40.—(1) This paragraph applies to assets included under assets items E.I, II and III (debtors) and F.III (cash at bank and in hand) in the balance sheet.
(2) If the net realisable value of an asset to which this paragraph applies is lower than its cost the amount to be included in respect of that asset is the net realisable value.
(3) Where the reasons for which any provision for diminution in value was made in accordance with sub-paragraph (2) have ceased to apply to any extent, that provision must be written back to the extent that it is no longer necessary.