One of ISO 19650's defined roles: the Appointing Party is the organization commissioning the work - usually the client - responsible for setting the EIR and ultimately deciding what information it needs. Every other role in the standard's terminology is defined relative to this one: the Appointing Party appoints a Lead Appointed Party, who in turn may appoint further Task Teams.

Knowing these role names matters mainly when reading an ISO 19650-compliant contract or BEP directly - the standard uses them precisely and consistently, and the terminology can otherwise read as needlessly formal for what is, in plain language, simply "the client."'