Sponsor: Epsilon
Background:
Google recently published an update regarding the UK CMA-aligned Chrome cookie deprecation testing labels announced in May. Chrome intends to label 9.5% percent of Chrome Stable browsers globally. A browser instance, if labeled, is either Mode A (8.5%, opt-in testing beginning Q4 2023) or Mode B (1%, forced cookie deprecation beginning Q1 2024). Two means are offered to access the label. One can read a request header after setting a special partitioned (CHIPS) cookie or client-side via a new Navigator script API promise.
Proposal:
Entities are encouraged to access the label and to share the value unmodified with partners via the following Device extension.
| Attribute | Type | Description |
cdep |
string | the label as received from Chrome or an upstream partner |
Notes
No requirement to communicate label provenance, header versus API access.
Privacy Sandbox enrollment is not required to access the labels.
If you have opinions or feedback about the test group labeling plans, the Chrome team has encouraged interested parties to weigh in on the Privacy Sandbox Developer Support “chrome-testing” issues. Link below.
References
Chrome-facilitated testing (Chrome Developer Relations)
https://developer.chrome.com/docs/privacy-sandbox/chrome-testing/
Privacy Sandbox Developer Support “chrome-testing” issues, Github
https://github.com/GoogleChromeLabs/privacy-sandbox-dev-support/labels/chrome-testing
Chrome implementation Monorail issues
Sec-Cookie-Deprecation header access
https://bugs.chromium.org/p/chromium/issues/detail?id=1479071
Implement JS API for navigator.cookieDeprecationLabel.getValue()
https://bugs.chromium.org/p/chromium/issues/detail?id=1479119
Chromium Dash Schedule (Chrome milestone releases)
https://chromiumdash.appspot.com/schedule
UK Competition and Markets Authority (CMA) Test Guidelines
https://www.gov.uk/cma-cases/investigation-into-googles-privacy-sandbox-browser-changes#industry-testing
Privacy Sandbox enrollment and attestations model, GitHub
https://github.com/privacysandbox/attestation/blob/main/README.md
PSA: Third-party cookie deprecation for 1% of Chrome Stable starting Q1 2024 (blink-dev)
https://groups.google.com/a/chromium.org/g/blink-dev/c/GJl_aMO6Qt4/m/gFEMFo8FAgAJ
Intent to Prototype: Third-Party Cookie Phaseout (blink-dev)
https://groups.google.com/a/chromium.org/g/blink-dev/c/8mlWTOcEzcA/m/NZJSW0weAQAJ
Deprecate Third-Party Cookies (Chrome feature card)
https://chromestatus.com/feature/5133113939722240