Digi-Modify

Digi-Modify (カード・スラッシュ) is the term used in Digimon Tamers to refer to the act of modifying a partner Digimon's capabilities through the use of the Japanese Digital Monster Card Game.

Digimon Tamers
In Digimon Tamers, Digimon normally have to absorb data to get stronger. A Digimon partnered with Tamers on the other hand has the capability to temporarily increase its power using cards scanned through the Tamer's D-Power. This act looks like the Tamer is "slashing" their card through the Digivice, hence the Japanese term "Card Slash".

Digimon RPG
In Digimon RPG, Card Slash is the ability for the player to use cards to affect the current battle. The number of available Card Slashes left is depicted on the top left of the UI, while the the top right contains registered Card Slash shortcuts.