@tilton Yep. It's dumber than hell. Though at least the wire itself has the semi-excuse of "how often are you doing math with the cross-sectional area" vs an abstract number and some lookup tables should you need to do that math for whatever reason. Some US electrical practices are dumb as a box of rocks, but other countries generally also have their own Weird Things with electrical stuff that we're weirded out by as well. Like multi-circuit RCDs where a trip can take out an entire floor, instead of one smaller RCD per circuit (especially with 240v meaning more 'low-power' stuff can fit on one circuit). Or specifically in the UK, ring mains. Those are Weird.