Fallbacks

Regional language codes fallback to their parents. So en-BZ fallsback to en automatically (and without configuration).

To define generic fallbacks for all languages:

config.i18n.fallbacks = [:en, :'en-GB']

If you still need custom fallbacks, use:

config.i18n.fallbacks = I18n::Locale::Fallbacks.new(:'en-GB', :'de-AT' => :de)

More details: https://github.com/ruby-i18n/i18n/blob/master/lib/i18n/locale/fallbacks.rb