u.42.pl has no CNAME records.
Question and response
Question
dig u.42.pl. NS
Answer
The response has no answer records.
Authority
42.pl. 8948 SOA fns1.42.pl. freedns-admin+100854.42.pl. 2100106770 86400 10800 3628800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0