Hi, I've downloaded the official XProc RNC grammar from: http://www.w3.org/TR/xproc/schemas/xproc.rnc http://www.w3.org/TR/xproc/schemas/steps.rnc When I open the main file (xproc.rnc) in oXygen, I get the following errors from oNVDL: an "element" pattern containing an "attribute" pattern with a non-null ID-type must have a name class that contains only "choice" and "name" elements conflicting ID-types for attribute "id" from namespace "http://www.w3.org/XML/1998/namespace" of element "catch" from namespace "http://www.w3.org/ns/xproc" Before sending a defect report to the WG, I would like to be sure this is not because a restriction of oNVDL. Best regards, -- Florent Georges http://www.fgeorges.org/