@Override
    public boolean getFeature(String featureId)
            throws SAXNotRecognizedException, SAXNotSupportedException {
        if ((FEATURE + "validation").equals(featureId)) {
            return false;
        }

        // external entities (both types) are optionally included
        if ((FEATURE + "external-general-entities").equals(featureId)) {
            return extGE;
        }
        if ((FEATURE + "external-parameter-entities").equals(featureId)) {
            return extPE;
        }

        // element/attribute names are as written in document; no mangling
        if ((FEATURE + "namespace-prefixes").equals(featureId)) {
            return xmlNames;
        }

        // report element/attribute namespaces?
        if ((FEATURE + "namespaces").equals(featureId)) {
            return namespaces;
        }

        // all PEs and GEs are reported
        if ((FEATURE + "lexical-handler/parameter-entities").equals(featureId)) {
            return true;
        }

        // default is true
        if ((FEATURE + "string-interning").equals(featureId)) {
            return stringInterning;
        }

        // EXTENSIONS 1.1

        // always returns isSpecified info
        if ((FEATURE + "use-attributes2").equals(featureId)) {
            return true;
        }

        // meaningful between startDocument/endDocument
        if ((FEATURE + "is-standalone").equals(featureId)) {
            if (parser == null) {
                throw new SAXNotSupportedException(featureId);
            }
            return parser.isStandalone();
        }

        // optionally don't absolutize URIs in declarations
        if ((FEATURE + "resolve-dtd-uris").equals(featureId)) {
            return resolveAll;
        }

        // optionally use resolver2 interface methods, if possible
        if ((FEATURE + "use-entity-resolver2").equals(featureId)) {
            return useResolver2;
        }

        if ("http://xml.org/sax/features/unicode-normalization-checking".equals(featureId)) {
            return checkNormalization;
        }

        throw new SAXNotRecognizedException(featureId);
    }
<b>SAX2</b>: Tells the value of the specified feature flag.

@exception SAXNotRecognizedException
               thrown if the feature flag is neither built in, nor yet
               assigned.
src/nu/validator/gnu/xml/aelfred2/SAXDriver.java