A marketing order shall define the area of the state to be covered by the order which may be all or any portion of the state; shall contain provisions for establishment of a commodity commission and administration and operation and powers and duties of same; shall provide for assessments as provided for in this chapter and shall contain one or more of the provisions as set forth in RCW 15.66.030. The order may provide that its provisions covering standards, grades, labels and trade practices apply with respect to the affected commodity marketed or sold within such area regardless of where produced. A marketing order may provide that one commodity commission may administer marketing orders for two or more affected commodities, if approved by a majority, as provided in this chapter for the creation of a marketing order, of the affected producers of each affected commodity concerned.