| 摘要 |
<p>A coded card on which is encoded, by way of a card writing means, prescribed digits and characters, expressed in a two dimensional nested figure code. The digits and characters representing information are encoded on the card according to an encoding protocol using a variety of encoding variables. The encoding protocol used uniquely corresponds to a key code and is selected from a plurality of protocols and identified with the coded card by imprinting the corresponding key code on the card in a specified location. The key code is itself a two dimensional nested figure code of the same variety as the two dimensional nested figure codes that encode the main encoded information. The key code is read by a standard key reading protocol that does not change from card to card in the way that the main decoding protocol changes. <IMAGE></p> |
