Promoted types accepted without language extensions

We discovered that GHC and GHCi (7.4.1) accept promoted types without specifying language extensions (and even when specifying -XHaskell98). For example, promoted lists are accepted: Prelude> type T = [Int,Char] Prelude> :i T type T = (:) * Int ((:) * Char ([] *)) -- Defined at <interactive>:2:6 Also, promoted datatypes:

data N = Z type T = 'Z

I'm guessing you can't use these types anywhere (since they are not kind *), so they won't be very useful, but it seems like this should be disallowed. Regards, Sean