Nominatim search filtering

Oops.. Thanks, I didn't notice..

But is there a way to filter the results not strictly comply with the required city?

For example http://nominatim.openstreetmap.org/search?street=place&city=Washington&countrycodes=US&format=html

return results from more then one city

I'm afraid not. Your best alternative is to either set &viewbox and &bounded=1 (of course that requires you know the location and size of the city first). Or look at all results to see how close they are to the desired city.

And new problem, I don't understand how it works or it does not work properly?

viewbox without restrict: http://nominatim.openstreetmap.org/search?street=place&city=Washington&countrycodes=US&viewbox=44.86366%2C-127.01294%2C50.05714%2C-111.41235&format=html Four results, but first not in viewbox.

restrict query with bounded=1 http://nominatim.openstreetmap.org/search?street=place&city=Washington&countrycodes=US&viewbox=44.86366%2C-127.01294%2C50.05714%2C-111.41235&bounded=1&format=html and nothing result :(

And same behavior when i use query: http://nominatim.openstreetmap.org/search?q=place%2C+Washington&viewbox=44.86366%2C-127.01294%2C50.05714%2C-111.41235&bounded=1&format=html in this request search results wihout bounded working good, but some other requests without bounded restrict return results also with data out of the viewbox :(

You mixed up latitude and longitude here. The viewbox parameter requires <left>,<top>,<right>,<bottom>. http://nominatim.openstreetmap.org/search?street=place&city=Washington&countrycodes=US&viewbox=-127.012940,50.057140,-111.412350,44.863660&bounded=1

Actually the user interface on that page is misleading. We'll change that now https://trac.openstreetmap.org/ticket/5422