Regional Internet Registries (RIRs) and Domain Name Registries (DNRs)
have historically maintained a lookup service to permit public access
to some portion of the registry database. Most registries offer the
service via the WHOIS protocol [RFC3912], with additional services
being offered via World Wide Web pages, bulk downloads, and other
services, such as Routing Policy Specification Language (RPSL)
[RFC2622].This document records an inventory of registry data objects to
facilitate discussions of registration data objects. The
Registration Data Access Protocol (RDAP) ([RFC7480], [RFC7482],
[RFC7483], and [RFC7484]) was developed using this inventory as
input.
=> Some data elements were not supported by all
RIRs, and some were given different labels by different RIRs. Also,
there were identical labels used for different data elements by
different RIRs. 
 
o All of the 124 domain registries have the object names in their
responses, although they are in various formats.
o Of the 118 WHOIS services contacted, 65 registries show their
registrant contact. About half of the registries (60 registries)
support admin contact information. There are 47 registries, which
is about one third of the total number, that have technical and billing contact information. Only seven of the 124 registries give their abuse email in a "remarks" section. No explicit abuse contact information is provided.
o There are mainly two presentation formats. One is key-value; the
other is data block format.

Most of the domain-related WHOIS information is included in the top
10 data elements. Other information like name server and registrar
name is also supported by most registries.

Nathalie Coupet