Every .dk domain that delegates its _acme-challenge name to 90e8406b3cac4671b99b31d7c83b6d17.unbouncepages.com. 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.