I applied InternalsVisibleTo to one of my projects in order for its internals to be visible for test projects. However, (this is weird I know) I need to mark a few internal classes so that they won't be visible to the projects which is indicated through InternalsVisibleTo.
Is there any attribute I can apply for this that the compiler is aware of?
Anderson Silva is correct. There is no way to do this. You should consider moving the types to a new assembly. Alternatively, you could think about applying the [EditorBrowsable(EditorBrowsableState.Never)] attribute to hide the types from IntelliSense, although if the user knows about them, the code will compile.