"Parent" means the mother, father, or legally designated guardian of a person with a disability. "Parent" can also mean the person with a disability when that person reaches 18 years of age, and if a legal guardian has not been appointed by appropriate court proceedings. The term "parent" also includes a "surrogate" for the parent under the State Board Revised Policy for the Appointment of Surrogate Parents for Special Education Services (2/12/2003).