1. The Member States may permit the purchase price or production cost of stocks of goods of the same category and all fungible items including investments to be calculated either on the basis of weighted average prices or by the "first in, first out" (FIFO) method, the "last in, first out" (LIFO) method, or some similar method.
2. Where the value shown in the balance sheet, following application of the methods of calculation specified in paragraph 1, differs materially, at the balance sheet date, from the value on the basis of the last known market value prior to the balance sheet date, the amount of that difference must be disclosed in total by category in the notes on the accounts.