Wash. Rev. Code § 7.25.020
A complaint shall be prepared and filed in the superior court by such government entity setting forth such ordinance or resolution and that it is the purpose of the plaintiff to issue and sell bonds as stated therein and that it is desired that the right of the plaintiff to so issue such bonds and sell the same shall be tested and determined in said action. In said action all interested parties shall be deemed to be defendants. The title of the action shall be "In re (name of bond issue)." Upon the filing of the complaint the court shall, upon the application of the plaintiff, enter an order naming one or more interested parties upon whom service in said action shall be made as the representative of all interested parties, except such as may intervene as herein provided, and in such case the court shall fix and allow a reasonable attorneys' fee in said action to the attorney who shall represent the representative interested parties as aforesaid, and such fee and all taxable costs incurred by such representative interested parties shall be taxed as costs against the plaintiff: PROVIDED, That if the interested parties appointed by the court shall default, the court shall appoint an attorney who shall defend said action on behalf of all interested parties, and such attorney shall be allowed a reasonable fee and taxable costs to be taxed against the plaintiff: PROVIDED FURTHER, That after filing the complaint, the plaintiff shall twice place a notice in a newspaper of general circulation within the boundaries of the government entity, stating the title of the action, informing the interested parties that the action has been commenced testing the validity of the bonds, and stating that any interested parties, as that term is defined herein, may intervene in such action and be represented therein by his or her own attorney. Thereupon, any interested parties who desire to intervene must apply to the court to intervene within ten days after the second publication of the notice.
RCW 7.25.020