Hi Rodolfo, all, > Nevertheless, I would make the declaration > of the core namespace required in the conformance clause. +1. > From XML point of view, declaring the > namespace is optional. Just to clarify though: Should/Must an XLIFF 2.0 processor be able to process this: <xliff version="2.0" srcLang="en"> <file> <unit id="u1"> <segment> <source>text</source> </segment> </unit> </file> </xliff> I'm asking because without a namespace declaration that document could be any format that just happens to start with <xliff>. Cheers, -ys