https://bugs.webkit.org/show_bug.cgi?id=207090
207090 – Import WPT tests to verify pings do not send a referrer header
do notreferrer headerimportwpttests
https://verifiedapp.io/blog/referrer-policy
Referrer-Policy header explained
Jun 5, 2026 - The Referrer-Policy header controls how much of your URL the browser sends to other sites. Here is what it leaks, the safe default, and how to set it.
referrer policyheaderexplained