/** Tablet width threshold for responsive design */
    protected static final int TABLET_WIDTH = 768;

    /** HTTP header name for content disposition */
    protected static final String CONTENT_DISPOSITION = "Content-Disposition";

    /** Cache key for highlighted cache content */
    protected static final String HL_CACHE = "hl_cache";

    /** Cache key for search queries */

				"image/x-xpixmap",
				"image/x-xwindowdump",
				"message/cpim",
				"message/delivery-status",
				"message/disposition-notification",
				"message/example",
				"message/external-body",
				"message/global",
				"message/global-delivery-status",
				"message/global-disposition-notification",
				"message/global-headers",
				"message/http",
				"message/imdn+xml",
				"message/news",