generated: '2026-09-07'
method: searched
source: >-
  wsdl/css-validator.wsdl, https://jigsaw.w3.org/css-validator/api.html,
  https://www.w3.org/policies/patent-policy/ and https://www.w3.org/policies/process/
summary: >-
  Two kinds of conformance are recorded here and they should not be confused. The first is
  what the CSS Validation Service's own contract conforms to — SOAP 1.2, WSDL 2.0, XML Schema
  and, in its result vocabulary, EARL. The second is the governance regime CSS itself is
  published under: the W3C Process and the W3C Royalty-Free Patent Policy. Every entry cites
  the exact document location the claim is read from.
conformance:
  - id: soap12
    name: SOAP 1.2
    conforms: true
    evidence: >-
      wsdl/css-validator.wsdl declares wsoap:protocol="http://www.w3.org/2003/05/soap/bindings/HTTP"
      and the response envelope namespace http://www.w3.org/2003/05/soap-envelope; the service
      switches to this interface on output=soap12.
    url: https://www.w3.org/2005/09/css-validator.wsdl
  - id: wsdl20
    name: WSDL 2.0
    conforms: true
    evidence: >-
      The description element is in the WSDL 2.0 namespace http://www.w3.org/ns/wsdl and uses
      WSDL 2.0 constructs (interface, message exchange pattern in-out, wsdlx:safe, endpoint).
      api.html calls it "A WSDL 2 description file".
    url: https://www.w3.org/2005/09/css-validator.wsdl
  - id: xml-schema
    name: XML Schema 1.0
    conforms: true
    evidence: The WSDL types section embeds an xs:schema defining every request and response type.
    url: https://www.w3.org/2005/09/css-validator.wsdl
  - id: safe-idempotent-http
    name: HTTP safe method semantics
    conforms: true
    evidence: >-
      Both WSDL operations carry wsdlx:safe="true" and the documented programmatic interface is
      an HTTP GET, so the contract itself asserts the operations have no side effects.
    url: https://jigsaw.w3.org/css-validator/api.html
  - id: rfc9457
    name: RFC 9457 Problem Details
    conforms: false
    evidence: >-
      Faults are SOAP faults and validation findings are 200 result payloads. No
      application/problem+json anywhere. See errors/css-problem-types.yml.
  - id: oauth2
    name: OAuth 2.0
    conforms: false
    evidence: >-
      No authorization surface exists. /.well-known/oauth-authorization-server returned 404 on
      all three hosts (well-known/css-well-known.yml).
  - id: oidc
    name: OpenID Connect
    conforms: false
    evidence: /.well-known/openid-configuration returned 404 on all three hosts.
  - id: pagination
    name: Result pagination
    conforms: false
    evidence: A validation response returns the complete error and warning lists; no paging exists.
  - id: idempotency-key
    name: Idempotency-Key replay protection
    conforms: false
    evidence: >-
      Not applicable rather than missing — the service is read-only, so there is nothing to
      replay-protect. conventions/css-conventions.yml records coverage na.
domain_standards:
  - id: earl
    name: EARL — Evaluation and Report Language
    conforms: true
    partial: true
    market: automated conformance evaluation and accessibility reporting
    evidence: >-
      The API documentation defines the response vocabulary in EARL terms explicitly: "uri —
      the address of the document validated. In EARL terms, this is the TestSubject" and
      "checkedby — Location of the service which provided the validation result. In EARL
      terms, this is the Assertor." The response therefore carries an EARL assertion structure
      (TestSubject, Assertor, outcome via validity) inside the SOAP payload.
    location: https://jigsaw.w3.org/css-validator/api.html#soap12response
    caveat: >-
      The service maps its fields onto EARL roles but does not serialize EARL RDF, and no
      output=earl format is offered. Recorded as a partial, documented alignment — not as an
      EARL-conformant report generator.
  - id: w3c-patent-policy-rf
    name: W3C Royalty-Free Patent Policy
    conforms: true
    market: web standards
    evidence: >-
      CSS is developed by a W3C Working Group and every CSS Recommendation is published under
      the W3C Patent Policy, which commits participants to royalty-free licensing of essential
      claims. This is what makes CSS free to implement, and it is the substance behind the
      empty pricing model in plans/css-plans-pricing.yml.
    location: https://www.w3.org/policies/patent-policy/
  - id: w3c-process
    name: W3C Process Document
    conforms: true
    market: web standards
    evidence: >-
      CSS modules advance through the W3C Process maturity ladder and can only be superseded,
      obsoleted or rescinded through the procedures it defines. See lifecycle/css-lifecycle.yml.
    location: https://www.w3.org/policies/process/
test_suites:
  - name: CSS Working Group test suite (Web Platform Tests)
    url: https://github.com/web-platform-tests/wpt/tree/master/css
    status: 200
    note: >-
      The CSSWG's conformance tests were folded into web-platform-tests. test.csswg.org now
      serves the CSS Working Group wiki rather than a standalone suite.
  - name: Implementation results dashboard
    url: https://wpt.fyi/results/css
    status: 200
certifications:
  published: []
  note: >-
    No SOC 2, ISO 27001, PCI, HIPAA or FedRAMP program is published for w3.org or for the
    validation service. probe-security-programs.py found no trust center and no vulnerability
    disclosure program on 2026-09-07. No Compliance pointer is emitted.