Every .dk domain that delegates its _acme-challenge name to 65f3ba8f-e7e7-4e4c-8f6b-7c1a82b1c8a3.auth.acme-dns.io. 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.