(A) For purposes of this rule:
(1) "Base allowance" means the benefit amount due a benefit recipient on the later of July 1, 1979 or the effective date of such benefit, as adjusted pursuant to this rule. A base allowance excludes subsequent allowances for cost-of-living pursuant to section 3309.374 of the Revised Code, reimbursements for medicare part "B" pursuant to section 3309.69 of the Revised Code, or additional annuity payments pursuant to section 3309.47 of the Revised Code.
(2) "Benefit" means a periodic payment under an allowance, pension, or benefit granted under Chapter 3309 of the Revised Code, other than an annuity paid under section 3309.341 of the Revised Code.
(3) "Benefit amount" means the amount due a benefit recipient on the effective date of such benefit.
(4) "Benefit recipient" means an age and service retirant, disability benefit recipient, or a beneficiary as defined in section 3309.01 of the Revised Code, who is receiving monthly benefits due to the death of a member, age and service retirant or disability benefit recipient.
(B) A base allowance upon which a cost-of-living is calculated shall be adjusted when any of the following occur:
(1) The enactment of any statutory ad hoc allowance increase but only if such statutory authority provides that such increase become part of the base allowance.
(2) Recalculation of a retirant's benefit due to a change in a plan of payment as permitted in section 3309.46 of the Revised Code.
(3) Recalculation of a benefit recipient's benefit amount after an audit.
(4) If a benefit recipient waives any portion of a benefit amount pursuant to section 3309.662 of the Revised Code, the base allowance shall be the portion being paid. If a waiver is revoked, the base allowance shall be the amount allowed under this rule.