34 C.F.R. § 303.25
(a) Native language, when used with respect to an individual who is limited English proficient or LEP (as that term is defined in section 602(18) of the Act), means—
(b) Native language, when used with respect to an individual who is deaf or hard of hearing, blind or visually impaired, or for an individual with no written language, means the mode of communication that is normally used by the individual (such as sign language, braille, or oral communication).
(Authority: 20 U.S.C. 1401(20))