This document specifies requirements for indicator lights to show the status of freight-container-handling spreaders and grappler arms. It 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: — counterbalance lift trucks, with masts, as defined in ISO 5053‑1:2015, 3.3; — rough terrain trucks, with masts, as defined in ISO 5053‑1:2015, 3.7; — non-stacking low-lift straddle carriers, as defined in ISO 5053‑1:2015, 3.18; — stacking high-lift straddle carriers, as defined in ISO 5053‑1:2015, 3.19; — variable-reach trucks, as defined in ISO 5053‑1:2015, 3.20; — rough-terrain variable-reach trucks, as defined in ISO 5053‑1:2015, 3.21; — variable-reach container handlers, "reach stackers", as defined in ISO 5053‑1:2015, 3.23; — counterbalance container handlers, as defined in ISO 5053‑1:2015, 3.24.