Reverse zone

[Johnny Fribert Lauridsen]

If I owned 172.0.0.0, I would probably call my reverse zone 172.in-addr.arpa.
If I owned 172.25.0.0, I would probably call my reverse zone 172.25.in-addr.arpa.
If I now have, for example:
host 172.25.3.4, mask 255.255.240.0
and
host 172.20.0.101, mask 255.255.240.0
what would be the proper ???.in-addr.arpa names of these reverse zones for these hosts.
/fribert