Good question. No idea.
In which year bar-codes become a "mandatory" requirement for scents?
All my bottles report the bar-code since 1998 onwards.
(that could be for practical purpose: it's a fast way to check "vintage" bottles)
Have to check that out.
Find just now a frag with bar-code on the box, batch year 1996.
I think we can assume that if the barcode on the box is missing, this means it's before 1996.
Sometimes could be useful.