graalvm/elide.runtime.intrinsics.js/FetchRequest/referrer

referrer

open val referrer: String?

Request: Referrer.

Indicates the referrer value for an outgoing request in a browser. Typically not used server-side.

From MDN: "The referrer read-only property of the Request interface is set by the user agent to be the referrer of the Request. (e.g., client, no-referrer, or a URL.)"

See also: MDN, Request.referrer.