ccTLD/uk/ac.ukについて、ここに記述してください。

This is for academic establishments such as universities and is managed by JANET (UK).
  https://www.ja.net/products-services/janet-connect/dns-domain-name-allocation


$ dnsq ns ac.uk nsd.nic.uk
{{{
2 ac.uk:
191 bytes, 1+0+7+0 records, response, noerror
query: 2 ac.uk
authority: ac.uk 172800 NS ns4.ja.net
authority: ac.uk 172800 NS ns2.ja.net
authority: ac.uk 172800 NS ns1.surfnet.nl
authority: ac.uk 172800 NS ws-fra1.win-ip.dfn.de
authority: ac.uk 172800 NS ns0.ja.net
authority: ac.uk 172800 NS ns3.ja.net
authority: ac.uk 172800 NS auth03.ns.uu.net
}}}