Search for street names by ZIP code

https://nominatim.openstreetmap.org/search?&country=AT&postalcode=2000&street=stra%C3%9Fe&layer=address&format=json&limit=40 doesn't produce any results. BUT with parameter &city results are delivered: https://nominatim.openstreetmap.org/search?&country=AT&postalcode=2000&city=Stockerau&street=stra%C3%9Fe&layer=address&format=json&limit=40. Why a city name is necessary when a postal code is available. That make no sense. In the most cases &country&postalcode is a unique search criterion. Maybe &county It also appears that not all street names are being returned. The same with here https://nominatim.openstreetmap.org/search?&country=DE&postalcode=81371&city=M%C3%BCnchen&street=stra%C3%9Fe&layer=address&format=json&limit=40 Does not matter with or without parameter &city, no Results are delivered. Json result is "[]" Also whether München or Muenchen is the city name Next topic. How I can search with wildcards. e.g give me all street names in a postal code starting with B% or Br%hof% or L%Weg a.s.o.