Support for the HTML referrerpolicy attribute on elements: <a>, <area>, <img>, <iframe> (and possibly others) allowing authors to set a Referrer-Policy for a single request associated with the HTML element referencing a sub-resource. More details are disclosed in the spec.
Docs: https://goo.gl/aMFGRY https://developer.mozilla.org/en-US/docs/Web/HTML/Element/a https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers https://developer.mozilla.org/en-US/docs/Web/HTTP/Content_negotiation https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta