A general term meaning open publication of information. In the gas industry it is generally used in relation to costs, prices and capacity, where information has traditionally been considered commercially confidential. Costs and prices generally reflect a number of elements, such as production, transportation, storage, service. Transparency generally involves separating out or Unbundling these elements, usually as a result of regulatory requirements. A further step towards transparency involves the publication of the methodology used to calculate the different elements of costs and prices.