According to https://www.w3.org/TR/referrer-policy/, there is no never value for referrer-policy, and the unrecognized value will be default policy.

Browsers may support those nonstandard values for legacy compatibility but not recommended now.

none never comes from the W3C First Public Working Draft at 2014. See https://www.w3.org/TR/2014/WD-referrer-policy-20140807/#referrer-policy-delivery-meta