Every .dk domain that delegates its _acme-challenge name to f3d23a8a-5760-431c-b520-99db6724bbd1.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.