Mention how to immediately remove cookies (#41354)

* Mention how to immediately remove cookies

* Update files/en-us/web/http/guides/cookies/index.md

Co-authored-by: Hamish Willee <[email protected]>

* Update files/en-us/web/http/guides/cookies/index.md

---------

Co-authored-by: Hamish Willee <[email protected]>

Author: Josh-Cena

files/en-us/web/http/guides/cookies/index.md

@@ -92,6 +92,19 @@ You can specify an expiration date or time period after which the cookie should
   > [!NOTE]
   > If your site authenticates users, it should regenerate and resend session cookies, even ones that already exist, whenever a user authenticates. This approach helps prevent [session fixation](https://owasp.org/www-community/attacks/Session_fixation) attacks, where a third-party can reuse a user's session.
 
+To immediately remove a cookie, set the cookie again with the same name, path, and domain (if specified), and set its `Expires` attribute to a date in the past or its `Max-Age` attribute to `0` or negative. This instructs the browser to delete the cookie right away. For example:
+
+```http
+Set-Cookie: id=a3fWa; Max-Age=0
+```
+
+You can also clear all cookies associated with a registrable domain using the {{httpheader("Clear-Site-Data")}} response header.
+For example, the following header sent from `https://foo.example.com/` would clear all cookies sent by `example.com` and all of its subdomains, such as `all.bar.example.com`.
+
+```http
+Clear-Site-Data: "cookies"
+```
+
 There are some techniques designed to recreate cookies after they're deleted. These are known as "zombie" cookies. These techniques violate the principles of user [privacy](#privacy_and_tracking) and control, may violate [data privacy regulations](#cookie-related_regulations), and could expose a website using them to legal liability.
 
 ### Updating cookie values