When using more than 2 sheets of public transportation cards
 (a subway and bus), credit cards of RFID&IC, etc., the Magic
Block Card and various Excess Cards, the Magic Block Card is
used to prevent the occurrence of malfunction and interference
between each Cards and also is used to avoid having unnecessary
 recognition.

For the Cards not in use, you can prevent them from being
recognized by inserting the Magic Block Card in front or rear side
of the cards then no recognition is made.