Every .dk domain that delegates its _acme-challenge name to 851d98d5-eaf1-4a22-8805-23b144f03a69.17.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.