i have some experience with another such protocol, for customs , to/from EU. About 15 years ago, it was made mandatory (in Bulgaria). A friend of mine suggested

i have some experience with another such protocol, for customs , to/from EU. About 15 years ago, it was made mandatory (in Bulgaria). A friend of mine suggested we make a software for filling those forms, and handle the XML-message-passing-and-signing and FSMs and all-that, and sell it. Took me few months, did it, then got few clients.. which used it for about 2 years, with updates of rules once in a while, and then one day the government published a free pdf-like generator for those XMLs, and we had to close - regardless of other niceties, people needed mostly the forms, and the new free ones were good-enough - and kept updated.