Every .dk domain that delegates its _acme-challenge name to c6ea0f9b-8a9e-461b-a7fa-cfd8c4463a33.0.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.