Every .dk domain that delegates its _acme-challenge name to ac.3d0df0d1aaab80adb419ee349307c6a1.loopnet.dk.validate-akdv.net. 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.