Every .dk domain that delegates its _acme-challenge name to ad9388a2-3609-4e8b-827c-db71c70f539b.5.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.