in terms of how you could use it, that would be equivalent to also exporting Secret [...]
well, expect that you cannot use the type's name in signatures, so you'd have to rely on type inference. Out of curiosity I just checked javadoc's behaviour on public class Ex { public interface Show { } static private class Secret implements Show { } public Secret foo () { return new Secret (); } static public class Known implements Show { } public Known bar () { return new Known (); } } and it does generate documentation for all the public identifiers, with a non-linked result type for "foo", and it does not list "Secret" among the "known instances" for Show. Well, then I checked haddock (2.7.2) for module Ex ( foo, bar, Known ) where data Secret = Secret foo = Secret instance Show Secret data Known = Known bar = Known instance Show Known and it behaves identically (does not mention Secret as a known instance). So, is this the behaviour that the original poster wanted? J.W.c