The presence of this attribute instructs the client to not send the HTTP header "Referer" [1] when making a request to the target URL.
[0] https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes... [1] https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Re...
<a href="http://www.jwz.org/blog/2011/10/eff-declares-premature-victo..." rel="noreferrer">Jwz: Google's pseudonym support "obvious bullshit"</a>
Might be that the method is different on a specific browser, but most likely you are looking in the wrong place.
I can see no `rel` attribute on other submitted links.
Are you perhaps using some privacy-enhancing browser extension which adds the `rel=noopener` attribute to every link?