Every .dk domain that delegates its _acme-challenge name to 33e3aa36-74cb-4964-91d1-eee0e1a5b9bd.18.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.