You can encode hidden, non-printing characters between the data in Code 128 barcodes. For example, you can encode the characters that represent the prefix and the delimiter as part of the Code 128 barcode standard. The application that reads the barcode then decodes the meaning of these characters.Some characters are reserved for use as non-printing characters in Code 128 barcodes. To encode these characters in a barcode, use the following mechanism in LiveCycle Designer ES.