Trade formulas.

Nothing in section 189.11 shall be construed as requiring the printing of a patented or proprietary trade formula on a label. [S13, §5077-a7; SS15, §4999-a31c; C24, 27, 31, 35, 39, § 3040; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §189.12 ] Referred to in §191.1 , 191.2 , 196.10 , 210.18