A device class-specific filter element, the content/link will not be displayed if the target device class matches the value of one of the ignoreClass elements. A device-specific filter element, the content/link will not be displayed if the target device matches one of the ignoreDevice elements. A device class-specific filter element, the content/link will be displayed if the target device class matches one of the useDevice elements. A device-specific filter element, the content/link will only be displayed if the target device matches one of the useDevice elements.