2013 ORS § 316.364¹
Flesch Reading Ease Score form instructions

(1) The instructions to an individual state income tax return form shall have a total Flesch Reading Ease Score of 60 or higher.

(2) As used in this section:

(a) Flesch Reading Ease Score means 206.835 [bad link] - (x + y) where x equals average sentence length multiplied by 1.015 [bad link] and y equals average word length multiplied by 84.6 [bad link].

(b) Average sentence length means the total number of words in the instructions to the state income tax return form divided by the total number of sentences in the instructions.

(c) Average word length means the total number of syllables in the instructions to the state income tax return form divided by the total number of words in the instructions. [1977 c.736 §3]