RTC has some key operation that are process enabled. It means that for a given role, you can decide to enforce some specific rules. There are some pre-defined ones for the most common use cases identified so far. But adding a rule can be done by implementing a plugin.

One of the operation is deliver to a stream. the language definition is a user property set on a file. Here you don't want some class of users to change the user property. It seems that you could write a precondition to enforce that.

Nicolas