@ricardo Yes, that's the general idea as I understand it. But "1.4 Extended", also as I understand it, includes things that are not in 1.4 and may or may not be in, but certainly likely won't be using the same schema, in a future 1.5.My ultimate goal is to use the current actual standard if at all possible; since that means that anything not covered by the current standard can't be represented, I want to know what, if anything, I'm actually doing in a document that's *not* thus representable.