>Viv,
>
>Is 104 the start code?

Hi,

It's the CODE B Start code. Code 128 has three different character sets - A,B,C. A is hardly used - it includes representations of old teletype functions. B is used where the barcode has to contain alphabetic characters, C where the content consists of numeric data only (this allows two digits to be compressed into one bar pattern). The value 104 is the CODE B start code - i.e it indicates that the following bar patterns should be interpreted as characters from the CODE B set.

It's possible to switch between character sets within a barcode. If you're in CODE B and have more than four consecutive digits coming up then, in theory, it is worth switching to CODE C

HTH,
Viv