(a) When a former employee is reemployed, the employing agency shall record on the appointment document the number of weeks of severance pay received (including partial weeks).

(b) If an employee again becomes entitled to severance pay, the agency in which entitlement arises shall recompute the severance pay allowance on the basis of all creditable service and current age and deduct from the number of weeks it would take to exhaust the allowance the number of weeks for which severance pay previously was received.