By default, MyDNS responds to requests for records in the in-addr.arpa
zone by referencing the ptr table. If any matching records exist,
MyDNS considers itself authoritative for that portion of the in-addr.arpa
namespace and serves the requested record(s). If the request is for a
soa record in in-addr.arpa (for example, when BIND 8 initiates
an AXFR), MyDNS fabricates a SOA record.
If you want to set up your own SOA record for an in-addr.arpa zone, you
may feel free to do so. MyDNS will honor it when soa requests are
received for those records, instead of making up its own SOA record.
If you need to do RFC 2317-style classless delegation (see see RFC 2317),
you may add a PTR value to the type column in the
ptr table. When MyDNS answers requests in IN-ADDR.ARPA zones, it
attempts to combine any data found in either the ptr or rr tables.
(See rr table.)