| `IP_V4` | Enable IPv4 addresses for a provider, if neither `$IP_V4` nor `$IP_V6` are set then `$IP_V4` is enabled by default |
| `IP_V6` | Enable IPv6 addresses for provider |
| `WHITELIST` | Comma or space delimited list of domains to whitelist |
| `BLACKLIST` | Comma or space delimited list of domains to blacklist |
| `MIN_TTL` | [Override minimum TTL for entries](https://00f.net/2019/11/03/stop-using-low-dns-ttls/"Stop using ridiculously low DNS TTLs"). This technically violates DNS standards, use with care. |
| `IP_V4` | Enable IPv4 addresses for a provider, if neither `$IP_V4` nor `$IP_V6` are set then `$IP_V4` is enabled by default |
| `IP_V6` | Enable IPv6 addresses for provider |
| `WHITELIST` | Comma or space delimited list of domains to whitelist |
| `BLACKLIST` | Comma or space delimited list of domains to blacklist |
| `MIN_TTL` | [Override minimum TTL for entries](https://00f.net/2019/11/03/stop-using-low-dns-ttls/"Stop using ridiculously low DNS TTLs"). This technically violates DNS standards, use with care. |