The IP Database can pass reverse DNS information back and forth to a DNS management backend to simplify maintenance of the reverse DNS records associated with the IPs being managed.
Reverse zones are created on /16 or /24 boundaries for IPv4, since simple classful delegation can't be done at other boundaries anyway.
Several shortcuts can be used when specifying a pattern for an IPv4 netblock, which will be expanded to actual DNS records by the DNS management system.
| Substitution pattern | Example expansion using 192.168.23.45 | |
| Whole-IP patterns | ||
| Dashed IP | %i | 192-168-23-45 |
| Reverse dashed IP | %r | 45-23-168-192 |
| Hex-coded IP | %h | c0a8172d |
| Decimal IP | %d | 323241453 |
| Per-octet patterns (1, 2, 3, or 4 specify the octet; d, h or 0 specify decimal, hexidecimal, or 0-padded decimal) | ||
| First octet, decimal | %1d | 192 |
| Third octet, 0-padded | %30 | 023 |
| Fourth octet, hexidecimal | %4h | 2d |
| All octets, different expansions | %1h-%2d-%30-%4h | c0-168-023-2d |