The group adopted International Financial Reporting Standards (IFRS) with effect from 1 January 2005. Financial information for 2003 and 2004 has been restated to reflect the adoption of IFRS, as has the balance sheet at 1 January 2003, BP's date of transition to IFRS. BP chose not to adopt International Accounting Standard No. 39 'Financial Instruments: Recognition and Measurement' (IAS 39) until 1 January 2005, so financial assets and liabilities, including derivatives, are reported on the basis of UK generally accepted accounting practice (UK GAAP) for 2003 and 2004. The balance sheet at 1 January 2005 is also presented to show the effect of adopting IAS 39. The financial information for 2002 has not been restated for IFRS and remains on the basis of UK GAAP.

(1) Replacement cost profit before interest and tax includes equity-accounted interest and tax
(2) Replacement cost profit is before inventory holding gains and losses.
(3) The Global Indicator Refining Margin (GIM) is the average of regional industry indicator margins, which we weight for BP's crude refining capacity in each region. Each regional indicator margin is based on a single representative crude with product yields characteristic of the typical level of upgrading complexity. The refining margins are industry-specific rather than BP-specific measures, which we believe are useful to investors in analysing trends in the industry and their impact on our results. The margins are calculated by BP based on published crude oil and product prices and take account of fuel utilization and catalyst costs. No account is taken of BP's other cash and non-cash costs of refining, such as wages and salaries and plant depreciation. The GIM may not be representative of the margins achieved by BP in any period because of BP's particular refining configurations and crude and product slate.
(4) Operating capital employed is total assets (excluding goodwill) less total liabilities, excluding finance debt and current and deferred taxation.
(5) Operating capital employed revaluation adjustment consequent.
(6) UK area includes the UK-based international activities of Refining and Marketing.
(7) Crude oil and natural gas liquids.
(8) Cost of supply comprises exploration expense, lifting costs and depreciation, depletion and amortization.