Every .dk domain that delegates its _acme-challenge name to 46905ff0-c6b7-4fca-9aa4-a60fc129c6aa.19.authorize.certificatemanager.goog. Such CNAMEs hand DNS-01 certificate validation to a shared service, so this list shows who issues TLS certificates through it. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.