Foreign exchange fluctuation rule: capitalise exchange-rate variation into asset cost, adjusting acquisition cost for tax purposes. Capitalisation of foreign exchange fluctuation requires that variations in liability from exchange-rate changes on payment for an asset in foreign currency be computed as A = B - C (B: amount paid in Indian currency during the tax year; C: liability in Indian currency at acquisition) and added to or deducted from the actual cost of the asset, capital expenditure, or cost of acquisition; where an authorised dealer contract fixes a future exchange rate, the portion available to discharge the liability is computed with reference to that rate.