DENIC SIDN Labs This document defines data objects for the RESTful Provisioning Protocol (RPP) and sets up the IANA RPP Data Object Registry to describe and catalogue them. Specifically, it details the logical structure, constraints, and protocol operations (including their inputs, outputs, and business logic) for registry resources: domain names, contacts, hosts, organisations, users, and messages, as well as the discovery and profile objects that describe server capabilities. In accordance with the RPP architecture, these definitions focus entirely on the semantics, remaining independent of any specific data representation or media type (e.g., JSON or XML).