classified classify data information key lock locked secure secured advice alert announcement beware black camera cctv communicating communication constant continuous electronic informing lookout notice observation observe protected protection safety security sign surveillance under-observation video warning warning-sign watch watched aware awareness direction directions informative observant regulations rules rust rusty visitors white wood wooden blue camera-surveillance closed-circuit-tv community external light lighting monitoring public security-camera surveillance-camera video-camera enter entrance entry cripple invalid pictogram road street closed gate gates mesh statement