The discussion in the OSM forum about this issue was rather inconclusive, and there were some arguments against importing the data into OSM, which did not really convince me, but there you go. So, I’ll continue fixing the mistakes manually where I see them. As quite a number of those corrections have accumulated since the last update of the Belgian polygons on PGC, would you be kind enough, whenever you have time, to update them once again? Thanks a lot for all you help!