If you are comfortable looking at database functions, do a search for the formatXXXXbarcode() sql functions. You can see several including ItemSite, location, lot/serial etc. Note there is a prefix in those codes. That prefix tells the xTuple screen, what type of code has been scanned and to put the results in the correct field on the open screen.
This is not a system-wide process, we have to code each relevant screen with the barcode handling, so it is most likely found in the inventory handling screens. Without looking, I cant say what barcode handling might be available in a Sales Order scree.n