This is a feature request to bring back the ability to hide referrer info linked to external sites by adding the Custom HTML to end of the HEAD. Following the KB How do I hide referrer info to linked external sites 

<meta name="referrer" content="no-referrer"/>

This was achievable in Confluence version prior to 7.16. After version 7.16 this no longer works especially for browsers like Firefox and Safari.
We would like to understand what has changed in version 7.16 and above that this setting no longer works.

Adding referrerPolicy: "no-referrer" now resultes in 403’s.