Hi Pascal! Glad to hear you, i like very much HDYC, it's very useful for reviewing OSM edits! About the data added by me, yes, partially this data is an import, it was reworked by me, and adapted to OSM parameters. The data is from national cadastral map. About the copyright, the data was downloaded from the WFS Geoserver and can be downloaded freely by anyone, because there are no limitations for public access. Thanks for interest and have a nice!