Card for a pledge lock

A pledge lock system for trolleys of a shop, comprising:

• a plurality of trolleys each provided with a respective pledge lock having a connecting member engaged in a pledge lock of another trolley, said pledge locks having movable members movably mounted in the respective locks actuatable to release the connecting members;
• a card for magnetically actuating said pledge locks and comprising at least one of a metallic zone and a magnetic zone disposed between two plastic surfaces, a movable member of one of said pledge locks being magnetically actuated upon insertion of said card into said one of said pledge locks;
• a magnetic strip on said card carrying information and on which information can be stored;
• and
• a read/write apparatus at a checkout, entry or exit of said shop cooperating with said magnetic strip for storing information thereon and deriving information stored on said magnetic strip.