Every .dk domain that delegates its _acme-challenge name to b2dce71d-5168-4eaa-a1f7-994fbc5b00b4.12.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.