Given that systems typically hold data in some kind of code model before it is serialized to a final character encoded format required by the government such as XML, CSV (yes, right) or JSON, is there more reason to serialize it as XML or as another format such as CSV or JSON? Or is serialization to JSON so commonplace that there is little reason to look any further if given the choice? I could understand it if serialization to JSON poses a problem when the government puts necessary constraints on that JSON. Is the understanding of the practicalities of the possibilities for constraining the final, transferred data/document a reason to stick with XML? UTF-*, escaping, choices of alternatives in the text syntax, etcetera?