Update 2007-11-20: In November 2007, W3C announced the publication of Web Services Policy 1.5 - Primer and Web Services Policy 1.5 - Guidelines for Policy Assertion Authors as key deliverables supporting the W3C Recommendations Web Services Policy 1.5 - Framework and Web Services Policy 1.5 - Attachment. WS-Policy defines a general policy framework for expressing Web service capabilities and requirements, including a policy data model, processing model (for combining/comparing Web service capabilities), and XML Information Set representation for the policy data model.

Update 2006-03-23: In March 2006, revised versions of Web Services Policy Framework (WS-Policy) and Web Services Policy Attachment (WS-PolicyAttachment) were released.

Update 2004-09-07: See "Sonic Software and VeriSign Join as Authors on Revised WS-Policy Specifications."

[June 04, 2003] The three WS-Policy specifications have been updated to version 1.1, superseding the specifications published in December 2002. The Web Services Policy is "an initiative of the industry leaders BEA Systems, IBM, Microsoft, and SAP AG to drive and ensure interoperability for the description and communication of Web service policies. By using the XML, SOAP, and WSDL extensibility models, these WS* specifications are designed to be composed with each other to provide a rich Web services environment. The three WS-Policy specifications do not of themselves "provide a negotiation solution for Web services, [but constitute] building blocks that may be used in conjunction with other Web service and application-specific protocols to accommodate a wide variety of policy exchange models. The Web Services Policy specifications fit into the core Web service architecture since they are built on top of XML, XML Schema, WSDL, and UDDI." The new May 28, 2003 version 1.1 WS-Policy documents include Web Services Policy Framework (WS-Policy), Web Services Policy Assertions Language (WS-PolicyAssertions), and Web Services Policy Attachment (WS-PolicyAttachment). An overview communicated by Claus von Riegen (SAP AG) summarizes the V1.1 changes. The Web Service Policy 1.1 authors report their intent "to submit the specifications to a standards organization in the near future."

General WS-Policy version 1.1 changes: As for terminology, "the terms 'policy', 'policy expression', and 'policy assertion' and their usage have been aligned. The term 'policy statement' has been replaced by 'set of policy assertions'. Most of the examples have been updated with concrete policy assertions that are specified in WS-SecurityPolicy." [summary from Claus von Riegen]

Bibliographic Information and Major Changes

• WS-Policy. Web Services Policy Framework (WS-Policy). Version 1.1. 28-May-2003. By: Don Box (Microsoft), Francisco Curbera (IBM), Maryann Hondo (Editor, IBM), Chris Kaler (Editor, Microsoft), Dave Langworthy (Microsoft), Anthony Nadalin (IBM), Nataraj Nagaratnam (IBM), Mark Nottingham (BEA), Claus von Riegen (SAP), and John Shewchuk (Microsoft). 19 pages.

  "The Web Services Policy Framework (WS-Policy) provides a general purpose model and corresponding syntax to describe and communicate the policies of a Web Service. WS-Policy defines a base set of constructs that can be used and extended by other Web Services specifications to describe a broad range of service requirements, preferences, and capabilities."

  WS-Policy V1.1 changes [as summarized by Claus von Riegen]

  • Policy assertion content: "Policy operators (section 3.2.2) and policy references (section 4) are not allowed within policy assertions."
  • Removed inconsistent 'wsp:Priority': Replaced inconsistent 'wsp:Priority' with 'wsp:Preference' in policy operator example (section 3.3).
  • Consistency in policy hierarchy: Child elements must not contradict with parent elements in a policy expression (section 3.3).

• WS-PolicyAssertions. Web Services Policy Assertions Language (WS-PolicyAssertions). Version 1.1. 28-May-2003. By: Don Box (Microsoft), Maryann Hondo (IBM), Chris Kaler (Microsoft), Hiroshi Maruyama (IBM Anthony Nadalin (Editor, IBM), Nataraj Nagaratnam (IBM), Paul Patrick (BEA), Claus von Riegen (SAP), and John Shewchuk (Microsoft). 11 pages.

  The Web Services Policy Assertions Language document "specifies a set of common message policy assertions that can be specified within a policy."

• WS-PolicyAttachment. Web Services Policy Attachment (WS-PolicyAttachment). Version 1.1. 28-May-2003. By: Don Box (Microsoft), Francisco Curbera (IBM), Maryann Hondo (Editor, IBM), Chris Kaler (Editor, Microsoft), Hiroshi Maruyama (IBM), Anthony Nadalin (IBM), David Orchard (BEA), Claus von Riegen (SAP), and John Shewchuk (Microsoft). 22 pages.

  The Web Services Policy Attachment document "specifies three specific attachment mechanisms for using policy expressions with existing XML Web service technologies. Specifically, we define how to associate policy expressions with WSDL type definitions and UDDI entities. We also define how to associate implementation-specific policy with all or part of a WSDL portType when exposed from a specific implementation."

  WS-PolicyAttachment changes [as summarized by Claus von Riegen]

  • Updated deployed endpoint reference mechanism: The EndpointReference element specified in WS-Addressing is used as a domain expression for attaching policy expressions to a deployed WSDL endpoint (sections 3.2 and 4.6).
  • Attaching policy to WSDL bindings: Added a section that defines the effective policy for wsdl:binding and its part elements.
  • Generalized policy attachment to UDDI: Policy expressions can be attached [a] to any core UDDI entity and [b] in both UDDI Version 2 and 3 (section 5).
  • Remote and local policy references in UDDI: Policy expressions are referenced either remotely (via the policy expression's URI) or locally (via the tModelKey of the tModel that represents the policy expression).