Sec. 300.160 (b)

(b) Accommodation guidelines.

(1) A State (or, in the case of a district-wide assessment, an LEA) must develop guidelines for the provision of appropriate accommodations.
(2) The State’s (or, in the case of a district-wide assessment, the LEA’s) guidelines must—
(i) Identify only those accommodations for each assessment that do not invalidate the score; and
(ii) Instruct IEP Teams to select, for each assessment, only those accommodations that do not invalidate the score.