@rhelune @infobeautiful Yes, belgian are more logical with numbers than french are.
If you order a "demi" (half of a pint) of beer in 
you will have 25cl because at some point decided a pint is 50cl.
Meanwhile in 
a pint is 1L (100cl) so if you order a "demi" you will have 50cl - half a Litre - which make more sense.
(Or maybe it's just a ruse to get french tourist buy more - that would be funny)