Every .dk domain that delegates its _acme-challenge name to 32f691d7-6d5d-43f2-a8de-44388f484c39.auth.acme-challenge.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.