On 24 Jul 2005, Andrew Gabriel wrote

-snip-

Well, that's because prior to around 1970, it wass illegal to
supply an appliance with a plug in case it was the wrong type,
someone cut it off, and then stuck the resulting loose plug
and exposed flex into a socket. That was just one tiny part of
the problem of having multiple socket types. By 1970 (can't
remember the exact year), judgement was that sockets other than
13A were now sufficiently rare that the law could be changed to
require a BS1363 plug to be fitted to all appliances which were
expected to be plugged in to a socket.

1970 or thereabouts? Are you sure?

I'm positive that when I moved to the UK in 1982, it was still the
practice to sell small appliances without a plug -- that was sold (and
charged for) separately.

(It got my goat: buy an expensive appliance, and then then be charged
an extra quid or so for a plug....cheap *******s....)

--
Cheers,
Harvey