The GS1-128 barcode standard defines the structure of data encoding. The standard defines the Application Identifiers (numbers in parenthesis) and the data for each of those Application Identifiers (AI). The AIs can be numeric, alphanumeric, and can have fixed or variable length.
You don't have to enter the FNC1 characters manually into your barcodes. NiceLabel does this automatically, when necessary.
Rules for Encoding FNC1 Character:
NiceLabel inserts the Star Character and FNC1 character at the beginning of the barcode GS1-128 automatically.
NiceLabel adds the FNC1 character at the end of all variable-length AIs. If the value for AI fills all defined characters, or if the value ends prematurely.
NiceLabel adds the FNC1 character at the end of some fixed-length AIs. The GS1-128 General Specifications define exactly when the FNC1 must be added at the end of AIs.
If you use several AIs in the same barcode, put the fixed-length AIs at the beginning and variable-length at the end of the barcode definition.
The last AI in the barcode must not be followed by the FNC1 character, even if it should have the FNC.
The FNC1 character is not a visible character. It does not show in the human interpretation of your barcodes. Only barcode scanners read FNC characters. If you mistakenly insert the FNC characters at the wrong places, NiceLabel encodes them as data values for your barcodes.