Thanks for the reply. I’m interested mainly in the FX refactoring you mentioned. We are using Forward, NDF, FX option, NDO messages. Is it the case that only the structure of the XSD has changed for these products? The structure of the FPML messages would not have changed? Also, some of the element names have changed, right? If that is the case then I need to do a trivial XSLT on my existing messages to get them from 4.5->5.3 for these product types. What do you think? cheers