Section 10-8.1 - Rule against perpetuities; time at which permissible period begins(a) Where an estate is created by an instrument exercising a power of appointment, the permissible period of the rule against perpetuities begins: (1) In the case of an instrument exercising a general power which is presently exercisable, on the effective date of the instrument of exercise.(2) In all other cases, at the time of the creation of the power.(b) Where the creator of a trust reserves to himself an unqualified power to revoke, the permissible period of the rule against perpetuities begins when the power to revoke terminates by reason of the death of the creator, by a release of such power or otherwise.