Modern information systems usually exploit numerous XML formats for communication with other systems. There are, however, many potential problems hidden.
This includes the degree of readability, integrability and adaptability of the XML formats. In the first part of this paper we demonstrate the problems on a real-world application - the National Register of Public Procurement in the Czech Republic.
In the second part we show how we can improve readability, integrability and adaptability of the XML formats of this system with a conceptual model for XML we have developed in our previous works. Finally, we generalize our experience gained into a methodology which can be applied in any other problem domain.