This International Standard specifies requirements for indicator lights to show the status of freight-container-handling spreaders and grappler arms. This International Standard is applicable to a) container-handling spreaders with twistlocks for handling unladen and/or laden freight containers, b) grappler (bottom lift) arms for handling semi-trailers and swap bodies, when fitted to — counterbalanced lift trucks, with masts, as defined in 3.1.3.1.1 of ISO 5053:1987, — single side-loading trucks as defined in 3.1.3.1.7 of ISO 5053:1987, — rough terrain trucks, with masts, as defined in 3.1.3.1.8 of ISO 5053:1987, or — variable-reach trucks.