Proper query of OSM APIs and 'polygons.openstreetmap.fr'

[mmd]

Same question was also posted here:

• http://gis.stackexchange.com/questions/221219/proper-query-of-osm-apis
• https://help.openstreetmap.org/questions/53527/how-to-query-osm-apis-and-polygonsopenstreetmapfr-properly