Section 11. Taxation of incomes; adoption of federal laws by reference

In enacting any law under section 2 of this article 11, the legislature may at any regular, budget or special session define income by reference to or otherwise adopt by reference all or any part of the laws of the United States as they then exist, and, prospectively, as they may thereafter be amended or enacted, with such exceptions, additions or modifications as the legislature may determine then or thereafter at any such legislative sessions.