nominatim (the engine behind the search on the map on osm.org) builds hierarchies out of the OSM data and does not return results based on the unprocessed OSM data. For example if there is a house with just a number it will match that with the nearest road and so on, without doing such processing you will not get the same results. Back to your question: osmconvert supports clipping on a bounding boc box or a polygon, see http://wiki.openstreetmap.org/wiki/Osmconvert#Applying_Geographical_Borders gicing the OSM wiki section on ["Applying Geographical Borders"][1]. Using a bounding box is likely to be simplest for starters (you already have one displayed in the picture you supplied). [1]: http://wiki.openstreetmap.org/wiki/Osmconvert#Applying_Geographical_Borders

nominatim (the engine behind the search on the map on osm.org) builds hierarchies out of the OSM data and does not return results based on the unprocessed OSM data. For example if there is a house with just a number it will match that with the nearest road and so on, without doing such processing you will not get the same results. Back to your question: osmconvert supports clipping on a bounding boc or a polygon, see http://wiki.openstreetmap.org/wiki/Osmconvert#Applying_Geographical_Borders gicing a bounding box is likely to be simplest for starters (you already have one displayed in the picture you supplied).