Every .dk domain that delegates its _acme-challenge name to _acme-challenge.9ac01310829aae848a5b299bb9e38ac9fdd3e0d949697c77.upcloudlb.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.