The language Filter uses the Browser Language that the users has defined on his device. The language is in the format of Language-CountryCode. (en-US)
Clickshield searches all installed Browser Languages for a match. A German User that has German (de-DE) installed and as a second language English (en-US) would also be blocked by a English (en) filter. This needs to be considered when setting up the filter.
For testing purposes you can see this website for seeing your browser languages.
List of accepted Languages
"de" All German Languages including Germany, Austrian and Switzerland
de-AT German (Austria)
de-CH German (Switzerland)
If a specific country shall be targeted or rejected - select the Language / Country combination.
de-AT (Users with the language German / Austrian)