Every .dk domain that delegates its _acme-challenge name to 4adca5a9-8ce1-43ef-928e-19a7b8b2edd0.7.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.