Thanks all - I didn't mention that the socket would be in a space
above the top of the airing cupboard ( lined with wooden wainscotting
) so won't be visible, or accessible easily, so maybe the 13A socket
with a Dyno'd "Lighting Only" label plus a 1A FCU is the way to go.

OTOH, it needs to have some accessibility to change the fuse. Also, a label
near the lighting indicating the position of the non-obvious FCU may be in
order.

Christian.