This is inspired by a comment from @briansmith.
This will give more control for ads. https://lists.w3.org/Archives/Public/public-webappsec/2015Feb/0230.html
This delivery mechanism is meant to subsume the rel="noreferrer" link type defined in the HTML5 spec: https://html.spec.whatwg.org/multipage/semantics.html#link-type-noreferrer This would allow for the following use case: - I don't want any referrers to be sent (i.e. global policy of "no-referrer" delivered via <meta> or CSP) - except for these two links that should reveal the origin of the referring page (i.e. local policy of "origin" on the two <a> elements)
…header. Hixie noted in  that HTML's Fetch algorithm drops the 'referer' header when making requests from unique origins. Firefox honors this requirement, Chrome currently doesn't. Filed https://crbug.com/397011 to cover it. : http://lists.w3.org/Archives/Public/public-webappsec/2014Jul/0101.html
Hixie noted that we do a poor job specifying where we get the URL we're eventually going to use to generate the referrer. This patch attempts to explain the logic in less hand-wavey ways that don't just pull URLs out of thin air. : http://lists.w3.org/Archives/Public/public-webappsec/2014Jul/0101.html