On Sunday, 23 April 2017 15:29:12 UTC+1, John Rumm wrote:
Also there is a (not often used) standard lighting circuit protected
with a 10A MCB, and that is somewhat closer to the 1mm^2 11.5A "in
conduit" rating for the cable.

I think 10A lighting circuits are much more common in commercial premises with banks of fluorescents, but usually 1.5mm cable would be used.

Owain