# R53\_ZONE

`R53_ZONE` lets you specify the AWS Zone ID for an entire domain ([`D()`](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/language-reference/top-level-functions/d)) or a specific [`R53_ALIAS()`](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/language-reference/domain-modifiers/service-provider-specific/amazon-route-53/r53_alias) record.

When used with [`D()`](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/language-reference/top-level-functions/d), it sets the zone id of the domain. This can be used to differentiate between split horizon domains in public and private zones. See this [example](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/service-providers/providers/route53#split-horizon) in the [Amazon Route 53 provider page](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/service-providers/providers/route53).

When used with [`R53_ALIAS()`](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/language-reference/domain-modifiers/service-provider-specific/amazon-route-53/r53_alias) it sets the required Route53 hosted zone id in a R53\_ALIAS record. See [`R53_ALIAS()`](https://docs.dnscontrol.org/~/revisions/T4Wre387kGCjR4Bh4mfN/language-reference/domain-modifiers/service-provider-specific/amazon-route-53/r53_alias) documentation for details.