Every .dk domain whose web server address has the reverse-DNS (PTR) name b.f.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.1.1.0.2.1.0.1.0.0.2.6.2.ip6.arpa.eu.iphmx.com, which usually identifies one physical or virtual hosting server. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.