Salut Régis, Thanks for your answer and link. I'm already shipping QGIS with custom INI file, what I'm looking for is the parameter to set the default project format. And then put it in my QGIS3.ini. Or did I miss something in your link? Rémi -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-Developer-f4099106.html