Quick question - I've searched this thread (and some others as well) and haven't found the answer.

If there are multiple passengers traveling on the same PNR, is it possible for only one of them to take a VDB, or must all passengers on the same PNR have the same reservations?

I assume I know the answer (that all passengers on same PNR must travel together, i.e. they'd all have to take the same VDB), but I just wanted clarification. Thanks!