A retention apparatus, system and method is useful for attaching items, panels or other devices to a rail formed in longitudinal lengths and configured with a cross-sectional profile having multiple cooperating structures between the rail and a channel nut. Self-aligning, mating structures include a recess formed between a tooth and shelf on an interior first channel portion of the rail and a flange of the channel nut with concurrent mating of an anchor latch of the rail and a hook flange on the channel nut. Latching of the channel nut is accomplished initially by compression of the biasing element as the channel nut is inserted and then, upon release, biasing element-induced movement of the channel nut into a latching position. Grounding spikes on the biasing element form electrical contact points between the rail, the clamp and the frame of the solar panel or other device.