30  – Connects to a RED wire, permanently Live +
50 – Unfused High Current Switchable Circuit (Used for starter switchable wire)
56, 56a, 56b – A High Current circuit switchable Circuit, (For example Sidelights and low and High Beam trigger Terminals)
15 – Connects to a BLACK wire, is used for on IGNITION live circuits, (For example Coil and Windscreen wipers.)
31, 31b – Usually BROWN wire, is used primarily for earthing a circuit
85, 86, 87, 87a – Typically used for Low Current / High Current Trigger Circuit, Heated window etc.