Articulate Studio 360 adds a language attribute to the HTML tag in your published output to identify the course language for screen readers.
You can see the language identifier by opening the following files in a text editor, such as Notepad. The language identifier is on the second line of code. For example, it'll be
lang="fr-FR" for French (France).
|Authoring Tool||Flash Output||HTML5 Output|
You don't have to do anything to enable the language identifier. It's always enabled. It matches the language you select for your player text labels. See these user guides to learn more about player text labels: