Article 22 Allocation declaration to be valid after alteration of amount of pension

Where a person has been informed, in pursuance of Rule 17 of these Rules, that an allocation declaration made by him is valid, that declaration shall remain valid, unless cancelled or amended by him in the manner and within the period permitted by these Rules, notwithstanding that, as the result of a subsequent alteration of the amount, or estimated amount, of his pension, the amount of pension to be surrendered no longer complies with Rule 6 of these Rules.