-RDF].
Section 3.1 begins with an example of an English language privacy policy
and a corresponding P3P policy. 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.
The following are two examples of English-language privacy policy to be encoded as a P3P policy. Both policies are for one example company, CatalogExample, which has different policies for those browsing their site and those actually purchasing products. Example 3.1. is provided in both English and as a more formal description using P3P element and attribute names.
CatalogExample
4000 Lincoln Ave.
Birmingham, MI 48009 USA
email<EMAIL_ADDRESS>Telephone 248-EXAMPLE<PHONE_NUMBER>)
Data retention:
We purge every two weeks the browsing information that we collect.
Here is Example 3.1 in a more formal description, using the P3P element and attribute names [with the section of the spec that was used cited in brackets for easy reference]:
CatalogExample
4000 Lincoln Ave.
Birmingham, MI 48009 USA
email<EMAIL_ADDRESS>Telephone +1 248-EXAMPLE (+1<PHONE_NUMBER>)
If you choose to purchase an item we will ask you for more information
including:
Also on this page we will give you the option to choose if you would
like to receive email, telephone calls or written service from
CatalogExample or from our carefully selected marketing partners who
maintain similar privacy practices. If you would like to receive these
solicitations simply check the appropriate boxes. You can choose to
stop participating at any time simply by changing your preferences.
Changing and Updating personal information
Consumers can change all of their personal account information by going
to the preferences section of CatalogExample at
http://catalog.example.com/preferences.html. You can change your
address, telephone number, email address, password as well as your
privacy settings.
Cookies
CatalogExample uses cookies only to see if you have been an
CatalogExample customer in the past and, if so, customize services
based on your past browsing habits and purchases. We do not store any
personal data in the cookie nor do we share or sell the any of the
information with other parties or affiliates.
Data
retention
We will keep the information about you and your purchases for as long
as you remain our customer. If you do not place an order from us for
one year we will remove your information from our databases.
The following pieces of [XML] capture the information as expressed in the above two examples. 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.
XML Encoding of Example 3.1:
<POLICIES xmlns="http://www.w3.org/2002/01/P3Pv1" xmlns:p3p11="http://www.w3.org/2006/01/P3Pv11"> <POLICY name="forBrowsers" discuri="http://www.catalog.example.com/PrivacyPracticeBrowsing.html" xml:lang="en"> <ENTITY> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:business> <p3p11:orgname>CatalogExample</p3p11:orgname> <p3p11:contact-info> <p3p11:postal> <p3p11:street>4000 Lincoln Ave.</p3p11:street> <p3p11:city>Birmingham</p3p11:city> <p3p11:state>MI</p3p11:state> <p3p11:postalcode>48009</p3p11:postalcode> <p3p11:country>USA</p3p11:country> </p3p11:postal> <p3p11:online> <p3p11:email>catalog@example.co.uk</p3p11:email> </p3p11:online> <p3p11:telecom> <p3p11:telephone> <p3p11:intcode>1</p3p11:intcode> <p3p11:loccode>248</p3p11:loccode> <p3p11:number>3926753</p3p11:number> </p3p11:telephone> </p3p11:telecom> </p3p11:contact-info> </p3p11:business> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#business.name">CatalogExample</DATA> <DATA ref="#business.contact-info.postal.street">4000 Lincoln Ave.</DATA> <DATA ref="#business.contact-info.postal.city">Birmingham</DATA> <DATA ref="#business.contact-info.postal.stateprov">MI</DATA> <DATA ref="#business.contact-info.postal.postalcode">48009</DATA> <DATA ref="#business.contact-info.postal.country">USA</DATA> <DATA<EMAIL_ADDRESS><DATA ref="#business.contact-info.telecom.telephone.intcode">1</DATA> <DATA ref="#business.contact-info.telecom.telephone.loccode">248</DATA> <DATA ref="#business.contact-info.telecom.telephone.number">3926753</DATA> </DATA-GROUP> </ENTITY> <ACCESS><nonident/></ACCESS> <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" alt="PrivacySeal's logo"/> <REMEDIES> <correct/> </REMEDIES> </DISPUTES> </DISPUTES-GROUP> <STATEMENT> <PURPOSE> <admin/> <develop/> </PURPOSE> <RECIPIENT> <ours/> </RECIPIENT> <RETENTION> <stated-purpose/> </RETENTION> <!-- Note also that the site's human-readable privacy policy MUST mention that data is purged every two weeks, or provide a link to this information. --> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:dynamic> <p3p11:clickstream/> <p3p11:http/> </p3p11:dynamic> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#dynamic.clickstream"/> <DATA ref="#dynamic.http"/> </DATA-GROUP> </STATEMENT> </POLICY> </POLICIES>
XML Encoding of Example 3.2:
<POLICIES xmlns="http://www.w3.org/2002/01/P3Pv1" xmlns:p3p11="http://www.w3.org/2006/01/P3Pv11"> <POLICY name="forShoppers" discuri="http://www.catalog.example.com/Privacy/PrivacyPracticeShopping.html" opturi="http://catalog.example.com/preferences.html" xml:lang="en"> <ENTITY> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:business> <p3p11:orgname>CatalogExample</p3p11:orgname> <p3p11:contact-info> <p3p11:postal> <p3p11:street>4000 Lincoln Ave.</p3p11:street> <p3p11:city>Birmingham</p3p11:city> <p3p11:state>MI</p3p11:state> <p3p11:postalcode>48009</p3p11:postalcode> <p3p11:country>USA</p3p11:country> </p3p11:postal> <p3p11:online> <p3p11:email>catalog@example.co.uk</p3p11:email> </p3p11:online> <p3p11:telecom> <p3p11:telephone> <p3p11:intcode>1</p3p11:intcode> <p3p11:loccode>248</p3p11:loccode> <p3p11:number>3926753</p3p11:number> </p3p11:telephone> </p3p11:telecom> </p3p11:contact-info> </p3p11:business> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#business.name">CatalogExample</DATA> <DATA ref="#business.contact-info.postal.street">4000 Lincoln Ave.</DATA> <DATA ref="#business.contact-info.postal.city">Birmingham</DATA> <DATA ref="#business.contact-info.postal.stateprov">MI</DATA> <DATA ref="#business.contact-info.postal.postalcode">48009</DATA> <DATA ref="#business.contact-info.postal.country">USA</DATA> <DATA<EMAIL_ADDRESS><DATA ref="#business.contact-info.telecom.telephone.intcode">1</DATA> <DATA ref="#business.contact-info.telecom.telephone.loccode">248</DATA> <DATA ref="#business.contact-info.telecom.telephone.number">3926753</DATA> </DATA-GROUP> </ENTITY> <ACCESS><contact-and-other/></ACCESS> <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" alt="PrivacySeal's logo"/> <REMEDIES><correct/></REMEDIES> </DISPUTES> </DISPUTES-GROUP> <STATEMENT> <CONSEQUENCE> We record some information in order to serve your request and to secure and improve our Web site. </CONSEQUENCE> <PURPOSE><admin/><develop/></PURPOSE> <RECIPIENT><ours/></RECIPIENT> <RETENTION><stated-purpose/></RETENTION> <DATA-GROUP> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:dynamic> <p3p11:clickstream/> <p3p11:http> <p3p11:useragent/> </p3p11:http> </p3p11:dynamic> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA ref="#dynamic.clickstream"/> <DATA ref="#dynamic.http.useragent"/> </DATA-GROUP> </STATEMENT> <STATEMENT> <CONSEQUENCE> We use this information when you make a purchase. </CONSEQUENCE> <PURPOSE><current/></PURPOSE> <RECIPIENT><ours/></RECIPIENT> <RETENTION><stated-purpose/></RETENTION> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:user> <p3p11:name/> <p3p11:home-info> <p3p11:postal/> <p3p11:telecom> <p3p11:telephone/> </p3p11:telecom> <p3p11:online> <p3p11:email/> </p3p11:online> </p3p11:home-info> <p3p11:business-info> <p3p11:postal/> <p3p11:telecom> <p3p11:telephone/> </p3p11:telecom> </p3p11:business-info> <p3p11:login> <p3p11:id/> <p3p11:password/> </p3p11:login> </p3p11:user> <p3p11:dynamic> <p3p11:miscdata> <p3p11:category> <p3p11:purchase/> </p3p11:category> </p3p11:miscdata> </p3p11:dynamic> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#user.name"/> <DATA ref="#user.home-info.postal"/> <DATA ref="#user.home-info.telecom.telephone"/> <DATA ref="#user.business-info.postal"/> <DATA ref="#user.business-info.telecom.telephone"/> <DATA ref="#user.home-info.online.email"/> <DATA ref="#user.login.id"/> <DATA ref="#user.login.password"/> <DATA ref="#dynamic.miscdata"> <CATEGORIES> <purchase/> </CATEGORIES> </DATA> </DATA-GROUP> </STATEMENT> <STATEMENT> <CONSEQUENCE> At your request, we will send you carefully selected marketing solicitations that we think you will be interested in. </CONSEQUENCE> <PURPOSE> <contact required="opt-in"/> <individual-decision required="opt-in"/> <tailoring required="opt-in"/> </PURPOSE> <RECIPIENT><ours/><same required="opt-in"/></RECIPIENT> <RETENTION><stated-purpose/></RETENTION> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:user> <p3p11:name/> <p3p11:home-info> <p3p11:postal/> <p3p11:telecom> <p3p11:telephone/> </p3p11:telecom> <p3p11:online> <p3p11:email/> </p3p11:online> </p3p11:home-info> <p3p11:business-info> <p3p11:postal/> <p3p11:telecom> <p3p11:telephone/> </p3p11:telecom> </p3p11:business-info> </p3p11:user> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#user.name" optional="yes"/> <DATA ref="#user.home-info.postal" optional="yes"/> <DATA ref="#user.home-info.telecom.telephone" optional="yes"/> <DATA ref="#user.business-info.postal" optional="yes"/> <DATA ref="#user.business-info.telecom.telephone" optional="yes"/> <DATA ref="#user.home-info.online.email" optional="yes"/> </DATA-GROUP> </STATEMENT> <STATEMENT> <CONSEQUENCE> We allow you to set a password so that you can access your own information. </CONSEQUENCE> <PURPOSE><individual-decision required="opt-in"/></PURPOSE> <RECIPIENT><ours/></RECIPIENT> <RETENTION><stated-purpose/></RETENTION> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:user> <p3p11:login> <p3p11:id/> <p3p11:password> <CATEGORIES> <uniqueid /> </CATEGORIES> </p3p11:password> </p3p11:login> </p3p11:user> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#user.login.id"/> <DATA ref="#user.login.password"> <CATEGORIES> <uniqueid/> </CATEGORIES> </DATA> </DATA-GROUP> </STATEMENT> <STATEMENT> <CONSEQUENCE> At your request, we will tailor our site and highlight products related to your interests. </CONSEQUENCE> <PURPOSE> <pseudo-decision required="opt-in"/> <tailoring required="opt-in"/> </PURPOSE> <RECIPIENT> <ours/> </RECIPIENT> <RETENTION> <stated-purpose/> </RETENTION> <DATA-GROUP> <EXTENSION> <p3p11:data-group> <p3p11:datatype optional="yes"> <p3p11:user> <p3p11:bdate> <p3p11:ymd> <p3p11:year/> </p3p11:ymd> </p3p11:bdate> <p3p11:gender> </p3p11:gender> </p3p11:user> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA ref="#user.bdate.ymd.year" optional="yes"/> <DATA ref="#user.gender" optional="yes"/> </DATA-GROUP> </STATEMENT> <STATEMENT> <CONSEQUENCE> We tailor our site based on your past visits. </CONSEQUENCE> <PURPOSE> <tailoring/> <develop/> </PURPOSE> <RECIPIENT> <ours/> </RECIPIENT> <RETENTION> <stated-purpose/> </RETENTION> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:dynamic> <p3p11:cookies> <CATEGORIES> <state /> </CATEGORIES> <p3p11:/cookies> <p3p11:miscdata> <CATEGORIES> <preference /> </CATEGORIES> </p3p11:miscdata> </p3p11:dynamic> </p3p11:datatype> </p3p11:data-group> </EXTENSION> <DATA-GROUP> <DATA ref="#dynamic.cookies"> <CATEGORIES> <state/> </CATEGORIES> </DATA> <DATA ref="#dynamic.miscdata"> <CATEGORIES> <preference/> </CATEGORIES> </DATA> </DATA-GROUP> </STATEMENT> </POLICY> </POLICIES>
This section defines the syntax and semantics of P3P policies. All policies MUST be encoded using [UTF-8].
In cases where the P3P vocabulary is not precise enough to describe a Web
site's practices, sites should use the vocabulary terms that most closely
match their practices and provide further explanation in the
CONSEQUENCE
field and/or their human-readable policy. However,
policies MUST NOT make false or misleading statements.
Policies have to be placed inside a POLICIES
element.
POLICIES
elementThe POLICIES
element gathers one or more P3P policies
together in a single file. This is provided as a performance optimization:
many policies can be collected with a single request, improving network
traffic and caching.
A POLICIES
element is the root element of policy files.
Further, the POLICIES
element can be put within the policy
reference file, inside the META
element:: in this case, user
agents need only fetch a single file, containing both the policy reference
file and the policies.
The POLICIES
element can optionally contain an
xml:lang
attribute (see section 2.4.2),
an EXPIRY
element, indicating
the expiration of the included policies, and an embedded data schema using
the DATASCHEMA
element (see Section 5).
Since policies are included in a POLICIES
element, each MUST
have a name
attribute which is unique in the file. This allows
policy references (in POLICY-REF
elements) to link to that
policy.
Example 3.3:
The file in http://www.example.com/Shop/policies.xml
could
have the following content:
<POLICIES xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY name="policy1" discuri="http://www.example.com/disc1"> .... </POLICY> <POLICY name="policy2" discuri="http://www.example.com/disc2"> .... </POLICY> <POLICY name="policy3" discuri="http://www.example.com/disc3"> .... </POLICY> </POLICIES>
The files in http://www.example.com/Shop/CDs/*
could then be
associated to the second policy ("policy2
") using the following
policy reference file in http://www.example.com/w3c/p3p.xml
:
<META xmlns="http://www.w3.org/2002/01/P3Pv1"> <POLICY-REFERENCES> <POLICY-REF about="/Shop/policies#policy2"> <INCLUDE>/Shops/CDs/*</INCLUDE> </POLICY-REF> </POLICY-REFERENCES> </META>
| [20] | policies |
= |
`<POLICIES xmlns="http://www.w3.org/2002/01/P3Pv1"` [xml-lang] `>` [expiry] [dataschema] *policy "</POLICIES>" |
POLICY
elementThe 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 and one or more STATEMENT
elements.It SHOULD
contain a DISPUTES-GROUP
element. It may contain a P3P data schema and one or more extensions.
<POLICY>
name
(mandatory
attribute)discuri
(mandatory attribute)opturi
purpose
with required
attribute set to opt-in
or opt-out
. Note that
the opt-in or opt-out procedures are determined by each site and may
not necessarily include a central mechanism for the entire site or an
automated online mechanism.xml:lang
| [21] | policy |
= |
`<POLICY name=` quotedstring ` discuri=` quoted-URI [` opturi=` quoted-URI] [xml-lang] `>` *extension [test] entity access [disputes-group] 1*statement-block *extension `</POLICY>` |
| [22] | quoted-URI |
= |
`"` URI `"` |
| Here, URI is defined as per RFC 3986 [URI]. |
STATEMENT-GROUP-DEF
element
(EXTENSION)The STATEMENT-GROUP-DEF
extension is used to define an
identifier and optionally properties that can be applied to a group of
STATEMENT
elements using the STATEMENT-GROUP
extension. P3P user agents
that understand these two extensions MAY take this information into account
when displaying P3P policy information for users. For example, statements
that belong to the same group might be displayed together under a single
heading.
<STATEMENT-GROUP-DEF>
STATEMENT
element that defines an
identifier and optionally properties that can be applied to a group of
STATEMENT
elementsid
short-description
consent
opt-in
indicates that a user can simultaneously opt-in. A
value of opt-out
indicates that a user can simultaneously
opt-out. A value of always
indicates that no opt-in or
opt-out options are available. A value of mixed
indicates
that opt-in or opt-out may be available for some or all of the data
uses and recipients individually, but users are not able to
simultaneously consent to or withdraw consent from all of them. If this
attribute is omitted, the default value is mixed
.| [23] | sg-def-extension |
= |
`<EXTENSION optional="yes">` *[sg-def] `</EXTENSION>` |
| [24] | sg-def |
= |
`<STATEMENT-GROUP-DEF id="` quotedstring `"` [`consent ="` (`opt-in` | `opt-out` | `always` | `mixed`) `"`] [short-description] `xmlns = "http://www.w3.org/2006/01/P3Pv11"/>` |
(Note that the optional
attribute does not need to be
explicitly included because its default value is yes
.)
Because P3P 1.0 user agents are unaware of this extension (and thus will
ignore it), all statements that belong to statement groups that have
consent
attributes with values of opt-in
,
opt-out
, MUST use the corresponding required
attribute on all PURPOSE
and RECIPIENTS
elements.
If consent="always"
the required
attribute MUST be
omitted as its default value is always
. Any user agent that
relies on this extension MUST check to make sure this requirement has been
followed. If a user agent finds an inconsistency between a
consent
attribute and a required
attribute it MUST
either ignore the extension altogether or treat the statement group as if its
consent
value was mixed
.
Note that the purpose current
and the recipient
ours
do not take a required
attribute and thus
cannot be used in statement groups with consent
values other
than required
or mixed
.
Statement groups serve two main purposes:
consent
attribute of the statement group enables a
site to define usages that can only be opted in- or out together. E.g.,
an opt-in to a frequent-flyer club implies collection of email and phone
for contact as well as clickstream data for individual analysis.Statement groups are intended primarily as hints to user agents on how to display P3P policy information to users. As currently specified, they are not intended for use in automated decision-making. For example, user agents cannot make judgments automatically about which statement groups apply to the activities of their users.
<POLICY> … <EXTENSION optional="yes"> <p3p11:STATEMENT-GROUP-DEF id="browsing" consent = "always" short-description="Browsing the site" xmlns = "http://www.w3.org/2006/01/P3Pv11" /> </EXTENSION> … </POLICY>
TEST
elementThe TEST element is used for testing purposes: the presence of
TEST
in a policy indicates that the policy is just an example,
and as such, it MUST be ignored, and not be considered as a valid P3P
policy.
| [25] | test |
= |
"<TEST/>" |
ENTITY
elementThe ENTITY
element gives a precise description of the legal
entity making the representation of the privacy practices.
<ENTITY>
The ENTITY
element contains a description of the legal entity
consisting of datatype EXTENSION elements referencing (all or some of)
the fields of the business dataset as the text values of their leaf nodes (i.e. the values are typed by the schema XML):
it MUST contain both the legal entity's name and one or more contact information
fields among postal address, telephone number, email address, URI. Note that
some laws and codes of conduct require entities to include a postal address
or other specific information in their contact information.
Example of a valid ENTITY element
Note that <DATA ref=".... elements must also be included only for backward compatibility and would normally be inserted automatically by a policy editor
<ENTITY> <EXTENSION> <p3p11:data-group> <p3p11:datatype> <p3p11:business> <p3p11:orgname>CatalogExample</p3p11:orgname> <p3p11:contact-info> <p3p11:postal> <p3p11:street>4000 Lincoln Ave.</p3p11:street> <p3p11:city>Birmingham</p3p11:city> <p3p11:state>MI</p3p11:state> <p3p11:postalcode>48009</p3p11:postalcode> <p3p11:country>USA</p3p11:country> </p3p11:postal> <p3p11:online> <p3p11:email>catalog@example.co.uk</p3p11:email> </p3p11:online> <p3p11:telecom> <p3p11:telephone> <p3p11:intcode>1</p3p11:intcode> <p3p11:loccode>248</p3p11:loccode> <p3p11:number>3926753</p3p11:number> </p3p11:telephone> </p3p11:telecom> </p3p11:contact-info> </p3p11:business> </p3p11:datatype> </p3p11:data-group> </EXTENSION> … </DATA-GROUP> </ENTITY>
Although it is permissable for a particular datatype
element to
appear more than once within a single ENTITY
element, this is
not recommended as user agents may not display multiple instances of a
datatype
element correctly. Policy writers who wish to indicate
multiple points of contact for customer service at a web site should use the
DISPUTES
element, which is designed to
have multiple instances.
| [26] | entity |
= |
"<ENTITY>" *extension entitydescription *extension "</ENTITY>" |
| [27] | entitydescription |
= |
"<DATA-GROUP>" `<DATA ref="#business.name"/>` PCDATA "</DATA>" *(`<DATA ref="#business.` string `"/>` PCDATA "</DATA>") "</DATA-GROUP>" |
Here, string is defined as a
sequence of characters (with " and & escaped) among the values
that are allowed by the business
dataset. PCDATA is defined as in [XML]. |
ACCESS
elementThe ACCESS
element indicates whether the site provides access
to various kinds of information.
<ACCESS>
<all/>
) 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 of the following
elements:
<nonident/>
<all/>
<contact-and-other/>
<ident-contact/>
<other-ident/>
<none/>
| [28] | access |
= |
"<ACCESS>" *extension access_disclosure *extension "</ACCESS>" |
| [29] | access_disclosure |
= |
"<nonident/>" | ; Identified Data is Not Used "<all/>" | ; All Identifiable Information "<contact-and-other/>" | ; Identified Contact Information and Other Identified Data "<ident-contact/>" | ; Identifiable Contact Information "<other-ident/>" | ; Other Identified Data "<none/>" ; None |
DISPUTES
elementA 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 an
entity's privacy practices. Each DISPUTES
element can optionally
contain a LONG-DESCRIPTION
element, an IMG
element,
and a REMEDIES
element. Entities with multiple dispute
resolution procedures should use a separate DISPUTES
element for
each. Since different dispute procedures have separate remedy processes, each
DISPUTES
element would need a separate
LONG-DESCRIPTION
, IMG
tag and REMEDIES
element, if they are being used.
<DISPUTES>
resolution-type
(mandatory
attribute)[service]
[independent]
[court]
[law]
service
(mandatory
attribute)verification
short-description
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>
<IMG>
src
(mandatory
attribute)width
height
alt
(mandatory attribute)| [30] | disputes-group |
= |
"<DISPUTES-GROUP>" *extension 1*dispute *extension "</DISPUTES-GROUP>" |
| [31] | dispute |
= |
"<DISPUTES" " resolution-type=" '"'("service"|"independent"|"court"|"law")'"' " service=" quoted-URI [" verification=" quotedstring] [" short-description=" quotedstring] ">" *extension [longdescription] [image] [remedies] *extension "</DISPUTES>" |
| [32] | longdescription |
= |
<LONG-DESCRIPTION> PCDATA </LONG-DESCRIPTION> |
| [33] | image |
= |
"<IMG src=" quoted-URI [" width=" `"` number `"`] [" height=" `"` number `"`] " alt=" quotedstring "/>" |
| [34] | quotedstring |
= |
`"` string `"` |
Here, string is defined as a
sequence of characters (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, including
representing that one's privacy practices are self assured, audited by a
third party, or under the jurisdiction of a regulatory authority.
REMEDIES
elementEach DISPUTES
element SHOULD contain a REMEDIES
element that specifies the possible remedies in case a policy breach
occurs.
<REMEDIES>
The REMEDIES
element must contain one or more of the
following:
<correct/>
<money/>
<law/>
| [35] | remedies |
= |
"<REMEDIES>" *extension 1*remedy *extension "</REMEDIES>" |
| [36] | remedy |
= |
"<correct/>" | "<money/>" | "<law/>" |
Statements describe data practices that are applied to particular types of data.
STATEMENT
elementThe STATEMENT
element is a container that groups together a
PURPOSE
element, a RECIPIENT
element, a
RETENTION
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>
| [37] | statement-block |
= |
"<STATEMENT>" *extension [consequence] ((purpose recipient retention 1*data-group) | (non-identifiable [purpose] [recipient] [retention] *data-group)) *extension "</STATEMENT>" |
To simplify practice declaration, service providers may aggregate any of
the disclosures (purposes, recipients, and retention) 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 postal
code to unrelated
(unrelated third parties), MAY say they
distribute your name and postal 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. Note that when aggregating
disclosures across statements that include the NON-IDENTIFIABLE
element, this element may be included in the aggregated statement only if it
would otherwise appear in every statement if the statements were written
separately.
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 Activity For Which Data Was Provided) 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.
Service providers often aggregate data they collect. Sometimes this aggregate data may be used for different purposes than the original data, shared more widely than the original data, or retained longer than the original data. For example many sites publish or disclose to their advertisers statistics such as number of visitors to their Web site, percentage of visitors who fit into various demographic groups, etc. When aggregate statistics are used or shared such that it would not be possible to derive data for individual people or households based on these statistics, no disclosures about these statistics are necessary in a P3P policy. However, services MUST disclose the fact that the original data is collected and declare any use that is made of the data before it is aggregated.
STATEMENT-GROUP
element
(EXTENSION)A statement can be associated with a statement group. Each statement can
have at most one <STATEMENT-GROUP> extension.
A STATEMENT-GROUP
can carry at most two attributes: The
id-attribute
and the name-attribute
:
The id-attribute
associates a STATEMENT
with a
certain group of STATEMENTs
to cluster them together to reflect
a certain typical usage (see STATEMENT-GROUP-DEF
for more
information
The STATEMENT-GROUP
is placed after the opening tag of the
STATEMENT
element.
The name-attribute
associates a name to a certain statement.
User agents may use this name to improve the display of the policy to the
user in a human readable format. This extension was taken up from one
implementer's authoring tool. Note that versions of this tool up through
version 1.10 used an optional GROUP-INFO extension to name each statement.
This extension provides the same function as the name attribute
in the STATEMENT-GROUP
extension. For backwards compatibility
with existing P3P 1.0 policies, user agent implementers may wish to include
support for this old extension. The old extension provided by the tool is
placed after the opening tag of a STATEMENT
element and takes
the form
<EXTENSION optional="yes"> <GROUP-INFO xmlns="http://www.software.ibm.com/P3P/editor/extension-1.0.html" name="example"/> </EXTENSION>
In this sample example