Every .dk domain that delegates its _acme-challenge name to f8b00bc4-c522-4553-8a1e-404f828e3ddc.19.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.