Exchange of information: duty to provide foreseeably relevant tax information with confidentiality protections and limited legal exceptions. Competent authorities must exchange foreseeably relevant information, including documents, for implementing the Agreement or administering and enforcing domestic tax laws; such information is secret, may be disclosed only to persons or authorities concerned with tax assessment, collection, enforcement, prosecution, appeals or oversight, and used only for those purposes unless both States' laws allow other uses and the supplying State authorizes them. A State need not act contrary to its laws or supply unobtainable information or disclose trade or public policy sensitive secrets, but must use its information gathering measures to obtain requested information even absent domestic interest, and cannot refuse solely because information is held by banks, nominees or fiduciaries.