A telephone calling card or debit card is formed as a planar card member having front and rear surfaces. A scratch-off label strip is adhered to one of the surfaces and includes an opaque label strip applied onto the surface of the card. A PIN code is applied onto the opaque label strip. A scratch-off...http://www.google.de/patents/US6561416?utm_source=gb-gplus-sharePatent US6561416 - Debit card having secure scratch-off label strip and method of applying same
