Exchange of information: confidential tax data may be shared for tax administration and enforcement subject to secrecy and use limits. Article 27 requires competent authorities of the Contracting States to exchange information foreseeably relevant to applying the Agreement or administering and enforcing domestic tax laws, including documents or certified copies. Exchanged information must be treated as secret and disclosed only to persons or authorities involved in tax assessment, collection, enforcement, prosecution, appeals or oversight and used solely for those purposes; public court disclosure is permitted. States are not obliged to act contrary to their laws, to provide unobtainable information, or to disclose protected trade or public policy-sensitive information, but must use information-gathering measures to obtain requested data even without domestic interest, including information held by financial institutions or nominees.