Tax treaty scope: specifies covered direct taxes and extends to identical or substantially similar successor taxes with mutual notification. Article 2 limits the Convention to Japan's income tax and corporation tax and India's income tax (including surcharges), and extends the Convention to identical or substantially similar taxes introduced later. It requires the competent authorities to notify each other of substantial changes in taxation laws within a reasonable period, providing a procedural mechanism to maintain reciprocal awareness of changes affecting the Convention.