If these two were mentioned in JS's diaries, as we are told, then do we take it they DO exist? That hasn't been defined. Nor has the context in which they were mentioned by JS.
Well, of course the prosecution wouldn't have felt the slightest need to do either of those things - it's been quite effective just to establish that no one has ever heard of them except when IS told OS the tale and then made them his defence in December. We assume the defence will try to make them real when they eventually get going...