What are localized strings?
Constants of Localized string type can be maintained in multiple languages. During execution time of the automated process, the text contained in the constant is displayed in the preferred language of a user. You can specify a default language. This language is used, if, for example, a language is not specified, or a value is missing.
You must enable the Grouping by locale for e-mail option in ARIS. See Customize infrastructure of the ARIS online help (Manage ARIS > Administrate automated processes > Configure Process Governance > Notifications.