Aztec Code is a high density 2 dimensional matrix style bar code symbology that can encode up to 3832 numeric or 3067 alphabetic characters or 1914 bytes of data. The symbol is built on a square grid with a bulls-eye pattern at its center. Data is encoded in a series of "layers" that circle around the bullseye pattern. Each additional layer completely surrounds the previous layer thus causing the symbol to grow in size as more data is encoded yet the symbol remains square. Aztec's primary features include: a wide range of sizes allowing both small and large messages to be encoded, orientation independent scanning and a user selectable error correction mechanism.