Article 23(1) of Regulation No 1008/2008 on common rules for the operation of air services in the Community provides that with rergard to air fares or air rates, optional price supplements shall be communicated in a clear, transparent and unambiguous way at the start of any booking process and their acceptance by the customer shall be on an “opt-in” basis.The German Oberlandesgericht Köln (Higher Regional Court, Cologne) had lodged a reference for preliminary ruling, aksing the ECJ whether the price of a travel cancellation insurance, which is provided by a third party (in this case an insurance company) but which is taken out in relation to, and booked together with, a flight via a website, constitutes an ‘optional price supplement’ within the meaning of Article23(1) of Regulation No 1008/2008, any acceptance of which by the customer must therefore be on an ‘opt-in’ basis.In his opinion delivered today, Advocate General Mazák came to the conclusion that in the light of the general objective of protecting the customer or consumer of air services and the intention to enable customers to compare effectively the prices for air services of different airlines, the concept of ‘optional price supplements’ under Article 23(1) is to be interpreted as covering the costs of services provided by third parties – for example, the cost of taking out a travel cancellation insurance such as that at issue in the main proceedings – where the service and the price to be charged for it are offered together with a flight and can be booked in the same process as the flight and where that price is charged to the customer by the company selling the flight together with the air fare as part of a total price.Full text of opinion in case C-112/11 – ebookers.com available here>>.