The main portion of ASML’s revenue is derived from contractual arrangements with its customers that have multiple deliverables, which mainly include the sale of our systems, installation and training services and prepaid extended and enhanced (optic) warranty contracts. For each of the specified deliverables ASML determines the selling price by using either vendor specific objective evidence (‘VSOE’), third party evidence (‘TPE’) or by best estimate of the selling price (‘BESP’). When the Company is unable to establish relative selling price using VSOE or TPE, the Company uses BESP in its allocation of arrangement consideration. The total arrangement consideration is allocated at inception of the arrangement to all deliverables on the basis of their relative selling price. The revenue relating to the undelivered elements of the arrangements is deferred at their relative selling prices until delivery of these elements. Revenue from installation and training services is recognized when the services are completed. Revenue from prepaid extended and enhanced (optic) warranty contracts is recognized over the term of the contract.Foreign currency risk management The Company uses the euro as its invoicing currency in order to limit the exposure to foreign currency movements. Exceptions may occur on a customer by customer basis. To the extent that invoicing is done in a currency other than the euro, the Company is exposed to foreign currency risk. It is the Company’s policy to hedge material transaction exposures, such as forecasted sales and purchase transactions and material net remeasurement exposures, such as accounts receivable and payable. The Company hedges these exposures through the use of foreign exchange contracts. As of December 31, 2012, shareholders’ equity includes EUR 4.9 million gain (net of taxes: EUR 4.3 million gain; December 31, 2011: EUR 4.4 million loss) representing the total anticipated gain to be released to sales, and EUR 6.0 million loss (net of taxes: EUR 5.3 million loss; December 31, 2011: EUR 10.3 million gain) to be charged to cost of sales, which will offset the EUR equivalent of foreign currency denominated forecasted sales and purchase transactions.