Every .dk domain that delegates its _acme-challenge name to 24980934-91f4-4d05-a631-bf2a1f177be1.c-8a1f.tx.auth.certifytheweb.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.