Wash. Super. Ct. Civ. Arb. R. SCCAR 5.2
At least 14 days prior to the date of the arbitration hearing, each party shall file with the arbitrator and serve upon all other parties a statement containing a list of witnesses whom the party intends to call at the arbitration hearing and a list of exhibits and documentary evidence, including but not limited to evidence authorized under rule 5.3(d). The statement shall contain a brief description of the matters about which each witness will be called to testify, and whether that testimony is anticipated to be provided in writing, in person, or by telephone. Each party, upon request, shall make the exhibits and other documentary evidence available for inspection by other parties. A party failing to comply with this rule or failing to comply with a discovery order may not present at the hearing the witness, exhibit, or documentary evidence required to be disclosed or made available, except with the permission of the arbitrator.
Wash. Super. Ct. Civ. Arb. R. SCCAR 5.2