Every .dk domain that delegates its _acme-challenge name to 3204e210f8ad27932bbd0fa4cf4967d9_knoxydk.v1.seravocerts.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.