Exchange of information: mutual duty to obtain and share foreseeably relevant tax information despite absence of domestic interest. Exchange of Information requires competent authorities to exchange foreseeably relevant information, including documents, for implementing the Agreement and administering or enforcing domestic tax laws; requested States must use their information gathering measures even if they have no domestic interest. Limitations permit refusal where compliance would conflict with domestic law or administrative practice, where information is unobtainable in the normal course, or where disclosure would reveal trade or professional secrets or offend public policy. Information must be treated as secret and used only by authorized persons for tax assessment, collection, enforcement, appeals or oversight, except where both States' laws and the supplying authority permit other uses.