On the background of a short history of presupposition, the paper focuses on "informative" presuppositions and illustrates their communicative role in texts designed to transmit information such as school textbooks and newspaper articles. It is then claimed that mainstream views of pragmatic presupposition such as Stalnaker's do not deal with informative presupposition satisfactorily and that reference to objective, rather than cognitive, context should be made, as proposed by Gauker. In the framework of an objective conception of context, informative presupposition is explained as an assumption that the receiver should accept.