Alternative rules for valuing certain assets under the Companies Act. These rules modify the historical-cost convention. According to the modified rules intangible assets may be valued at current cost (with the exception of goodwill). Tangible fixed assets may be included at market value, determined as at their last valuation date, or at current cost. Fixed-asset investments may be valued at market value, determined as at their last valuation date, or at a value determined on any basis considered by the directors to be appropriate to the circumstances. Current-asset investments and stock may be included at current cost, unless the net realizable value is lower, in which case this must be used. Any permanent diminution in value must be provided for. Accounts prepared under the alternative accounting rules are described as being prepared under the modified historical-cost convention.