I agree with Henrik. It will be dangerous to sell devices that depend on the connection of the plug since in Europe there is no way to know where is Live and where is Neutral.

So, regarding the SMPS that Robert posted, I think the main reason for this marking is to dsitiguish fron earth connection. I doubt that internal circuit has any difference in either line L or N, in regard the earth (chassis).

Have reverse engineered such SMPS and is a typical differential EMC filter with capacitors to ground. So can be connected either way.

Ioannis