So, generally, revaluation adjustments are to be recognized in other
comprehensive income and accumulated in equity under the heading of revaluation
surplus. If a revalued asset is subsequently found to be impaired, the impairment
provision is first offset against the revaluation surplus, and only when that has been
exhausted is it expensed. Equally, if an asset carried at historical cost had been
impaired, but was subsequently revalued above historical cost, because of some
dramatic change in economic circumstances, the previous impairment provision would
flow back through profit, and only the increase above historical cost would be
recognized in other comprehensive income and accumulated in equity.