Reply to Keith Schultz: Starting near the end of your response, Keith: 3. Given that we share a primary interest in books (text), it makes sense that the XML should conform to the XHTML doctype. WHY? For example epub does require any adherence to the XHTML, Just to XML version 1.0 !!! Wrong. XHTML IS specified! Besides HTML is a backwater and the W3C would like it to disappear. 2. Easy! Express your markup scheme in terms of XML! XML is not a particular mark scheme. You write the "scheme" in XML. Though term scheme is used differently in XML. But XHTML _IS_ XML, specialised for text, so why not use it. 4. For that matter using any other markup an XSLT can be used to get to XHMTL. I think that you are agreeing with me. And note that one option is to back-convert to prettified text, or even zml. And the XML can be used to generate other content, like a TOC and endnotes. Regards, John