What is the significance of the proviso added to this article on constitutional amendments?
The significance of the proviso added to this article on constitutional amendments is that certain specific changes in the Constitution require additional ratification by at least half of the State Legislatures before being presented for assent by the President. These changes include those concerning certain articles related to states' representation in Parliament, specific chapters and lists within Parts V, VI, and XI of the Constitution, and provisions regarding the amendment procedure itself.