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.

Concept
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".

Blue Card
The Blue Card (ブルーカード) contains an algorithm that was created by Shibumi. It exists to create digital connections and does so in any way possible, much like the Digi-Gnomes. The Blue Cards use emotions and faith to make ideas real, and as a result, any card can be transformed into a Blue Card once you understand how they work. Also, due to this nature, it can be used in many different ways.

The swipe of a Blue Card into a card scanner or a similar card reading device can transform the device into a D-Power, linking a human together with a Digimon as partner and Tamer. When this happened, a Digimon in the would be brought across the dimensions and bio-emerge the Real World.

Similarly, the Blue Card algorithm was used to summon into the Real World.

Swiping a Blue Card through a D-Power will release 's powers and allow the user to matrix digivolve to Ultimate. When used in this way, the Tamers call them "Matrix Digivolution" cards.

The Blue Card algorithm was also used to bring Digimon across dimensions into from the Digital World into the Real World.

Red Card
The Red Card (レッド・カード) was created by Shibumi to allow the Tamers to fight inside the D-Reaper without degradation. It works perfectly until the program cancels out the  card's effect due to an error in the algorithm causing the biomerged Digimon to revert to their base forms.