DNS NAPTR record explained.
The DNS NAPTR record is a Name Authority Pointer record that helps with mapping servers to the users’ addresses in the Session Initiation Protocol or SIP for short. The NAPTR records, together with a different type of DNS record named SRV (service) record, let the chaining of various records set complex rewrite rules. As a result, they produce new domain labels or Uniform Resource Identifiers (URIs).
Based on the flag of the recently designed URI or domain label, it is possible to be applied in the following query for a DNS NAPTR record. It could also be straight as an output of the complete process for URI mapping.
When the DNS NAPTR record is present, it lets lookup at services for various different resource names such as URIs. These, in other cases, are not usual pieces of a domain name syntax.