Ninja Info Cards

Ninja Info Cards are a type of ninja tool where information can be burned on it by using chakra. The cards look blank to the naked eye with the kanji for on the back, but when chakra is applied, various categories of data ranging from information about the Five Great Shinobi Countries to the ninja that inhabit them are displayed on the card, even in 3-D. However, only the person who originally burned the data onto the card is able to retrieve it.Naruto Anime Profiles, Volume 1: Episodes 1-37, page 156
== References ==
de:Ninja-Informationskarten
fr:Carte d'Information Ninja