void doctypeDecl(String name, String publicId, String systemId)
            throws SAXException {
        lexicalHandler.startDTD(name, publicId, systemId);

        // ... the "name" is a declaration and should be given
        // to the DeclHandler (but sax2 doesn't).

        // the IDs for the external subset are lexical details,
        // as are the contents of the internal subset; but sax2
        // doesn't provide the internal subset "pre-parse"
    }
<b>SAX2</b>: Assigns the specified property. Like SAX1 handlers, these
may be changed at any time.
src/nu/validator/gnu/xml/aelfred2/SAXDriver.java