Another possible difference will depend on how you reply to this: there's a difference between being played and coming into play.
Indeed. This was one of the first questions asked. I actually may change the wording to "coming into play".
Clearly both cases stop players from casting the card itself from their hand, but the key difference is whether or not effects such as PU, mitosis, and deja vu get blocked.
I think those effects should be blocked in this case or the card will be too limited in its utility.
If the lockdown were instead a side effect, then I could use "being played" instead, which would only restrict playing the card itself from hand, but not making copies with other effects.
I'm open too feedback in that regard though.
I checked out Parergy and didn't see alot of discussion on that topic in particular, so hopefully I can get some more feedback here.