Every .dk domain that delegates its _acme-challenge name to 7c56e2c9-0260-4660-8cd4-f4e8ccc2d4d8.validation.litium.cloud. 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.