Purty much.
Think in use euro measure is 100lt flat, since your 1/2 barrel/keg is 50lt. So a hectolitre
Weird thing is in the US we mostly use 1/6 barrels at 20lt for our small kegs, and our quarter barrels are 30lt.
Which does not line up at all with the standard for the barrel measure. So it doesn’t even justify itself based on working with the packaging. It’s only an easy way to calculate things for the one format.