It is a successor to the WHOIS protocol, used to look up relevant registration data from such Internet resources as domain names, IP addresses, and autonomous system numbers.
[2] RDAP designers, many of whom are members of number or name registries, strove to keep the protocol as simple as possible, since complexity was considered one of the reasons why previous attempts, such as CRISP, failed.
RDAP is based on RESTful web services, so that error codes, user identification, authentication, and access control can be delivered through HTTP.
Those registries started empty and will be gradually populated as registrants of domains and address spaces provide RDAP server information to IANA.
[9] Thanks to the standard document format, tasks such as, for example, getting the abuse team address of a given IP number can be accomplished in a fully automated manner.
[12] To keep RDAP information accurate, registrars have to send a yearly Whois Data Reminder Policy (WDRP) notice to the registrant contact.