DNS: Blocking A/ipv4 Entry?

I found this almost 9 year old topic where they recommend setting A entry to 127.0.0.1 instead of 0.0.0.0 (cause ROS wont allow that. Pretty wild i think)
http://forum.mikrotik.com/t/feature-dns-allow-0-0-0-0-as-address-for-dns-records/102723/1

Which does seem to work.