Every .dk domain that delegates its _acme-challenge name to 9b7b0ef9-fda2-4a59-b70d-b8a4a3888902.acme.aau.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.