code: public static DTDElement createDefined(ReaderConfig cfg, Location loc, PrefixedName name,
                                             StructValidator val, int allowedContent)
      {
          if (allowedContent == XMLValidator.CONTENT_ALLOW_UNDEFINED) { // sanity check
              ExceptionUtil.throwInternal("trying to use XMLValidator.CONTENT_ALLOW_UNDEFINED via createDefined()");
          }
          return new DTDElement(loc, name, val, allowedContent,
                                cfg.willSupportNamespaces(), cfg.isXml11());
      }
docs: Method called to create an actual element definition, matching
  an ELEMENT directive in a DTD subset.