Manual:$wgLoginLanguageSelector

Language, regional and character encoding settings: $wgLoginLanguageSelector
Show a bar of language selection links in the user login and user registration forms.
Introduced in version:1.7.0 (r14901)
Removed in version:Still in use
Allowed values:(boolean)
Default value:false

Details

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Set this to true to show a bar of language selection links in the user login and user registration forms. Edit the "loginlanguagelinks" message to customize these options.