What it does
Concealed Position—wait, this isn't a standard Magic keyword. You may be thinking of a card or confusing terms. The closest real mechanics are "hidden" information like face-down permanents (via Morph, Disguise, or Cloak), or perhaps a misremembered name.
If you mean Cloak (from Murders at Karlov Manor): you put a card face-down as a 2/2 creature with ward
, and you can turn it face up anytime for its mana cost. Unlike Disguise, the face-up card can be any card, since you cloaked it blindly. The common mistake: people forget face-down creatures are colorless, nameless 2/2s with no abilities until flipped, and that flipping isn't a spell—it can't be countered.
If you meant a specific card, double-check the exact name and I'll explain precisely how it functions in Commander.
