Here in Sweden it seems to be true. Both houses I owned had the markers. I had an issue where the online map disagreed with the markers and found out they made a nice film to explain how to resolve problems regarding lot borders: https://www.lantmateriet.se/sv/kartor/vara-karttjanster/Visa...

They even show how they did historically which is super interesting!

Unfortunately changing the borders is super expensive and time consuming though so I didn’t do anything.