Every .dk domain that delegates its _acme-challenge name to 286d7581-99c7-4f89-b1d3-10c86ef4d8a0.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.