Obsolete This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The obsolete Cookie2 HTTP request header used to advise the server that the user agent understands "new-style" cookies, but nowadays user agents will use the Cookie header instead, not this one.
Historic specification of HTTP State Management Mechanism, obsoleted by RFC 6265
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.