ASLANG=language_code
Optional but recommended in non-English environments.
Language_code is the two-letter combination representing a language. For example, setting ASLANG=DE sets the default language to German.
The first of the following values set determines the default language.
ASLANG environment variable
Registry (Windows only) as set by the installer or dblang.exe
Query the operating system
If no language information is set, English is the default.