Wash. R. App. P. 9.10
If a party has made a good faith effort to provide those portions of the record required by rule 9.2(b), the appellate court will not ordinarily dismiss a review proceeding or affirm, reverse, or modify a trial court decision or administrative adjudicative order certified for direct review by the superior court because of the failure of the party to provide the appellate court with a complete record of the proceedings below. If the record is not sufficiently complete to permit a decision on the merits of the issues presented for review, the appellate court may, on its own initiative or on the motion of a party (1) direct the transmittal of additional clerk's papers and exhibits or administrative records and exhibits certified by the administrative agency, or (2) correct, or direct the supplementation or correction of, the report of proceedings. The appellate court or trial court may impose sanctions as provided in rule 18.9(a) as a condition to correcting or supplementing the record on review. The party directed or permitted to supplement the record on review must file either a designation of clerk's papers as provided in rule 9.6 or a statement of arrangements as provided in rule 9.2 within the time set by the appellate court.
Wash. R. App. P. RAP 9.10