Set on and set off of allocable surplus permits limited carry forward to meet bonus shortfalls and prescribes application order. Section 36 provides that where allocable surplus exceeds maximum bonus requirements the excess may be carried forward subject to a prescribed utilisation limit for payment of bonus in succeeding accounting years; where surplus is insufficient to meet minimum bonus the deficiency shall be carried forward for set off in succeeding accounting years; Central Government rules may apply the same principle to other cases; earliest carried amounts are to be applied first.