Wash. Admin. Code § 388-02-0480
(1) Burden of proof is a party's responsibility to:
[Statutory Authority: RCW 34.05.020, 34.05.220. WSR 11-04-074, § 388-02-0480, filed 1/31/11, effective 3/3/11. Statutory Authority: RCW 34.05.020. WSR 00-18-059, § 388-02-0480, filed 9/1/00, effective 10/2/00.]