Exchange of information expanded to mandate cross-border tax data sharing with confidentiality and use limits for tax enforcement. The Protocol replaces Article 26 to require exchange of foreseeably relevant tax information (including documents), mandates confidentiality and restricted use by tax and judicial authorities, limits obligations where domestic law or public policy prevents disclosure, and clarifies that bank secrecy is not alone a ground for refusal. An added Protocol paragraph extends Article 26 to income-related regulatory enforcement and permits use of exchanged information for those regulations without further conditions; the Amending Protocol enters into force after mutual diplomatic notification and forms part of the Convention.