A code 49 symbol is a stacked symbol containing between 2 and 8 rows, each separated by a separator bar.

Each row contains 16 “words” (which are generated from character pairs) and a start and stop character. The last row also contains the number of rows in the symbol and the check digit characters.
There are 2400 possible words which can be generated from each pair of characters (by taking the value of the right hand character plus 49 time the value of the left hand character). Symbols with less than 7 rows contain 2 check digits in the final row. Symbols with 7 or 8 rows contain 3 check digits in the final row.
A numeric mode allows 5 digits to be encoded in the same space as three alphanumeric characters, so offering a higher density.
Encoding code 49 symbols may be accomplished in Auto mode.
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