Usual (and actual) barcode are 13 numbers (short can
be 8 for special purpose).
Depending your use a lot of those 13 numbers are fixed.
Here a studycase
First 3 is your country; Israel is 729. Can be set from
pref or from a tracker_field_options drop-down menu.
Next 6 is your company number (depending on how
much bacode numbers you need this may change from
7 to 5). Let say 000110 for Tikicompany ltd. Should be
entered for once into the tracker_field_options.
Next 3 is your product number. This let say for tikiwiki
mouse and keyboard set. This we can set serial unique
if the admin want that to be completed auto with a
parametrable auto-increment (sometimes the admin will
prefer for 5 to 5 to preserve capability of new items
insertion between other items if it want to keep
Last number is a verification number. It is auto
generated from a mathematical formula to check the
barcode is real.
It is not out of reach, will weight on tikiwiki pro capability.
I can help with all details needed around barcode.