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The Whois Review Team Internationalized Registration Data Expert Working Group is chartered to determine the requirements for internationalized registration data, and produce a data model that matches the requirement.
5. Defining the requirements for IRD
This session given at ICANN49 Singapore on 26 March has useful updates on current work. (link)
6. 2013 Registrar Accreditation Agreement
http://www.icann.org/en/resources/registrars/raa/approved-with-specs-27jun13-en.htm
See WHOIS accuracy program specification for validation and verification.