RCW 46.20.105
RCW 46.20.105: Identifying types of licenses and permits.
(1) The department may provide a method to distinguish the driver's license of a person who is under the age of twenty-one from the driver's license of a person who is twenty-one years of age or older. (2) An instruction permit must be identified as an "instruction permit" and issued in a distinctive form as determined by the department. (3) An intermediate license must be identified as an "intermediate license" and issued in a distinctive form as determined by the department.