A telephone calling card includes a planar card member with a scratch-off label positioned on a surface of the planar card member. The scratch-off label includes a base label having an opaque, releasable film layer and a PIN printed on the opaque, releasable film layer. A scratch-off cover label is secured...http://www.google.de/patents/US6609662?utm_source=gb-gplus-sharePatent US6609662 - Debit card having secure scratch-off label strip with releasable layer and method of applying same
