IAS 21-Foreign Exchange rate

A purchase, for example, will be recorded at the rate of exchange at the date of the transaction - so there is not gain or loss arising on the "expense" but on the settlement of the liability. Exchange differences arising when monetary items (e.g. a liability) are settled are reported in profit or loss in the period. Whether such gains/losses merit separate disclosure (rather than be included in cost of purchases, for example), I suggest would depend on materiality.