A resource record in a zone file that contains a record associating an IP address with a host name in the in-addr.arpa domain. Pointer (PTR) records are used for reverse name lookups and provide host name to IP address mappings. Here is an example of a PTR record:
220.127.116.11.in-addr.arpa IN PTR server9.microsoft.com.
In this PTR record, the IP address 18.104.22.168 is mapped to the host Server9 within the microsoft.com domain. Note that the IP address of the host appears in the reverse order in the in-addr.arpa domain.
With the DNS service installed on Microsoft Windows NT or Windows 2000, you can automatically create an associated PTR record for each host when you create its host record.