1. FNC1 in the first position.

Here is the flowchat of how it works:

Here is a example in ISO IEC 18004 :

1.Read the FNC1 indicator : 0101
2.Read the normal indicator : 0001 ->numeric mode
And get the character count indicator 00001101 ->29
3.Read data codewords :

First read 2 codewords : 01 , which can be find in the GS1 AI table

https://www.gs1.org/docs/barcodes/GSCN_16_477_FNC1.pdf

Data length is 14.So the data is load as follows:

Read 2 codewords for the new AI : 15

Data length is 6.So the data is load as follows:

Read 2 codewords for the new AI : 30

Data max length is 8. When meeting the GS(%) character , it finished early and the GS was ignored.


4.Read the normal indicator : 0010 ->Alphanumeric mode
And get the character count indicator 00001001 ->9
5.Read data :

Read 2 codewords : 10

Data max length is 20. Just load all the remaining data.

2. FNC1 in the second position.

Here is the flowchat of how it works:

Here is a example in ISO IEC 18004 :

And my question is that what does the Appliction Indicator ‘37’ mean ? What is the function of this AI in FNC1 IN SECOND POSITION ? Where can I get its format infomation ? Does it follows the same standard as FNC1 IN FIRST POSITION or does it follows other international standards?

Looking forward to hearing from you .
2020.08.06