// Prefs allowing granular control of referers
// 0=don't send any, 1=send only on clicks, 2=send on image requests as well
pref("network.http.sendRefererHeader",      2);
// Set the default Referrer Policy to be used unless overriden by the site
// 0=no-referrer, 1=same-origin, 2=strict-origin-when-cross-origin,
// 3=no-referrer-when-downgrade
pref("network.http.referer.userControlPolicy", 3);
// false=real referer, true=spoof referer (use target URI as referer)
pref("network.http.referer.spoofSource", false);
// false=allow onion referer, true=hide onion referer (use target URI as referer)
pref("network.http.referer.hideOnionSource", false);
// 0=full URI, 1=scheme+host+port+path, 2=scheme+host+port
pref("network.http.referer.trimmingPolicy", 0);
// 0=full URI, 1=scheme+host+port+path, 2=scheme+host+port
pref("network.http.referer.XOriginTrimmingPolicy", 0);
// 0=always send, 1=send iff base domains match, 2=send iff hosts match
pref("network.http.referer.XOriginPolicy", 0);

// Controls whether referrer attributes in <a>, <img>, <area>, <iframe>, and <link> are honoured
pref("network.http.enablePerElementReferrer", true);