A mounting arrangement for a light or other object includes a clamping arrangement, or a keying arrangement, or both a clamping and a keying arrangement for mounting to different mounting rails having different keying features. The clamping arrangement includes a fixed clamp member and a movable clamp member that is movable towards and away from the fixed clamp member and is biased towards the fixed clamp member, so as to grip a mounting rail therebetween. The keying arrangement employs interchangeable keying members that may be disposed in a recess of the light or other object and that may have different keying features for use with mounting rails having corresponding keying features.