Every .dk domain that delegates its _acme-challenge name to 364ddcb4-c3a7-4ee0-a5d5-7b9267253a6e.auth.acme-dns.io. 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.