Code 128 is a barcode symbology that can be used to encode all 128 characters of ASCII (including uppercase and lower case letters). In terms of representing numerals, code 128 has an advantage over code 39 in that these can be encoded in pairs, thus saving space. This alphanumeric barcode symbology (also compatible with the HIBC standard) employs four bars of varying widths.
Where label space is limited and numerical data and lowercase letters also need to be encoded, use of code 128 is the alternative of choice. Code 128 also employs an extremely efficient, purely numerical packing system that allows the generation of high density barcodes. However, not all barcode scanners are able to read code 128 barcodes. Hence, before you decide in favour of routine use of code 128, it is advisable to make sure your barcode scanners can read the corresponding barcodes!