RDAP (Registration Data Access Protocol) is a relatively new protocol (2015) that was introduced to standardize and then supercede Whois domain lookups. RDAP
allows for secure access to certain registration data and is returned in a different format to Whois data.
RDAP is not available through every gTLD registry. For example the .com.au registry, Afilias, has not confirmed
when registration information will be available uising the RDAP protocol.