Notwithstanding any conditions on which an executive committee may have consented to the inclusion of any financial instruments in the list referred to in section 14, any new conditions or any amendment of the existing conditions which may from time to time be imposed or effected by the executive committee, may, in accordance with the rules, be applied by the executive committee also to financial instruments in respect of which consent was granted prior to the imposition or amendment of such conditions, by prior notice in writing to the person who issued the financial instruments in question.