An attacker with access to our Web server could thus retrieve the information from the HTTP referrer header, maybe something like this (yes, the header name is actually misspelled in the HTTP ...

Browsers send HTTP Referrer headers to websites to indicate which location has 'referred' a user to a website server. Full URLs of referring documents are often sent in the HTTP Referrer header ...

Referrer Policy isn’t just for removing the referral value; it’s for giving you control of the value. One of the things often missed when moving from HTTP to HTTPS is setting a referrer policy.

Mozilla has announced that it will introduce a more privacy-focused Referrer Policy to protect the privacy of Firefox users starting with the web browser's next version.

John ☆.o (≧ ≦)o.☆ (@JohnMu) September 1, 2017 A Noreferrer specifies that the browser should not send a HTTP referrer header if the user follows the hyperlink.