Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '72.18.77.0'
+094
ERRNo PTR record availible DNS server 'x.arin.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.77.18.72.in-addr.arpa'.