Selected answers from the Dumb SEO Questions Facebook & G+ community.
Michael Martinez: "noreferrer" tells the browser not to pass any information from the current window/page/session if the user clicks on that link. To the destination site, it will look like a "direct" click.
"nofollow" tells (some) search engines to drop the link from their graph - to pretend it doesn`t exist. Google says they take that only as a suggestion.
"noopener" tells the browser not to allow the destination page to do anything with the linking/opening page via Javascript.
Nathan Bradshaw: Thank you very much for the detailed response.
Ben Dadoun: Michael Martinez thanks for the reply.I thought “Noopener†means that the link open in a new browser tab and not in the same one…
Michael Martinez: Ben Dadoun https://developer.mozilla.org/.../HTML/Link_types/noopener
DEVELOPER.MOZILLA.ORGLink types: noopener - HTML: HyperText Markup Language | MDNLink types: noopener - HTML: HyperText Markup Language | MDN