Adding XSLT
You will be doing your users a great favor if you accept the fact that they won't be dealing with just one XML format for each type of document. Assume that transformation is going to be the norm, and make it easy for users. One way you can do this from a functional perspective is to build in support for XSLT. This could be done by giving users the ability to associate a stylesheet with an XML export or import. It will probably be most useful if the association is done on a very specific basis. For example, for an order management and billing system, make the association at the customer level and for each specific type of document. In this fashion the appropriate XSLT transformation could be performed for each document from that customer ...