Oh. That is something that did not even cross my mind. Just saw case stickers and did not even check the battery itself. Next time I open the machine I’ll check CE marking / stickers on the battery itself. Still more convenient to have them on the replacement cover so it does not have to be opened if inspected.
I agree that it’s not common. Regulation is in place for air travel in Europe, but they are more worried about cheap Chinese power banks - not laptops. Personally have never experienced or seen anything, but am overly cautious since it would be a stupid detail to trip over, if it can be mitigated that easily.