Exchange of information: tax-relevant data may be shared for administration and enforcement, subject to confidentiality and limited exceptions. Competent authorities shall exchange foreseeably relevant information, including documents or certified copies, for applying the Agreement and enforcing domestic tax laws; such information must be treated as secret and used only for tax assessment, collection, enforcement, prosecution, appeals or oversight unless both States' laws and the supplying State authorize broader use. A State is not required to act contrary to its laws or provide unobtainable information, nor to disclose trade or professional secrets or information contrary to public policy; however, information held by banks, nominees or fiduciaries or relating to ownership interests does not by itself permit refusal to supply information.