True. My point was that you could not do that trick with an ordinary deck of cards as you can with other tricks. You can also get trick packs of cards where the decoration on the obverse looks identical, but one part is slightly highlighted, unnoticeable to the punter but clearly recognisable to the performer. As an example, the obverse will be decorated around the edges with the four emblems, ♥,♦.♣.♠ in very small characters. One of those will be ever so slightly emphasised, so by counting the performer knows which card is on the reverse.