Mo. Const. art. X, § 4(b)

Property in classes 1 and 2 and subclasses of those classes, shall be assessed for tax purposes at its value or such percentage of its value as may be fixed by law for each class and for each subclass. Property in class 3 and its subclasses shall be taxed only to the extent authorized and at the rate fixed by law for each class and subclass, and the tax shall be based on the annual yield and shall not exceed eight percent thereof. Property in class 1 shall be subclassed in the following classifications: (1) Residential property; (2) Agricultural and horticultural property; (3) Utility, industrial, commercial, railroad, and all other property not included in subclasses (1) and (2) of class 1. Property in the subclasses of class 1 may be defined by law, however subclasses (1), (2), and (3) shall not be further divided, provided, land in subclass (2) may by general law be assessed for tax purposes on its productive capability. The same percentage of value shall be applied to all properties within any subclass. No classes or subclass shall have a percentage of its true value in money in excess of thirty-three and one-third percent. [Effective - 02 Sep 1982 , see footnote]