Code128 barcode is widely used to encode alphanumeric data. A Code 128 barcode has four sections:
Start character
Encoded data
Modulo 103 Check character
Stop character

Code128 has three subsets: A, B and C. Code 128 set A is used to encode ASCII characters 00 to 95 (0–9, A–Z and control codes), special characters, FNC1, FNC2, FNC3 and FNC4.