an addressing unit 342 for accessing specified data from local or remote sources e g database 330 the presentation manager 340 further has a media handler 341 for allocation of medium or media appropriate for a presentation according to the format specification the media handler 341 typically manages media and allocation of media to messages for presentation the media handler 341 can further determine a system state a system state can specify messages being processed and allocated to a medium messages having been interrupted or deleted or queued for later presentation the presentation manager 340 further has a transcoding unit 343 for transcoding information that resides at database 330 originally stored in a format not conforming to the specified preferred format for example if input data indicates that the driver of a vehicle is likely not benefited from a very detailed map the navigation manager includes in the format specification directives to replace certain objects with abstractions thereof e g obtained from a symbol database 330 the media handler 341 in consideration of system status and priorities of incoming messages determines actions e g that a new message shall be overlaid on an already occupied medium or that an ongoing presentation shall be temporarily interrupted for presentation of the new message or that a free medium shall be allocated to the new message the media.