Each Code 16K symbol contains from 2 to 16 rows, with 5 ASCII characters per row. Additionally, up to 107 16-row symbols can be concatenated together to allow encoding of up to 8,025 ASCII characters, or 16,050 numeric digits. In the extended mode, the first three characters in each 16 row symbol defines the mode character, the order of the 16 row symbol in the block, and the total number of symbols in the block.