(1) Where the directors of a company are, after making all reasonable enquiries, unable to determine whether a particular profit made before the relevant date is realised or unrealised, they may treat the profit as realised.
(2) Where the directors of a company, after making all reasonable enquiries, are unable to determine whether a particular loss made before the relevant date is realised or unrealised, they may treat the loss as unrealised.
(3) For the purposes of this section the relevant date is -
(a) for companies registered in Great Britain, 22nd December 1980;
(b) for companies registered in Northern Ireland, 1st July 1983.