Except in cases where the user is a natural person acting for non-business purposes, the provisions of article L. 133-1-1, the last two paragraphs of article L. 133-7, articles L. 133-8, L. 133-19, L. 133-20, L. 133-22, L. 133-23, L. 133-25, L. 133-25-1, L. 133-25-2 and the I and III of article L. 133-26 may be waived by contract.