You could use trackable for those that can be labelled, and not trackable, nontrackable, or untrackable for those that can.
From thefreedictionary.com:
Adj. 1.trackable - capable of being traced or tracked;
Although now that I've typed untrackable, untraceable comes to mind, but I'm not sure it means quite what you want.
EDIT(side note: I've just noticed the site I linked lists traceable as an alternative)
EDIT
While responding to the comment below, I realized a very workable word for this is indexed for those itmes which are labelled/numbered (and non-indexed for those which are not).
EDIT:
Since you have many of each type of item, and are using the barcodes to differentiate between the barcoded items, you could use the terms unique and generic.