Why am I seeing rel=”noopener noreferrer” in my WordPress links?

As of WordPress 4.7.4, when you include a link in a post that opens in a new tab, WordPress will automatically modify the link to include the following rel attribute: <a href="https://www.google.com" target="_blank" rel="noopener noreferrer">Google</a> With the rel attribute set this way, the site you browse to will not receive the Referrer in the header of your request. That means any tracking they are doing, like through Google Analytics, will not display your website as being a referring site. You may depend on external sites seeing your domain in their analytics to prove value or popularity or something, so you may not want this new functionality in 4.7.4.