Washington Revised Code Title 34. Administrative Law § 34.05.250. Model rules of procedure

The chief administrative law judge shall adopt model rules of procedure appropriate for use by as many agencies as possible. The model rules shall deal with all general functions and duties performed in common by the various agencies. Each agency shall adopt as much of the model rules as is reasonable under its circumstances. Any agency adopting a rule of procedure that differs from the model rules shall include in the order of adoption a finding stating the reasons for variance.