Getting a bit tired repeating myself: As a developer I would like to specify that certain UI elements are only visible in the context of a user’s language. This is instrumental when dealing with localized database content (e.g., a reference to categories, displaying the english category names within the english UI and dutch category names when users are using the dutch UI.).
Originally, I was asking for a system variable [%UserLanguage%].
Alternatively, you could implement it in a way similar to the role-based visibility: Visibility could either be role-based, language-based, attribute-based or using an expression. Language-based visibility would then list all languages selected for the application and offer checkboxes to set / unset visibility for the respective language.