Preferential tariff treatment rules require origin-based documentation, protect confidential information, and set authentication procedures for origin declarations. Preferential tariff treatment may be claimed on the basis of an importer's knowledge that goods are originating, provided supporting documentation demonstrates origin. Producer declarations must rely on the producer's information, exporter declarations must be supported by information demonstrating origin, and certificates of origin must be issued on the basis of information received from the exporter or producer. The rule also protects confidential information and establishes an authentication process, including electronic exchange of information, to verify the authenticity of origin declarations.