Every .dk domain that delegates its _acme-challenge name to _acme-challenge.cb7ec1628e88ba3a6a03897816a7f1b484ce9f982d585d84.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.