Yellow for 110V, blue for 230V, red for 400V. Other colours for special applications.
16A, 32A, 63A and 125A, 2P+E, 3P+E, 3P+N+E.
You know what I'm talking about. They've been around for 50 years, but no-one can yet agree what to call them.
The official name is "plugs, socket-outlets and...