Calling card

A calling card is a special card that Sly Cooper uses to replace things he has stolen, or to attract the attention of Inspector Carmelita Fox. They are seen in all four games in the Sly Cooper series. Sly usually places them in safes after he has opened them, or in places where Carmelita can see them, that way Sly and the gang can lure her, or just let her know that the gang was there.

Sly Cooper and the Thievius Raccoonus
Calling cards first appear in Sly Cooper and the Thievius Raccoonus. In "Police Headquarters," Sly Cooper placed one inside the vault in Inspector Carmelita Fox's office. He would do the same thing after stealing items from vaults found in other locations as well.

Trivia

 * In Sly Cooper: Thieves in Time, Murray and Bentley have their own calling cards visible in the safe house.
 * In Infamous 2, Sly's calling card can be seen on Cole MacGrath's backpack.