z.ns.se has no CNAME records.
Question and response
Question
dig z.ns.se. NS
Answer
The response has no answer records.
Authority
se. 5156 SOA catcher-in-the-rye.nic.se. registry-default.nic.se. 1772797198 7200 1800 864000 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0