Spatula Systems - Nick Johnson's Barcode Specifications

Extrapolated Barcode Specs

Compiled by Nick Johnson.

Recently I was in Amsterdam, and found to my delight (?) that the newer Dutch Guilder notes have barcodes on them. I wasn't able to equate the barcode type with any other type that I could immediately think of, but determined that it is a 2 of 5 code of some kind.

The encoded number on a Guilder consists of an unnumbered pattern, 10 numbered patterns, and 2 more unnumbered patterns:

The first pattern appears to encode the value of the note:

Note Value	First Pattern
1000	1?
250	2?
100	3
50	4?
25	5
10	6

The last 2 patterns are more of a mystery. I suspect they're a checksum of some kind, but I've yet to work out how to generate the checksum. It appears to never exceed 12 (which makes me think it's a %13 function, which would almost make sense because there are 13 patterns). I'll post an annoucement should I ever figure out how to calculate the last 2 patterns. It's also possible that the last 2 patterns aren't a checksum at all, but rather are a series number, printing institution number, etc.

There are two bar widths just like the other 2 of 5 codes. There are no start/stop patterns, and there is a wide space between each character, which appears to be 2*wide. Here are the patterns, using capital letters for bars and lowercase letters for spaces. W and N mean Wide and Narrow respectively.

Digit Pattern Digit Pattern
0 WwNnN 5 NwNnW
1 NnWnW 6 NwNwN
2 NnWwN 7 WnWnN
3 NnNwW 8 WnNnW
4 NwWnN 9 WnNwN

Using this table, you can figure out the last 2 patterns on your guilder note, and you can quickly determine the starting digit.

Digit	Pattern	Digit	Pattern
0	WwNnN	5	NwNnW
1	NnWnW	6	NwNwN
2	NnWwN	7	WnWnN
3	NnNwW	8	WnNnW
4	NwWnN	9	WnNwN

Codabar	Code 2 of 5	Code 3 of 9	Interleaved 2 of 5
Postnet	UPC	Code 128	Code 16k


Thu Jul 24 11:02:30 PDT 2008		barcode/guilder.src
Updated: Thu Aug 18 2005 9:31.35		Viewed: never