This is a limitation of the plugin. It accepts ASCII characters only. Try changing special characters by it's nearest ASCII equivalent: ä by a etc. Otherwise, use another Geocoding method.
See here for details:
Unfortunately, these aren't all documented.
accuracy is an alias for "importance". There is some commentary on how importance is calculated in the osm-search/wikipedia-wikidata readme
Nominatim can use the page ranking of Wikipedia pages to help indicate the relative importance of osm features. This is done by calculating an importance score ...
This is all nonsense. Classless IP (CIDR) distribution has an impact on the 'hierarchical' approach. An ISP is assigned a block - in my case /19 to /22s from various larger blocks. We cover two states and move blocks between states often. NAT also has an impact. The best you are going to get is (a) what the ISP updates and is not overwritten (which ...
Since QGIS 3.18, no need for third party to geocode from Nominatim or Google Maps (not demonstrated below as you need an API key) as there is a class dedicated for this purpose in PyQGIS
Below, a recipe for Nominatim
from qgis.core import (
IMHO the issue with non-ASCII characters shall not arise anymore, due to improvements that were done in software since 2017 year. Perhaps the problem was about the PyQGIS's version or OS settings.
Nowadays the geoding of 'Hacettepe Üniversitesi' object works well with both GeoPy (as was mentioned by @ivan) and "GeoCoding" Plugin using PyQGIS.
There is a possibility of using a "Field calculator" inside the Graphical Modeler.
Let's assume there is a point layer 'test' with some features in it, see the image below
Thereafter I created a simple model for reverse geocoding as following:
where a "Field calculator" possess the following parameters
In the 'Formula' tab apply this ...
GeoServer has no geocoding functionality built in. There is however a number of open source geocoders out there, this site offers a list (not sure if it's complete or up to date, just sharing as an example):
If you need the GeoCoding to happen through a OGC compliant service, wrapping in a WPS process would be ...