Every .dk domain that delegates its _acme-challenge name to b103f584-3de0-4a92-b43e-e97feb41209a.trustzonevalidation.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.