If the secretary of state accepts and files an initiative or referendum petition upon its being submitted for filing or if he or she is required to file it by the court, he or she shall, in the presence of the person submitting such petition for filing if he or she desires to be present, arrange and assemble the sheets containing the signatures into such volumes as will be most convenient for verification and canvassing and shall consecutively number the volumes and stamp the date of filing on each volume.
RCW 29A.72.210