At first glance, it kinda sounds like you are talking about a Canary Trap, but that is a detection scheme, not a disinformation scheme.
In this case, I would go with Ostensible to describe a document meant to look genuine, but is actually a diversion.
ADJECTIVE
attributive
Stated or appearing to be true, but not necessarily so.
The plan as a whole would either be Bait or a Diversion (depending on if you are trying to lure the enemy in or away respectively).
