For purposes of RCW 46.20.055, an applicant for a driver's instruction permit may demonstrate enrollment in a traffic safety education course offered by a licensed driver training school, or by a public or private school recognized by the superintendent of public instruction, by submitting written proof of enrollment indicating that the driver training course has already begun or will begin within ten calendar days of the date of the application. The proof of enrollment must be in a form that is approved by the department and bear the signature of a licensed driver training instructor or driver training school owner, or that of a public or private school instructor certified to teach a driver training course by the superintendent of public instruction.