In article ,
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5A round pin sockets are an ancient design, but they weren't normally run
via a light switch in times past. However with few rules people could
have done almost anything. Nowadays its standard practice, albeit not
very popular, to put 5A skts on lighting circuits. Modern sockets must
have shutters.

Certainly as a design they have been around for some time, but in India,
for example, they are the standard plug. They used to be very common in
the "wall light switch" mode, but got forgotton when 13A sockets appeared.
they are now coming back into favour.

Incidentally, the First edition of the IEE Wiring Regulations was published
in 1882.

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