The nameserver theo.ns.cloudflare.com appears in the delegation of 280 .dk domains in our dataset — 0.02% of every scanned .dk domain. The full list is below — here is how those domains look under the hood.

On the DNSSEC side, 54 (19.3%) validate as secure — below the zone-wide average of 62.7%, while 216 (77.1%) are unsigned, and 8 (2.9%) currently fail validation outright (bogus) — a further 2 come back indeterminate.

One thing worth flagging: 9 of these domains (3.2%) look like lame delegations — the .dk registry still points them here, but this nameserver doesn't answer authoritatively for the zone, which usually means the hosting was cancelled and the delegation was left dangling.