Seasonal marketing regulations shall not extend beyond the marketing regulatory authorizations which are specified in the marketing order or agreement concerned, or modify or change the language of such marketing order or marketing agreement by adding to, or subtracting from, such marketing order or agreement any of the marketing regulatory authorizations which are classed in Article 13 (commencing with Section 59021) of this chapter as major amendments, or modify the language of any marketing order or agreement for the purpose of clarification as provided in Article 14 (commencing with Section 59051) of this chapter for minor amendments.