Every .dk domain that delegates its _acme-challenge name to 8d7b71ce-8d0f-4b3c-90bb-fe71c14577f8.0.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.