The value of data models in general and information models in specific has been evaluated by many scientific papers. UML as one modelling notation has documented its value as a foundation for precise specifications. Analyzing implementation guides for data exchange, they rarely include or are based on information models but simple data sets, if at all, as simple technical representation thereof. This paper wants to argue in favor of information models as a basis for creating interoperability specifications using a quite simple example and to include – or at least reference – them when providing implementation guides. The reader is invited to transfer this example to even more complex scenarios.