KDE_LANG
Language locale setting to use. This option makes it possible to set another language environment for a program than what is the default. The correct language pack for this language has to be installed for this option to work. The default language when there is none set is en_US. When deciding upon a language, the following resources are looked up, in order: KDE_LANG, configuration file, LC_CTYPE, LC_MESSAGES, LC_ALL, LANG.