Every .dk domain that delegates its _acme-challenge name to 57de3ac9-03e9-43a2-b93f-8b8cb50ac92a.acmeauth.lithosting.dk. 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.