Hi, it seems that although oXygen supports standalone and embedded ISO Schematron it is not able to process ISO Schematron schemas referenced from NVDL. I'm getting the following error: Engine name: Jing Severity: error Description: org.xml.sax.SAXParseException-no implementation available for schema language with namespace URI "http://purl.oclc.org/dsdl/schematron" in oXygen 11. Jirka -- ------------------------------------------------------------------ Jirka Kosek e-mail: jirka@kosek.cz http://xmlguru.cz ------------------------------------------------------------------ Professional XML consulting and training services DocBook customization, custom XSLT/XSL-FO document processing ------------------------------------------------------------------ OASIS DocBook TC member, W3C Invited Expert, ISO JTC1/SC34 member ------------------------------------------------------------------