Every .dk domain that delegates its _acme-challenge name to b862520f-6407-42f1-a39f-63116b0ecc0d.5.authorize.certificatemanager.goog. 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.