Another example of a really dumb nomenclature scheme. A simple letter tells you nothing of interest about the plug type, e.g. number of pins, pin size/shape/spacing, etc.

And what happens when the number of plugs in use becomes 27? Will they start using lower case letters to ensure further confusion?

Also, there are still plenty of older homes with sockets that look like type A with equal-size slots. I don't see that style on this list.

Some (type C & L) look as if the plug could be inserted in more than one orientation.