Tax coverage under a bilateral DTAA defines which national income taxes and similar subsequent taxes fall within the treaty's scope. The Article specifies treaty-covered taxes: for India, income-tax (with surcharges) and surtax; for Italy, personal, corporate and local income taxes, including withholding collections. It further provides that the Convention applies to any identical or substantially similar taxes introduced later, and requires the competent authorities to annually notify each other of changes to taxation laws and to furnish copies of relevant enactments and regulations.