1. Process for storing and accessing data in databases of a computerized travel reservation system, characterized by the fact that for each type of information to be stored, there are created rules associating: a set of criteria defining the trips to which the information is applicable, a content representing the value of the information to be applied; the set of criteria of a rule comprising a pair of markets with a market of origin which is defined as the geographic zone of departure of the trip and a destination market which is defined as the geographic zone of arrival of the trip, the defined markets are stored in a database, the created rules are stored in a database.