$ORIGIN test.com.
$TTL 1234
@ IN SOA dns.example.com. dns2.example.com. (100 300 100 6000 600)
test.com. IN 600 A 1.2.3.4
test.com. HS 600 A 1.2.3.4
sub.test.com. 600 IN A 4.3.2.1
@ IN 600 AAAA 2001:db8::1 ; This is a comment

test.com. IN TXT pkb-client
test.com. 600 IN MX 10 mail.test.com.