@Override
    public void startDocument() throws SAXException {
        alreadyWarnedAboutRdf = false;
        alreadyWarnedAboutOpenMath = false;
        alreadyWarnedAboutInkscape = false;
        alreadyWarnedAboutSvgVersion = false;
    }
@see nu.validator.checker.Checker#startDocument()
src/nu/validator/checker/UncheckedSubtreeWarner.java