Exchange of information: tax treaty information sharing with confidentiality limits to prevent disclosure of protected secrets. Article 28 requires competent authorities to exchange information and documents necessary to implement the Convention and domestic tax laws for covered taxes, including to prevent fraud or tax evasion, with received information treated as secret; disclosure of information originally secret in the transmitting State is limited to persons or authorities involved in assessment, collection, enforcement, prosecution or appeals and may be used only for those purposes, while authorities must consult to develop conditions and methods for routine or on-request exchanges, subject to limits preventing obligations that conflict with domestic law, unavailable information, or disclosure of trade or other protected secrets.