co.uk has no TXT records.
Question and response
Question
dig co.uk. TXT
Answer
The response has no answer records.
Authority
co.uk. 10800 SOA dns1.nic.uk. hostmaster.nominet.org.uk. 1772956199 900 300 2419200 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0