(1) Nonprofit vocational rehabilitation programs may apply for a subprevailing wage certificate authorizing the employment of one or more workers with a developmental disability at less than the prevailing rate. An application for each worker shall be filed with the office of the industrial statistician not less than annually upon forms approved by the director or an authorized representative of the director.

(2) The application shall be signed jointly by the employer, the worker with a disability for whom such application is being made, and by the parent or guardian of the worker with a disability except as otherwise authorized by the director or an authorized representative of the director.