Pharmacode

Pharmacode, also known as Pharmaceutical Binary Code, is a barcode standard, used in the pharmaceutical industry as a packing control system. It is designed to be readable despite printing errors. It can be printed in multiple colors as a check to ensure that the remainder of the packaging (which the pharmaceutical company must print to protect itself from legal liability) is correctly printed.

Encoding
Pharmacode can represent only a single integer from 3 to 131070. Unlike other commonly used one-dimensional barcode schemes, pharmacode does not store the data in a form corresponding to the human-readable digits; the number is encoded in binary, rather than decimal. Pharmacode is read from right to left: with $$n$$ as the bar position starting at 0 on the right, each narrow bar adds $$2^n$$ to the value and each wide bar adds $$2\times 2^n$$. The minimum barcode is 2 bars and the maximum 16, so the smallest number that could be encoded is 3 (2 narrow bars) and the biggest is 131070 (16 wide bars).