"Stephen Mawson" wrote:
[snip]

To what extent are the live & neutral interchangeable? Just at the
plug-socket interface?

Just at the plug-socket interface, the plug being able to be inserted either
way up.

They don't care at the socket either. Even sockets on the same wall box can
have some with line at the top, others with line at the bottom.

We used a couple of Italian electricians. Got rid of the first because he
really didn't care and left exposed conductors. The second reminded me if
Adam. He had an apprentice, was thorough and decent to work with. When I
explained that I wanted some things done the British way (use of armoured
cable to the barn) he was happy to comply.